forked from docs/doc-exports
removing old outdated content
Reviewed-by: Kucerak, Kristian <kristian.kucerak@t-systems.com> Reviewed-by: gtema <artem.goncharov@gmail.com> Co-authored-by: Hasko, Vladimir <vladimir.hasko@t-systems.com> Co-committed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com>
This commit is contained in:
parent
a09d4de83b
commit
82495ac3f3
File diff suppressed because it is too large
Load Diff
File diff suppressed because it is too large
Load Diff
@ -1,95 +0,0 @@
|
||||
<a name="elb-03-qy-0001"></a><a name="elb-03-qy-0001"></a>
|
||||
|
||||
<h1 class="topictitle1">Migrating from Classic Load Balancers to Shared Load Balancers</h1>
|
||||
<h4 class="sectiontitle">Scenarios</h4><p id="elb-03-qy-0001__p1506549406">Classic load balancers are no longer provided. It is recommended that you use load balancers instead because they provide comprehensive Layer 7 load balancing and better forwarding performance.</p>
|
||||
|
||||
<h4 class="sectiontitle">Prerequisites</h4><p id="elb-03-qy-0001__p39041252115910">You have the <strong id="elb-03-qy-0001__b1237014117476">Tenant Administrator</strong> permission.</p>
|
||||
|
||||
<h4 class="sectiontitle">Impacts on Traffic Routing</h4><p id="elb-03-qy-0001__p18439151924919">Traffic routing over persistent connections will be interrupted during migration and rollback. For the impact on traffic routing over short connections, see the following table.</p>
|
||||
|
||||
<table cellpadding="4" cellspacing="0" summary="" id="elb-03-qy-0001__table189291540135319" frame="border" border="1" rules="all"><caption><b>Table 1 </b>Impact on traffic routing over short connections</caption><thead align="left"><tr id="elb-03-qy-0001__row593094095319"><th align="left" class="cellrowborder" valign="top" width="16%" id="mcps1.3.3.3.2.5.1.1"><p id="elb-03-qy-0001__p159301340195316">Scenario</p>
|
||||
</th>
|
||||
<th align="left" class="cellrowborder" valign="top" width="24%" id="mcps1.3.3.3.2.5.1.2"><p id="elb-03-qy-0001__p13930174014536">During Migration</p>
|
||||
</th>
|
||||
<th align="left" class="cellrowborder" valign="top" width="32%" id="mcps1.3.3.3.2.5.1.3"><p id="elb-03-qy-0001__p993074015316">Before Finishing Migration</p>
|
||||
</th>
|
||||
<th align="left" class="cellrowborder" valign="top" width="28.000000000000004%" id="mcps1.3.3.3.2.5.1.4"><p id="elb-03-qy-0001__p793064065313">Rollback</p>
|
||||
</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody><tr id="elb-03-qy-0001__row893034018537"><td class="cellrowborder" valign="top" width="16%" headers="mcps1.3.3.3.2.5.1.1 "><p id="elb-03-qy-0001__p11930104011534">Migrating a private network load balancer</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="24%" headers="mcps1.3.3.3.2.5.1.2 "><p id="elb-03-qy-0001__p129311240195311">Not interrupted</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="32%" headers="mcps1.3.3.3.2.5.1.3 "><p id="elb-03-qy-0001__p2931540155314">On a client that is on the same subnet as the load balancer, run the <strong id="elb-03-qy-0001__b15145291516">arping -b</strong> <em id="elb-03-qy-0001__i1676433725">Private IP address of the classic load balancer</em> command to refresh ARP entries to ensure service continuity.</p>
|
||||
<p id="elb-03-qy-0001__p1722433611409">If ARP entries are not refreshed, traffic from this client will be interrupted. The interruption duration is the ARP aging period, which ranges from 30s to 300s, depending on parameter settings of the client.</p>
|
||||
<span class="notetitle"> NOTE: </span><p id="elb-03-qy-0001__p3351128104620">The private IP address of the classic load balancer is bound to the shared load balancer.</p>
|
||||
</div>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="28.000000000000004%" headers="mcps1.3.3.3.2.5.1.4 "><p id="elb-03-qy-0001__p157612623613">If ARP entries are not refreshed, traffic from the client is interrupted. The interruption duration is the ARP aging period, which ranges from 30s to 300s, depending on parameter settings of the client.</p>
|
||||
<p id="elb-03-qy-0001__p1893124065313">To refresh ARP entries and shorten the interruption duration to a few seconds, run the <strong id="elb-03-qy-0001__b47991431945">arping -b</strong> <em id="elb-03-qy-0001__i118120498518">Private IP address of the classic load balancer</em> command on the client.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb-03-qy-0001__row2931640115319"><td class="cellrowborder" valign="top" width="16%" headers="mcps1.3.3.3.2.5.1.1 "><p id="elb-03-qy-0001__p1793117409533">Migrating a public network load balancer with the EIP changed</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="24%" headers="mcps1.3.3.3.2.5.1.2 "><p id="elb-03-qy-0001__p1593124035313">Not interrupted</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="32%" headers="mcps1.3.3.3.2.5.1.3 "><p id="elb-03-qy-0001__p1893164075316">Before you click <strong id="elb-03-qy-0001__b17785917172812">Finish Migration</strong>, ensure that the domain name has been mapped to the new EIP of the newly created <span id="elb-03-qy-0001__ph190314235711">shared</span> load balancer.</p>
|
||||
<p id="elb-03-qy-0001__p6310114804111">If the new EIP has not been configured, traffic is still routed by the classic load balancer. After you click <strong id="elb-03-qy-0001__b158072202466">Finish Migration</strong>, traffic routing will be interrupted.</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="28.000000000000004%" headers="mcps1.3.3.3.2.5.1.4 "><p id="elb-03-qy-0001__p179312409533">Before you click <strong id="elb-03-qy-0001__b51431640203415">Roll Back</strong>, map the domain name to the EIP of the classic load balancer.</p>
|
||||
<p id="elb-03-qy-0001__p198358215424">If the EIP is not configured, traffic is still routed by the <span id="elb-03-qy-0001__ph78591872585">shared</span> load balancer. After you click <strong id="elb-03-qy-0001__b12873143184613">Finish Migration</strong>, traffic routing will be interrupted.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb-03-qy-0001__row1293124045315"><td class="cellrowborder" valign="top" width="16%" headers="mcps1.3.3.3.2.5.1.1 "><p id="elb-03-qy-0001__p1493194016537">Migrating a public network load balancer without changing the EIP</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="24%" headers="mcps1.3.3.3.2.5.1.2 "><p id="elb-03-qy-0001__p139311440165314">After the <span id="elb-03-qy-0001__ph1269783510588">shared</span> load balancer is created, traffic will be interrupted for about 5s, during which the EIP is released from the classic public network load balancer and bound to the <span id="elb-03-qy-0001__ph13765643145813">shared</span> load balancer.</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="32%" headers="mcps1.3.3.3.2.5.1.3 "><p id="elb-03-qy-0001__p8931240105315">Not interrupted</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="28.000000000000004%" headers="mcps1.3.3.3.2.5.1.4 "><p id="elb-03-qy-0001__p6931164015312">Not interrupted</p>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
|
||||
|
||||
<h4 class="sectiontitle">Migration Process</h4><p id="elb-03-qy-0001__p281955433916">The following are migration processes for three scenarios:</p>
|
||||
|
||||
<ul id="elb-03-qy-0001__ul2941172874017"><li id="elb-03-qy-0001__li59411028114017">Migrating a private network load balancer<span class="figcap"><b>Figure 1 </b>Migration process</span><br><span><img id="elb-03-qy-0001__image461035665614" src="en-us_image_0000001115974588.png"></span>
|
||||
</li><li id="elb-03-qy-0001__li114108374410">Migrating a public network load balancer with the EIP changed<span class="figcap"><b>Figure 2 </b>Migration process</span><br><span><img id="elb-03-qy-0001__image115925713365" src="en-us_image_0000001115981688.png"></span>
|
||||
</li><li id="elb-03-qy-0001__li19542042134218">Migrating a public network load balancer without changing the EIP<span class="figcap"><b>Figure 3 </b>Migration process</span><br><span><img id="elb-03-qy-0001__image106861835163617" src="en-us_image_0000001115974770.png"></span>
|
||||
</li></ul>
|
||||
<h4 class="sectiontitle">Migrating a Classic Load Balancer</h4><ol id="elb-03-qy-0001__ol1889111542441"><li id="elb-03-qy-0001__li104941610595">Log in to the management console.</li><li id="elb-03-qy-0001__li15494614592">In the upper left corner of the page, click <span><img id="elb-03-qy-0001__en-us_topic_0240829509_image177714713415" src="en-us_image_0241356603.png"></span> and select the desired region and project.</li><li id="elb-03-qy-0001__li83736197297">Hover on <span><img id="elb-03-qy-0001__en-us_topic_0052569751_en-us_topic_0052569751_image616618613" src="en-us_image_0000001120894978.png"></span> in the upper left corner to display <strong id="elb-03-qy-0001__en-us_topic_0052569751_b9121102522212">Service List</strong> and choose <strong id="elb-03-qy-0001__en-us_topic_0052569751_b61222025142217">Network</strong> > <strong id="elb-03-qy-0001__en-us_topic_0052569751_b4124425142210">Elastic Load Balancing</strong>.</li><li id="elb-03-qy-0001__li786163214298">In the classic load balancer list, locate the load balancer you want to migrate and choose <strong id="elb-03-qy-0001__b49398450483">More</strong> > <strong id="elb-03-qy-0001__b71311750104819">Migrate</strong>.</li><li id="elb-03-qy-0001__li649416466551">Check whether the load balancer to be migrated is a private network load balancer.<ul id="elb-03-qy-0001__ul51995182116"><li id="elb-03-qy-0001__li22075142111">If it is a private network load balancer, go to <a href="#elb-03-qy-0001__li640652442318">6</a>.</li><li id="elb-03-qy-0001__li13371010192210">If it is not a private network load balancer, go to <a href="#elb-03-qy-0001__li10489153014143">7</a>.</li></ul>
|
||||
</li><li id="elb-03-qy-0001__li640652442318"><a name="elb-03-qy-0001__li640652442318"></a><a name="li640652442318"></a>Run command <strong id="elb-03-qy-0001__b209351654148">arping -b</strong> <em id="elb-03-qy-0001__i12947173013282">Private IP address of the classic load balancer</em> on the client that is on the same subnet as the load balancer to update the ARP entries. Then, go to <a href="#elb-03-qy-0001__li1683144311213">11</a>.<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb-03-qy-0001__p91305196495">The private IP address of the classic load balancer is bound to the shared load balancer. </p>
|
||||
</div>
|
||||
</li><li id="elb-03-qy-0001__li10489153014143"><a name="elb-03-qy-0001__li10489153014143"></a><a name="li10489153014143"></a>Determine whether you want to change the EIP.<ul id="elb-03-qy-0001__ul18223101261515"><li id="elb-03-qy-0001__li189491015151518">If you want to change the EIP, go to <a href="#elb-03-qy-0001__li15100834181518">8</a>.</li><li id="elb-03-qy-0001__li094971531516">If you do not want to change the EIP, go to <a href="#elb-03-qy-0001__li16313204716">10</a>.</li></ul>
|
||||
</li><li id="elb-03-qy-0001__li15100834181518"><a name="elb-03-qy-0001__li15100834181518"></a><a name="li15100834181518"></a>Modify the DNS configuration to map the domain name to the EIP bound to the <span id="elb-03-qy-0001__ph1478815116584">shared</span> load balancer.</li><li id="elb-03-qy-0001__li1551111194188">Switch to the Cloud Eye console, view monitoring data of the classic load balancer and then go to <a href="#elb-03-qy-0001__li1683144311213">11</a>.<p id="elb-03-qy-0001__p10907920171914">If both the number of concurrent connections and the number of new connections are 0, traffic is diverted to the shared load balancer.</p>
|
||||
</li><li id="elb-03-qy-0001__li16313204716"><a name="elb-03-qy-0001__li16313204716"></a><a name="li16313204716"></a>Send requests to the shared load balancer to test whether it can route requests to associated backend servers.</li><li id="elb-03-qy-0001__li1683144311213"><a name="elb-03-qy-0001__li1683144311213"></a><a name="li1683144311213"></a>Locate the classic load balancer that has been migrated and choose <strong id="elb-03-qy-0001__b1836355571510">More</strong> > <strong id="elb-03-qy-0001__b88723151615">Finish Migration</strong>.<p id="elb-03-qy-0001__p2474631951">The classic load balancer will be automatically deleted.</p>
|
||||
</li><li id="elb-03-qy-0001__li24042022165615">Switch to the load balancer list and view the newly created <span id="elb-03-qy-0001__ph10824156145813">shared</span> load balancer.</li></ol>
|
||||
|
||||
<h4 class="sectiontitle">Rolling Back to a Classic Load Balancer</h4><p id="elb-03-qy-0001__p16152102265020">If you decide to roll back, the newly created <span id="elb-03-qy-0001__ph128196035919">shared</span> load balancer will be deleted, and the original classic load balancer will be restored.</p>
|
||||
<ol id="elb-03-qy-0001__ol20815325522"><li id="elb-03-qy-0001__li1627817613189">Log in to the management console.</li><li id="elb-03-qy-0001__li1927811621813">In the upper left corner of the page, click <span><img id="elb-03-qy-0001__en-us_topic_0240829509_image177714713415_1" src="en-us_image_0241356603.png"></span> and select the desired region and project.</li><li id="elb-03-qy-0001__li17301740102218">Hover on <span><img id="elb-03-qy-0001__en-us_topic_0052569751_en-us_topic_0052569751_image616618613_1" src="en-us_image_0000001120894978.png"></span> in the upper left corner to display <strong id="elb-03-qy-0001__en-us_topic_0052569751_b9121102522212_1">Service List</strong> and choose <strong id="elb-03-qy-0001__en-us_topic_0052569751_b61222025142217_1">Network</strong> > <strong id="elb-03-qy-0001__en-us_topic_0052569751_b4124425142210_1">Elastic Load Balancing</strong>.</li><li id="elb-03-qy-0001__li1481133295216">In the classic load balancer list, locate the load balancer you want to roll back and choose <strong id="elb-03-qy-0001__b281364818535">More</strong> > <strong id="elb-03-qy-0001__b4814748145320">Roll Back</strong>.<p id="elb-03-qy-0001__p1277510528525">Alternatively, select the load balancer you want to roll back and click <strong id="elb-03-qy-0001__b318445195612">Roll Back</strong> above the load balancer list.</p>
|
||||
</li></ol>
|
||||
|
||||
<h4 class="sectiontitle">Batch Migration or Rollback</h4><ol id="elb-03-qy-0001__ol536616319219"><li id="elb-03-qy-0001__li1381919199186">Log in to the management console.</li><li id="elb-03-qy-0001__li781971941812">In the upper left corner of the page, click <span><img id="elb-03-qy-0001__en-us_topic_0240829509_image177714713415_2" src="en-us_image_0241356603.png"></span> and select the desired region and project.</li><li id="elb-03-qy-0001__li199391552112515">Hover on <span><img id="elb-03-qy-0001__en-us_topic_0052569751_en-us_topic_0052569751_image616618613_2" src="en-us_image_0000001120894978.png"></span> in the upper left corner to display <strong id="elb-03-qy-0001__en-us_topic_0052569751_b9121102522212_2">Service List</strong> and choose <strong id="elb-03-qy-0001__en-us_topic_0052569751_b61222025142217_2">Network</strong> > <strong id="elb-03-qy-0001__en-us_topic_0052569751_b4124425142210_2">Elastic Load Balancing</strong>.</li><li id="elb-03-qy-0001__li1836713317219">In the classic load balancer list, select the load balancers and click <strong id="elb-03-qy-0001__b5537148105817">Migrate</strong> or <strong id="elb-03-qy-0001__b7311102515581">Roll Back</strong>.</li><li id="elb-03-qy-0001__li1020131015155">Perform subsequent operations as needed.<ul id="elb-03-qy-0001__ul026214831513"><li id="elb-03-qy-0001__li826294831514">If you choose <strong id="elb-03-qy-0001__b81871462162">Migrate</strong>, go to <a href="#elb-03-qy-0001__li1960334510517">6</a>.</li><li id="elb-03-qy-0001__li869202118166">If you choose <strong id="elb-03-qy-0001__b779763719128">Roll Back</strong>, no further operations are required.</li></ul>
|
||||
</li><li id="elb-03-qy-0001__li1960334510517"><a name="elb-03-qy-0001__li1960334510517"></a><a name="li1960334510517"></a>Check whether the load balancers to be migrated are private network load balancers.<ul id="elb-03-qy-0001__ul186030451159"><li id="elb-03-qy-0001__li206039452058">If they are private network load balancers, go to <a href="#elb-03-qy-0001__li126031845051">7</a>.</li><li id="elb-03-qy-0001__li10603144514510">If they are not private network load balancers, go to <a href="#elb-03-qy-0001__li134286139103">8</a>.</li></ul>
|
||||
</li><li id="elb-03-qy-0001__li126031845051"><a name="elb-03-qy-0001__li126031845051"></a><a name="li126031845051"></a>After the migration, run command <strong id="elb-03-qy-0001__b865535371715">arping -b</strong> <em id="elb-03-qy-0001__i2121194623114">Private IP address of each classic load balancer</em> on the client that is on the same subnet as the load balancer to update the ARP entries. Then, go to <a href="#elb-03-qy-0001__li16906018234">12</a>.<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb-03-qy-0001__p1760494510519">The private IP address of the classic load balancer will be bound to the shared load balancer. </p>
|
||||
</div>
|
||||
</li><li id="elb-03-qy-0001__li134286139103"><a name="elb-03-qy-0001__li134286139103"></a><a name="li134286139103"></a>Determine whether you want to change the EIP.<ul id="elb-03-qy-0001__ul1942871311019"><li id="elb-03-qy-0001__li5428101351017">If you want to change the EIP, go to <a href="#elb-03-qy-0001__li2438528242">9</a>.</li><li id="elb-03-qy-0001__li15428151317105">If you do not want to change the EIP, go to <a href="#elb-03-qy-0001__li1243832192415">11</a>.</li></ul>
|
||||
</li><li id="elb-03-qy-0001__li2438528242"><a name="elb-03-qy-0001__li2438528242"></a><a name="li2438528242"></a>Modify the DNS configuration to map the domain name to the EIP bound to each <span id="elb-03-qy-0001__ph175101168597">shared</span> load balancer.</li><li id="elb-03-qy-0001__li3438192112411">Switch to the Cloud Eye console, view monitoring data of each classic load balancer and then go to <a href="#elb-03-qy-0001__li16906018234">12</a>.<p id="elb-03-qy-0001__p194383272417">If both the number of concurrent connections and the number of new connections are 0, traffic is diverted to the shared load balancers.</p>
|
||||
</li><li id="elb-03-qy-0001__li1243832192415"><a name="elb-03-qy-0001__li1243832192415"></a><a name="li1243832192415"></a>Send requests to shared load balancers to test whether they can route requests to associated backend servers.</li><li id="elb-03-qy-0001__li16906018234"><a name="elb-03-qy-0001__li16906018234"></a><a name="li16906018234"></a>Select all classic load balancers that have been migrated and click <strong id="elb-03-qy-0001__b144374370180">Finish Migration</strong>.<p id="elb-03-qy-0001__p147528611236">These classic load balancers will be automatically deleted.</p>
|
||||
</li><li id="elb-03-qy-0001__li636713311217">Switch to the load balancer list, view the newly created <span id="elb-03-qy-0001__ph337616107593">shared</span> load balancers.</li></ol>
|
||||
|
||||
<h4 class="sectiontitle">Causes of Migration Failure</h4><p id="elb-03-qy-0001__p69831421589">The following are possible causes why a classic load balancer cannot be migrated:</p>
|
||||
|
||||
<ul id="elb-03-qy-0001__ul18244185983414"><li id="elb-03-qy-0001__li17244159183413">The quota of the <span id="elb-03-qy-0001__ph19885131812593">shared</span> load balancer, listener, backend server group, or certificate is insufficient.</li><li id="elb-03-qy-0001__li1193932763514">The classic load balancer is not in the <strong id="elb-03-qy-0001__b1556642814359">Running</strong> state.</li><li id="elb-03-qy-0001__li1553523733517">The classic load balancer listener is not in the <strong id="elb-03-qy-0001__b254043743517">Running</strong> state.</li><li id="elb-03-qy-0001__li314394443519">The <span id="elb-03-qy-0001__ph321433165917">shared</span> load balancer does not support the SSL protocol.</li></ul>
|
||||
<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><ul id="elb-03-qy-0001__ul1423210194546"><li id="elb-03-qy-0001__li22321193543">During the migration, the listeners and backend servers of the classic load balancer are also migrated. Your applications and data will not be affected. To ensure successful migration, ensure that backend servers can be accessed from 100.125.0.0/16.</li><li id="elb-03-qy-0001__li523281912547">After the migration, the original classic load balancer will be deleted and cannot be restored, and its private IP address and EIP will be used by the newly created shared load balancer. If the classic load balancer does not have an EIP, you can bind one to the newly created shared load balancer.</li><li id="elb-03-qy-0001__li1198695120319">During batch migration of public network load balancers, ensure that the number of EIPs and the number of load balancers are the same. After the migration, the system automatically binds one EIP to each <span id="elb-03-qy-0001__ph1622424725913">shared</span> load balancer in sequence.</li><li id="elb-03-qy-0001__li172321519125414">Integration with the AS service becomes invalid after the migration. Configure AS if you want to scale the number of backend servers associated with each shared load balancer.</li><li id="elb-03-qy-0001__li192321519155412">Access logs stored in the OBS bucket are lost because shared load balancers do not support access logging.</li></ul>
|
||||
</div>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_ug_qy_0002.html">Load Balancer Migration</a>
|
||||
|
||||
|
||||
|
||||
@ -1,27 +0,0 @@
|
||||
<a name="elb_faq_0000"></a><a name="elb_faq_0000"></a>
|
||||
|
||||
<h1 class="topictitle1">FAQs</h1>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0200.html">Popular Questions</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0212.html">ELB Use</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0201.html">Load Balancer</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0202.html">Listener</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0203.html">Backend Server</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0204.html">Health Check</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0170.html">Obtaining Source IP Addresses</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0180.html">HTTP/HTTPS Listener</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0190.html">Sticky Session</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
@ -1,11 +0,0 @@
|
||||
<a name="elb_faq_0001"></a><a name="elb_faq_0001"></a>
|
||||
|
||||
<h1 class="topictitle1">When Is a Backend Server Considered Healthy?</h1>
|
||||
<p id="elb_faq_0001__p1380411575918">If a backend server is associated with a load balancer for the first time, the backend server is considered healthy after one health check. After this, the server is detected healthy after the maximum retries of health checks.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0203.html">Backend Server</a>
|
||||
|
||||
|
||||
|
||||
@ -1,43 +0,0 @@
|
||||
<a name="elb_faq_0024"></a><a name="elb_faq_0024"></a>
|
||||
|
||||
<h1 class="topictitle1">How Does ELB Perform UDP Health Checks? What Are the Precautions for UDP Health Checks?</h1>
|
||||
<h4 class="sectiontitle">How UDP Health Checks Work</h4><p id="elb_faq_0024__p594001812332">UDP is a connectionless protocol, and a UDP health check is implemented as follows:</p>
|
||||
|
||||
<ol id="elb_faq_0024__ol1625104034212"><li id="elb_faq_0024__li3625154010423">The health check node sends an ICMP request message to the backend server based on the health check configuration.<ul id="elb_faq_0024__ul202464854211"><li id="elb_faq_0024__li624114811423">If the health check node receives an ICMP reply message from the backend <span id="elb_faq_0024__text1730504215713">server</span>, it considers the backend server healthy and continues the health check.</li><li id="elb_faq_0024__li1644615164212">If the health check node does not receive an ICMP reply message from the backend <span id="elb_faq_0024__text166053611810">server</span>, it considers the backend server unhealthy.</li></ul>
|
||||
</li><li id="elb_faq_0024__li156251040174211">After receiving the ICMP reply message, the health check node sends a UDP probe packet to the backend <span id="elb_faq_0024__text279319651018">server</span>.<ul id="elb_faq_0024__ul1611085454217"><li id="elb_faq_0024__li211065416424">If the health check node receives an ICMP Port Unreachable message from the backend <span id="elb_faq_0024__text73403324109">server</span> within the timeout duration, the backend server is considered unhealthy.</li><li id="elb_faq_0024__li9969105615423">If the health check node does not receive an ICMP Port Unreachable message from the backend <span id="elb_faq_0024__text02196153811">server</span> within the timeout duration, the backend server is considered healthy.</li></ul>
|
||||
</li></ol>
|
||||
<p id="elb_faq_0024__p20843183062817">When you use UDP for health checks, retain default parameter settings.</p>
|
||||
<h4 class="sectiontitle">Troubleshooting Procedure</h4><p id="elb_faq_0024__p1290856173312">If the backend server is unhealthy, use either of the following methods to locate the fault:</p>
|
||||
|
||||
<ol id="elb_faq_0024__ol39671049113310"><li id="elb_faq_0024__li3967124911331">Check whether the timeout duration is too short.<p id="elb_faq_0024__p1247644393018"><a name="elb_faq_0024__li3967124911331"></a><a name="li3967124911331"></a>A possible cause is that the ICMP Echo Reply or ICMP Port Unreachable message returned by the backend <span id="elb_faq_0024__text11635124113813">server</span> does not reach the health check node within the timeout duration. As a result, the health check result is inaccurate.</p>
|
||||
<p id="elb_faq_0024__p747610439305">It is recommended that you change the timeout duration to a larger value.</p>
|
||||
<p id="elb_faq_0024__p18541632193414">UDP health checks are different from other health checks. If the health check timeout duration is too short, the health check result of the backend <span id="elb_faq_0024__text13586581185">server</span> changes between <strong id="elb_faq_0024__b44605421747">Healthy</strong> and <strong id="elb_faq_0024__b1292844517410">Unhealthy</strong> frequently.</p>
|
||||
</li><li id="elb_faq_0024__li2179122153411">Check whether the backend <span id="elb_faq_0024__text257519920910">server</span> restricts the rate at which ICMP messages are generated.</li></ol>
|
||||
<p id="elb_faq_0024__p1647644393017">For Linux servers, run the following commands to query the rate limit and rate mask:</p>
|
||||
<pre class="screen" id="elb_faq_0024__screen4768112823913">sysctl -q net.ipv4.icmp_ratelimit</pre>
|
||||
<p id="elb_faq_0024__p1811918431964">The default rate limit is <strong id="elb_faq_0024__b842352706193458">1000</strong>.</p>
|
||||
<pre class="screen" id="elb_faq_0024__screen7265195210611">sysctl -q net.ipv4.icmp_ratemask</pre>
|
||||
<p id="elb_faq_0024__p52451533713">The default rate mask is <strong id="elb_faq_0024__b1330606519">6168</strong>.</p>
|
||||
<p id="elb_faq_0024__p74763433302">If the returned value of the first command is the default value or <strong id="elb_faq_0024__b842352706103935">0</strong>, run the following command to remove the rate limit of Port Unreachable messages:</p>
|
||||
<pre class="screen" id="elb_faq_0024__screen187541426251">sysctl -w net.ipv4.icmp_ratemask=6160</pre>
|
||||
<p id="elb_faq_0024__p178268102918">For more information, see the <em id="elb_faq_0024__i842352697103837">Linux Programmer's Manual</em>. On the Linux CLI, run the following command to display the manual:</p>
|
||||
<pre class="screen" id="elb_faq_0024__screen58180101999">man 7 icmp</pre>
|
||||
<p id="elb_faq_0024__p184947035312">Alternatively, visit <a href="http://man7.org/linux/man-pages/man7/icmp.7.html" target="_blank" rel="noopener noreferrer">http://man7.org/linux/man-pages/man7/icmp.7.html</a>.</p>
|
||||
<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_faq_0024__p07231750353">Once the rate limit is lifted, the number of ICMP Port Unreachable messages on the backend server will not be limited.</p>
|
||||
</div>
|
||||
<h4 class="sectiontitle">Precautions</h4><p id="elb_faq_0024__p07313917363">Note the following when you configure UDP health checks:</p>
|
||||
|
||||
<ul id="elb_faq_0024__en-us_topic_0044589572_ul39655260125151"><li id="elb_faq_0024__en-us_topic_0044589572_li21353022125151">UDP health checks use ping packets to detect the health of the backend <span id="elb_faq_0024__text4243511499722">server</span>. To ensure smooth transmission of these packets, ensure that ICMP is enabled on the backend <span id="elb_faq_0024__text9486641229734">server</span> by performing the following:<p id="elb_faq_0024__en-us_topic_0044589572_p57959472125151">Log in to the <span id="elb_faq_0024__text2377681409836">server</span> and run the following command as user <strong id="elb_faq_0024__b8423527069814">root</strong>:</p>
|
||||
<p id="elb_faq_0024__en-us_topic_0044589572_p51873203125151"><strong id="elb_faq_0024__en-us_topic_0044589572_b65813485141827">cat /proc/sys/net/ipv4/icmp_echo_ignore_all</strong></p>
|
||||
<ul id="elb_faq_0024__ul5991332115413"><li id="elb_faq_0024__li5383645415427">If the returned value is <strong id="elb_faq_0024__b2702449915427">1</strong>, ICMP is disabled.</li><li id="elb_faq_0024__li234898115413">If the returned value is <strong id="elb_faq_0024__b46864838191253">0</strong>, ICMP is enabled.</li></ul>
|
||||
</li><li id="elb_faq_0024__en-us_topic_0044589572_li33275046125151">The health check result may be different from the actual health of the backend server.<p id="elb_faq_0024__en-us_topic_0044589572_p31039959125151"><a name="elb_faq_0024__en-us_topic_0044589572_li33275046125151"></a><a name="en-us_topic_0044589572_li33275046125151"></a>If the backend server runs a Linux OS, the rate of ICMP packets is limited due to protection from ICMP floods of Linux when there is a large number of concurrent requests. In this case, if a service exception occurs, the load balancer will not receive error message <strong id="elb_faq_0024__b84235270615853">port XX unreachable</strong> and will still determine that the health check is successful. As a result, there is an inconsistency between the health check result and the actual server health.</p>
|
||||
</li><li id="elb_faq_0024__en-us_topic_0044589572_li810919912528">UDP listeners cannot be added to a private network classic load balancer.<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_faq_0024__p1129116891613">Classic load balancers can no longer be created on the management console.</p>
|
||||
</div>
|
||||
</li></ul>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0204.html">Health Check</a>
|
||||
|
||||
|
||||
|
||||
@ -1,13 +0,0 @@
|
||||
<a name="elb_faq_0038"></a><a name="elb_faq_0038"></a>
|
||||
|
||||
<h1 class="topictitle1">How Does ELB Distribute Traffic?</h1>
|
||||
<p id="elb_faq_0038__en-us_topic_0100578533_p42330367111657">ELB uses FullNAT to forward the incoming traffic. For load balancing at Layer 4, LVS forwards the incoming traffic to backend servers directly. For load balancing at Layer 7, LVS forwards the incoming traffic to Nginx, which then forwards the traffic to backend servers.</p>
|
||||
<span class="figcap"><b>Figure 1 </b>Load balancing at Layer 4</span><br><span><img id="elb_faq_0038__en-us_topic_0100578533_image49893921173712" src="en-us_image_0168438373.jpg"></span>
|
||||
<span class="figcap"><b>Figure 2 </b>Load balancing at Layer 7</span><br><span><img id="elb_faq_0038__en-us_topic_0100578533_image32360488173922" src="en-us_image_0168438378.jpg"></span>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0201.html">Load Balancer</a>
|
||||
|
||||
|
||||
|
||||
@ -1,15 +0,0 @@
|
||||
<a name="elb_faq_0039"></a><a name="elb_faq_0039"></a>
|
||||
|
||||
<h1 class="topictitle1">How Do I Check the Network Conditions of a Backend Server?</h1>
|
||||
<ol id="elb_faq_0039__en-us_topic_0100578534_ol43143701174341"><li id="elb_faq_0039__en-us_topic_0100578534_li62098667174341">Verify that an IP address has been assigned to the server's primary NIC.<ol type="a" id="elb_faq_0039__en-us_topic_0100578534_ol58104270174422"><li id="elb_faq_0039__en-us_topic_0100578534_li26117718174419">Log in to the server. (An ECS is used as an example here.)</li><li id="elb_faq_0039__en-us_topic_0100578534_li63468792174419">Run the <strong id="elb_faq_0039__en-us_topic_0100578534_b84235270614498">ifconfig</strong> or <strong id="elb_faq_0039__en-us_topic_0100578534_b842352706144912">ip address</strong> command to view the IP address.<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_faq_0039__en-us_topic_0100578534_p40184371174333">For Windows ECSs, run <strong id="elb_faq_0039__en-us_topic_0100578534_b842352706145011">ipconfig</strong> on the CLI to view their IP addresses.</p>
|
||||
</div>
|
||||
</li></ol>
|
||||
</li><li id="elb_faq_0039__en-us_topic_0100578534_li44262848174829">Ping the gateway of the subnet where the ECS resides to check basic network communication.<ol type="a" id="elb_faq_0039__en-us_topic_0100578534_ol8442521174940"><li id="elb_faq_0039__en-us_topic_0100578534_li44715074174835">On the VPC details page, locate the subnet and view the gateway address in the <strong id="elb_faq_0039__b136011758174">Gateway</strong> column. Generally, the gateway address ends with <strong id="elb_faq_0039__b17295732101712">.1</strong>.</li><li id="elb_faq_0039__en-us_topic_0100578534_li234301174759">Ping the gateway from the ECS. If the gateway cannot be pinged, check the networks at Layer 2 and Layer 3.</li></ol>
|
||||
</li></ol>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0203.html">Backend Server</a>
|
||||
|
||||
|
||||
|
||||
@ -1,13 +0,0 @@
|
||||
<a name="elb_faq_0040"></a><a name="elb_faq_0040"></a>
|
||||
|
||||
<h1 class="topictitle1">How Do I Check the Network Configuration of a Backend Server?</h1>
|
||||
<ol id="elb_faq_0040__en-us_topic_0100578555_ol51835414175346"><li id="elb_faq_0040__en-us_topic_0100578555_li26028006175346">Check whether the security group of the server is correctly configured.<ol type="a" id="elb_faq_0040__en-us_topic_0100578555_ol15120255104222"><li id="elb_faq_0040__en-us_topic_0100578555_li8965360104233">On the server details page, view the security group.</li><li id="elb_faq_0040__en-us_topic_0100578555_li1578311018">Check whether the security group allows access from IP addresses in 100.125.0.0/16<span id="elb_faq_0040__ph1820812303110"></span>. If access is not allowed, add inbound rules for 100.125.0.0/16<span id="elb_faq_0040__ph587815491446"></span>.</li></ol>
|
||||
</li><li id="elb_faq_0040__en-us_topic_0100578555_li2154564893111">Ensure that the network ACLs of the subnet where the server resides does not intercept the traffic.<p id="elb_faq_0040__en-us_topic_0100578555_p2017488793128"><a name="elb_faq_0040__en-us_topic_0100578555_li2154564893111"></a><a name="en-us_topic_0100578555_li2154564893111"></a>In the left navigation pane on the VPC console, choose <strong id="elb_faq_0040__b855515395272">Access Control</strong>> <strong id="elb_faq_0040__b13265597275">Network ACLs</strong> and check whether the subnet allows traffic.</p>
|
||||
</li></ol>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0203.html">Backend Server</a>
|
||||
|
||||
|
||||
|
||||
@ -1,18 +0,0 @@
|
||||
<a name="elb_faq_0041"></a><a name="elb_faq_0041"></a>
|
||||
|
||||
<h1 class="topictitle1">How Do I Check the Status of a Backend Server?</h1>
|
||||
<ol id="elb_faq_0041__en-us_topic_0101328255_ol2879999611816"><li id="elb_faq_0041__en-us_topic_0101328255_li6248705311816">Verify that the applications on the backend server are enabled.<ol type="a" id="elb_faq_0041__en-us_topic_0101328255_ol4122204711912"><li id="elb_faq_0041__en-us_topic_0101328255_li6552894411916">Log in to the backend server. (An ECS is used as an example here.)</li><li id="elb_faq_0041__en-us_topic_0101328255_li3517118211943">Run the following command to check the port status:<p id="elb_faq_0041__en-us_topic_0101328255_p568284811944"><a name="elb_faq_0041__en-us_topic_0101328255_li3517118211943"></a><a name="en-us_topic_0101328255_li3517118211943"></a><strong id="elb_faq_0041__en-us_topic_0101328255_b420613211943">netstat -ntpl</strong></p>
|
||||
<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span>For Windows ECSs, run the <strong id="elb_faq_0041__en-us_topic_0101328255_b842352706152848">netstat -ano</strong> command on the CLI to view the port status or server software status.<span class="figcap"><b>Figure 1 </b>Port status</span><br><span><img id="elb_faq_0041__en-us_topic_0101328255_image1606983511124" src="en-us_image_0168612036.jpg"></span>
|
||||
|
||||
</div>
|
||||
</li></ol>
|
||||
</li><li id="elb_faq_0041__en-us_topic_0101328255_li16052523112231">Check the network communication of the ECS.<p id="elb_faq_0041__en-us_topic_0101328255_p12721331114814"><a name="elb_faq_0041__en-us_topic_0101328255_li16052523112231"></a><a name="en-us_topic_0101328255_li16052523112231"></a>For example, if the ECS uses port 80, run the <strong id="elb_faq_0041__en-us_topic_0101328255_b842352706153210">curl</strong> command to check whether the communication is normal.</p>
|
||||
<p id="elb_faq_0041__p1711753185312"><span><img id="elb_faq_0041__image1711753125311" src="en-us_image_0238256358.jpg"></span></p>
|
||||
</li></ol>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0203.html">Backend Server</a>
|
||||
|
||||
|
||||
|
||||
@ -1,11 +0,0 @@
|
||||
<a name="elb_faq_0046"></a><a name="elb_faq_0046"></a>
|
||||
|
||||
<h1 class="topictitle1">How Do I Check If Sticky Sessions Fail to Take Effect?</h1>
|
||||
<ol id="elb_faq_0046__ol627910268405"><li id="elb_faq_0046__li0279112615402">Check whether sticky sessions are enabled for the backend server group. If sticky sessions are enabled, go to the next step.</li><li id="elb_faq_0046__li327913260407">Check the health check result of the backend server. If the health check result is <strong id="elb_faq_0046__b579774331811">Unhealthy</strong>, traffic is routed to other backend servers and sticky sessions become invalid.</li><li id="elb_faq_0046__li1727982616408">If you select the source IP hash algorithm, check whether the IP address of the request changes before the load balancer receives the request.</li><li id="elb_faq_0046__li122791326124013">If an HTTP or HTTPS listener is configured with sticky sessions enabled, check whether the request carries a cookie. If yes, check whether the cookie value changes (because load balancing at Layer 7 uses cookies to maintain sessions).</li></ol>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0190.html">Sticky Session</a>
|
||||
|
||||
|
||||
|
||||
@ -1,11 +0,0 @@
|
||||
<a name="elb_faq_0049"></a><a name="elb_faq_0049"></a>
|
||||
|
||||
<h1 class="topictitle1">How Do I Check Traffic Inconsistency?</h1>
|
||||
<p id="elb_faq_0049__p1693782873219">Check for failed requests on the clients, especially when <em id="elb_faq_0049__i842352697102856">4xx</em> status codes are returned. A possible cause is that the requests are rejected by ELB and are not routed to backend servers because ELB considers these requests abnormal.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0127.html">Service Performance and Load</a>
|
||||
|
||||
|
||||
|
||||
@ -1,13 +0,0 @@
|
||||
<a name="elb_faq_0050"></a><a name="elb_faq_0050"></a>
|
||||
|
||||
<h1 class="topictitle1">How Do I Check If Traffic Is Evenly Distributed?</h1>
|
||||
<ol id="elb_faq_0050__ol7137172232919"><li id="elb_faq_0050__li31371522152912">Check whether sticky sessions are enabled. If sticky sessions are enabled and there are few clients, traffic may be unevenly distributed.</li><li id="elb_faq_0050__li1113872252910">Check the health of backend servers, especially those whose health changes over time. If the health check result is <strong id="elb_faq_0050__b84235270612021">Unhealthy</strong> or switches between <strong id="elb_faq_0050__b62279156712054">Healthy</strong> and <strong id="elb_faq_0050__b196399472312054">Unhealthy</strong>, traffic is unbalanced.</li><li id="elb_faq_0050__li15138222122920">Check whether the <strong id="elb_faq_0050__b84235270614950">Source IP hash</strong> algorithm is used. If the algorithm is used, requests sent from the same IP address are routed to the same backend server, resulting in unbalanced traffic.</li><li id="elb_faq_0050__li513814222293">Check whether applications on the backend server use keepalive to maintain TCP persistent connections. If keepalive is used, traffic may be unbalanced because the number of requests on persistent connections is different.</li><li id="elb_faq_0050__li18138522192914">Check whether different weights are assigned to backend servers. The traffic varies according to the weights.</li></ol>
|
||||
<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_faq_0050__p66213356328">Generally, in addition to the load balancing algorithm, factors that affect load balancing include connection type, session stickiness, and server weights.</p>
|
||||
</div>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0127.html">Service Performance and Load</a>
|
||||
|
||||
|
||||
|
||||
@ -1,11 +0,0 @@
|
||||
<a name="elb_faq_0052"></a><a name="elb_faq_0052"></a>
|
||||
|
||||
<h1 class="topictitle1">What Do I Do If a Load Balancer Fails the Stress Test?</h1>
|
||||
<ol id="elb_faq_0052__ol140474553419"><li id="elb_faq_0052__li640464543416">Check the load of backend servers. If their CPU usage reaches 100%, applications may have performance bottlenecks.</li><li id="elb_faq_0052__li1640419457346">Check the incoming traffic. If the incoming traffic exceeds the maximum bandwidth set for the EIP, a large number of packets will be lost and requests will not be responded to, thereby affecting the load balancer's performance.</li><li id="elb_faq_0052__li791993451610">Check the number of short connections in the <strong id="elb_faq_0052__b1531518182445">time_wait</strong> state on the clients. A possible cause is that there are insufficient client ports.</li><li id="elb_faq_0052__li1140474503412">The listening queue backlog of the backend servers is full. As a result, the backend server does not respond to SYN ACK packets, and the client times out. You can increase the upper limit of the backlog by adjusting the <strong id="elb_faq_0052__b8423527061595">net.core.somaxconn</strong> parameter.</li></ol>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0127.html">Service Performance and Load</a>
|
||||
|
||||
|
||||
|
||||
@ -1,12 +0,0 @@
|
||||
<a name="elb_faq_0060"></a><a name="elb_faq_0060"></a>
|
||||
|
||||
<h1 class="topictitle1">Can ELB Be Used Separately?</h1>
|
||||
<p id="elb_faq_0060__p18255193114219">ELB cannot be used alone.</p>
|
||||
<p id="elb_faq_0060__p8060118">ELB is a service that distributes incoming traffic across servers and must be used with the ECS or BMS service.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0211.html">ELB Functionality</a>
|
||||
|
||||
|
||||
|
||||
@ -1,11 +0,0 @@
|
||||
<a name="elb_faq_0062"></a><a name="elb_faq_0062"></a>
|
||||
|
||||
<h1 class="topictitle1">Can I Adjust the Number of Backend Servers When a Load Balancer is Running?</h1>
|
||||
<p id="elb_faq_0062__p8060118">You can adjust the number of backend servers associated with a load balancer at any time. You can also change the type of backend servers according to your business needs. To ensure service stability, ensure that health checks are normal and that at least one healthy backend server is associated with the load balancer.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0211.html">ELB Functionality</a>
|
||||
|
||||
|
||||
|
||||
@ -1,12 +0,0 @@
|
||||
<a name="elb_faq_0064"></a><a name="elb_faq_0064"></a>
|
||||
|
||||
<h1 class="topictitle1">Can Backend Servers Run Different OSs?</h1>
|
||||
<p id="elb_faq_0064__p2957467704537">Yes.</p>
|
||||
<p id="elb_faq_0064__p6484550904537">ELB does not restrict OSs of backend servers as long as applications on these servers are the same and the data is consistent. However, it is recommended that you install the same OS on backend servers to simplify management.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0211.html">ELB Functionality</a>
|
||||
|
||||
|
||||
|
||||
@ -1,15 +0,0 @@
|
||||
<a name="elb_faq_0085"></a><a name="elb_faq_0085"></a>
|
||||
|
||||
<h1 class="topictitle1">What Types of Sticky Sessions Does ELB Support?</h1>
|
||||
<p id="elb_faq_0085__p8292617145212">Dedicated load balancers: <strong id="elb_faq_0085__b230520591448">Source IP address</strong> and <strong id="elb_faq_0085__b1131715911446">Load balancer cookie</strong></p>
|
||||
<p id="elb_faq_0085__p528462741203"><span id="elb_faq_0085__ph15170164618279">Shared</span> load balancers: <strong id="elb_faq_0085__b3335228194515">Source IP address</strong>, <strong id="elb_faq_0085__b333113404510">Load balancer cookie</strong>, and <strong id="elb_faq_0085__b910418384459">Application cookie</strong></p>
|
||||
<p id="elb_faq_0085__p8346956175115">Classic load balancers: <strong id="elb_faq_0085__b353211205466">Source IP address</strong> and <strong id="elb_faq_0085__b208024154612">Load balancer cookie</strong></p>
|
||||
<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_faq_0085__p1129116891613">Classic load balancers can no longer be created on the management console.</p>
|
||||
</div>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0190.html">Sticky Session</a>
|
||||
|
||||
|
||||
|
||||
@ -1,81 +0,0 @@
|
||||
<a name="elb_faq_0090"></a><a name="elb_faq_0090"></a>
|
||||
|
||||
<h1 class="topictitle1">How Can I Obtain the IP Address of a Client?</h1>
|
||||
<p id="elb_faq_0090__p126130261229">When you use ELB to route requests to backend servers, IP addresses of the clients will be translated by the ELB system. This FAQ provides the operations for obtaining the IP addresses of the clients.</p>
|
||||
<h4 class="sectiontitle">Constraints and Limitations</h4><ul id="elb_faq_0090__ul104521513161519"><li id="elb_faq_0090__li13452113161512">If Network Address Translation (NAT) or Web Application Firewall (WAF) is used, you cannot obtain the IP addresses of the clients.</li><li id="elb_faq_0090__li9274171501517">If the client is a container, you can obtain only the IP address of the node where the container is located, but cannot obtain the IP address of the container.</li><li id="elb_faq_0090__li9335359112219">If the <strong id="elb_faq_0090__b352118212323">Obtain Client IP Address</strong> option is enabled for TCP or UDP listeners, a cloud server cannot be used as a backend server and a client at the same time. In this case, you can configure the TOA plug-in to obtain the source IP addresses.</li><li id="elb_faq_0090__li983412419371">By default, the <strong id="elb_faq_0090__b149753488323">Obtain Client IP Address</strong> option is enabled for TCP and UDP listeners of dedicated load balancers. You do not need to manually enable it.</li></ul>
|
||||
|
||||
<h4 class="sectiontitle">Layer 7 Load Balancing</h4><p id="elb_faq_0090__p1023417204310">Configure the application server and obtain the IP address of a client from the HTTP header.</p>
|
||||
|
||||
<p id="elb_faq_0090__p831417121548">The real IP address is placed in the X-Forwarded-For header field by the load balancer in the following format:</p>
|
||||
<pre class="screen" id="elb_faq_0090__screen1187691785410">X-Forwarded-For: <em id="elb_faq_0090__i1750233911017">IP address of the client</em>,<em id="elb_faq_0090__i1750311398014">Proxy server 1-IP address</em>,<em id="elb_faq_0090__i5504183920016">Proxy server 2-IP address</em>,...</pre>
|
||||
<p id="elb_faq_0090__p20617125125319">If you use this method, the first IP address obtained is the IP address of the client.</p>
|
||||
<p id="elb_faq_0090__p19756101917416"><strong id="elb_faq_0090__b10993195705216">Apache Server</strong></p>
|
||||
<ol id="elb_faq_0090__ol6308148164116"><li id="elb_faq_0090__li12308194814416">Install Apache 2.4.<p id="elb_faq_0090__p730884864117"><a name="elb_faq_0090__li12308194814416"></a><a name="li12308194814416"></a>For example, if CentOS 7.5 is used as the OS, run the following command to install the software:</p>
|
||||
<pre class="screen" id="elb_faq_0090__screen179405819412">yum install httpd</pre>
|
||||
</li><li id="elb_faq_0090__li119211618194213">Add the following content to the end of Apache configuration file <strong id="elb_faq_0090__b17513185075513">/etc/httpd/conf/httpd.conf</strong>:<pre class="screen" id="elb_faq_0090__screen777611144433">LoadModule remoteip_module modules/mod_remoteip.so
|
||||
RemoteIPHeader X-Forwarded-For
|
||||
RemoteIPInternalProxy <strong id="elb_faq_0090__b1977615149432"><em id="elb_faq_0090__i1777601412436">100.125.0.0/16</em></strong></pre>
|
||||
<span class="figcap"><b>Figure 1 </b>Content to be added</span><br><span><img id="elb_faq_0090__image1368125117439" src="en-us_image_0174899056.jpg"></span>
|
||||
<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_faq_0090__p11969135614319">Add the IP address range of the proxy server after <strong id="elb_faq_0090__b110010178155">RemoteIPInternalProxy</strong>.</p>
|
||||
<ul id="elb_faq_0090__ul5985165818319"><li id="elb_faq_0090__li49865581436"><span id="elb_faq_0090__ph1911810238">Shared</span> load balancers: 100.125.0.0/16<span id="elb_faq_0090__ph1820812303110"></span> and the IP address range used by the AAD service. 100.125.0.0/16 is used by load balancers to communicate with backend servers, and there are no security risks. Use commas (,) to separate multiple entries.</li><li id="elb_faq_0090__li6194337848">Dedicated load balancers: the CIDR block of the subnet where the load balancer resides</li></ul>
|
||||
</div>
|
||||
</li><li id="elb_faq_0090__li10895421174213">Change the log output format in the Apache configuration file to the following (<strong id="elb_faq_0090__b1311681216319">%a</strong> indicates the source IP address):<pre class="screen" id="elb_faq_0090__screen13565739124411">LogFormat "<em id="elb_faq_0090__i18199122934118"><strong id="elb_faq_0090__b5762132774111">%</strong><strong id="elb_faq_0090__b194131533162710">a</strong></em> %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined</pre>
|
||||
</li><li id="elb_faq_0090__li1851619394515">Restart Apache.<pre class="screen" id="elb_faq_0090__screen108061723195117">systemctl restart httpd</pre>
|
||||
</li><li id="elb_faq_0090__li156661737145114">Obtain the actual IP address of the client from the httpd access logs.</li></ol>
|
||||
<p id="elb_faq_0090__p6714439135314"><strong id="elb_faq_0090__b577241918535">Nginx Server</strong></p>
|
||||
<p id="elb_faq_0090__p155321736613">For example, if CentOS 7.5 is used as the OS, run the following command to install the software:</p>
|
||||
<ol id="elb_faq_0090__ol7358205916533"><li id="elb_faq_0090__li0358155914534">Run the following commands to install http_realip_module:<pre class="screen" id="elb_faq_0090__screen1882810131546">yum -y install gcc pcre pcre-devel zlib zlib-devel openssl openssl-devel
|
||||
wget http://nginx.org/download/nginx-1.17.0.tar.gz
|
||||
tar zxvf nginx-1.17.0.tar.gz
|
||||
cd nginx-1.17.0
|
||||
./configure --prefix=/path/server/nginx --with-http_stub_status_module --without-http-cache --with-http_ssl_module --with-http_realip_module
|
||||
make
|
||||
make install</pre>
|
||||
</li><li id="elb_faq_0090__li157133719579">Run the following command to open the <strong id="elb_faq_0090__b284014426589">nginx.conf</strong> file:<pre class="screen" id="elb_faq_0090__screen168161722125710">vi /path/server/nginx/conf/nginx.conf</pre>
|
||||
</li><li id="elb_faq_0090__li08471939155717">Add the following content under <strong id="elb_faq_0090__b749741615367">http</strong> or <strong id="elb_faq_0090__b182411020113613">server</strong>:<pre class="screen" id="elb_faq_0090__screen114715217570">;<em id="elb_faq_0090__i486310577577"><strong id="elb_faq_0090__b3978993586">100.125.0.0/16</strong></em>set_real_ip_from
|
||||
real_ip_header X-Forwarded-For;</pre>
|
||||
<span class="figcap"><b>Figure 2 </b>Content to be added</span><br><span><img id="elb_faq_0090__image117512241589" src="en-us_image_0174914269.jpg"></span>
|
||||
<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_faq_0090__p66517423613">Add the IP address range of the proxy server after <strong id="elb_faq_0090__b115641940173910">set_real_ip_from</strong>.</p>
|
||||
<ul id="elb_faq_0090__ul382910413719"><li id="elb_faq_0090__li13829341171"><span id="elb_faq_0090__ph17309135819617">Shared</span> load balancers: 100.125.0.0/16<span id="elb_faq_0090__ph5282205074611"></span> and the IP address range used by the AAD service. (100.125.0.0/16 is used by load balancers to communicate with backend servers, and there are no security risks. Use commas to separate multiple entries.</li></ul>
|
||||
<ul id="elb_faq_0090__ul410015111674"><li id="elb_faq_0090__li14373314679">Dedicated load balancers: the CIDR block of the subnet where the load balancer resides</li></ul>
|
||||
</div>
|
||||
</li><li id="elb_faq_0090__li641018965916">Start Nginx.<pre class="screen" id="elb_faq_0090__screen578563035916">/path/server/nginx/sbin/nginx</pre>
|
||||
</li><li id="elb_faq_0090__li148240105591">Obtain the actual IP address of the client from the Nginx access logs.<pre class="screen" id="elb_faq_0090__screen8367134511812">cat /path/server/nginx/logs/access.log</pre>
|
||||
</li></ol>
|
||||
<p id="elb_faq_0090__p480771725215"><strong id="elb_faq_0090__b16433239142610">Tomcat Servers</strong></p>
|
||||
<p id="elb_faq_0090__p1680781711526">In the following operations, the Tomcat installation path is <strong id="elb_faq_0090__b944410301920">/usr/tomcat/tomcat8/</strong>.</p>
|
||||
<ol id="elb_faq_0090__ol78072171526"><li id="elb_faq_0090__li2497621114416">Log in to a server on which Tomcat is installed.</li><li id="elb_faq_0090__li20249121115120">Check whether Tomcat is running properly.<pre class="screen" id="elb_faq_0090__screen44802295146">ps -ef|grep tomcat
|
||||
netstat -anpt|grep java</pre>
|
||||
<span class="figcap"><b>Figure 3 </b>Tomcat running properly</span><br><span><img id="elb_faq_0090__image12991039151611" src="en-us_image_0276143526.png"></span>
|
||||
</li><li id="elb_faq_0090__li19727103382213">Add the following configuration items to the <strong id="elb_faq_0090__b2106163312205">server.xml</strong> file:<pre class="screen" id="elb_faq_0090__screen1724114353318"><Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
|
||||
prefix="localhost_access_log." suffix=".txt"
|
||||
pattern="%{X-FORWARDED-FOR}i %l %u %t %r %s %b %D %q %{User-Agent}i %T" resolveHosts="false" /></pre>
|
||||
<span class="figcap"><b>Figure 4 </b>Example configuration</span><br><span><img id="elb_faq_0090__image465444415514" src="en-us_image_0276220702.png"></span>
|
||||
</li><li id="elb_faq_0090__li10807317205216">Restart the Tomcat service.<pre class="screen" id="elb_faq_0090__screen1289953143813">cd /usr/tomcat/tomcat8/bin && sh startup.sh</pre>
|
||||
<p id="elb_faq_0090__p7855124164517">In this command, <strong id="elb_faq_0090__b1160153111279">/usr/tomcat/tomcat8/</strong> is the Tomcat installation path. Change it based on site requirements.</p>
|
||||
<span class="figcap"><b>Figure 5 </b>Restarting the Tomcat service</span><br><span><img id="elb_faq_0090__image1537214114202" src="en-us_image_0276225173.png"></span>
|
||||
</li><li id="elb_faq_0090__li52307461589">View the latest logs.<p id="elb_faq_0090__p6782174619819"><a name="elb_faq_0090__li52307461589"></a><a name="li52307461589"></a>As highlighted in the following figure, IP addresses that are not in the IP address range starting with 100.125 are the source IP addresses.</p>
|
||||
<pre class="screen" id="elb_faq_0090__screen5699423179">cat localhost_access_log..2020-09-10.txt</pre>
|
||||
<p id="elb_faq_0090__p1499318356184">In this command, <strong id="elb_faq_0090__b1309101394310">localhost_access_log..2020-09-10.txt</strong> indicates the log path of the current day. Change it based on site requirements.</p>
|
||||
<span class="figcap"><b>Figure 6 </b>Querying the source IP address</span><br><span><img id="elb_faq_0090__image360791441717" src="en-us_image_0276223899.png"></span>
|
||||
</li></ol>
|
||||
<p id="elb_faq_0090__p16107922101012">Windows Server with IIS Deployed</p>
|
||||
<p id="elb_faq_0090__p68600531213">The following uses Windows Server 2012 with IIS7 as an example to describe how to obtain the source IP address.</p>
|
||||
<ol id="elb_faq_0090__ol610718229101"><li id="elb_faq_0090__li76432018259">Download and install IIS.</li><li id="elb_faq_0090__li91351915183019">Download the <strong id="elb_faq_0090__b14943951164816">F5XForwardedFor.dll</strong> plug-in and copy the plug-ins in the <strong id="elb_faq_0090__b622893114919">x86</strong> and <strong id="elb_faq_0090__b8309153684912">x64</strong> directories to a directory for which IIS has the access permission, for example, <strong id="elb_faq_0090__b1610019581407">C:\F5XForwardedFor2008</strong>.</li><li id="elb_faq_0090__li656010311115">Open the Server Manager and choose <strong id="elb_faq_0090__b71521450114319">Modules</strong> > <strong id="elb_faq_0090__b4123165611432">Configure Native Modules</strong>.<span class="figcap"><b>Figure 7 </b>Selecting modules</span><br><span><img id="elb_faq_0090__image555920581104" src="en-us_image_0267429969.png"></span>
|
||||
<span class="figcap"><b>Figure 8 </b>Configure Native Modules</span><br><span><img id="elb_faq_0090__image19181513320" src="en-us_image_0267431325.png"></span>
|
||||
</li><li id="elb_faq_0090__li158981131057">Click <strong id="elb_faq_0090__b10305101117465">Register</strong> to register the x86 and x64 plug-ins.<span class="figcap"><b>Figure 9 </b>Registering plug-ins</span><br><span><img id="elb_faq_0090__image8335241059" src="en-us_image_0267432483.png"></span>
|
||||
</li><li id="elb_faq_0090__li14440312814">In the <strong id="elb_faq_0090__b104651358134613">Modules</strong> dialog box, verify that the registered plug-ins are displayed in the list.<span class="figcap"><b>Figure 10 </b>Confirming the registration</span><br><span><img id="elb_faq_0090__image14574191416814" src="en-us_image_0267434399.png"></span>
|
||||
</li><li id="elb_faq_0090__li2088319001410">Select <strong id="elb_faq_0090__b1076244794818">ISAPI Filters</strong> on the Server Manager homepage and authorize two plug-ins to run ISAPI and CGI extensions.<span class="figcap"><b>Figure 11 </b>Adding authorization</span><br><span><img id="elb_faq_0090__image121471154181314" src="en-us_image_0267440227.png"></span>
|
||||
</li><li id="elb_faq_0090__li1522516511177">Select <strong id="elb_faq_0090__b97915442492">ISAPI and CGI Restriction</strong> to set the execution permission for the two plug-ins.<span class="figcap"><b>Figure 12 </b>Allowing the plug-ins to execute</span><br><span><img id="elb_faq_0090__image18752134415175" src="en-us_image_0267442311.png"></span>
|
||||
</li><li id="elb_faq_0090__li16707014261">Click <strong id="elb_faq_0090__b8679927125015">Restart</strong> on the homepage to restart IIS. The configuration will take effect after the restart.<span class="figcap"><b>Figure 13 </b>Restarting IIS</span><br><span><img id="elb_faq_0090__image8470105182515" src="en-us_image_0267446611.png"></span>
|
||||
</li></ol>
|
||||
<h4 class="sectiontitle">Layer 4 Load Balancing</h4><p id="elb_faq_0090__p9180141819616">TCP listeners require the TOA plug-in to obtain real IP addresses. For details, see <a href="en-us_elb_06_0001.html">Configuring the TOA Plug-in</a>.</p>
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0170.html">Obtaining Source IP Addresses</a>
|
||||
|
||||
|
||||
|
||||
@ -1,11 +0,0 @@
|
||||
<a name="elb_faq_0111"></a><a name="elb_faq_0111"></a>
|
||||
|
||||
<h1 class="topictitle1">How Can I Use WebSocket?</h1>
|
||||
<p id="elb_faq_0111__p8060118">For HTTP listeners, unencrypted WebSocket (ws://) is supported by default. For HTTPS listeners, encrypted WebSocket (wss://) is supported by default.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0202.html">Listener</a>
|
||||
|
||||
|
||||
|
||||
@ -1,12 +0,0 @@
|
||||
<a name="elb_faq_0112"></a><a name="elb_faq_0112"></a>
|
||||
|
||||
<h1 class="topictitle1">Why Is the Interval at Which Backend Servers Receive Health Check Packets Different from the Configured Health Check Interval?</h1>
|
||||
<p id="elb_faq_0112__p1294414571272">Each LVS node and Nginx node in the ELB system detect backend servers at the health check interval that you have specified for the backend server group.</p>
|
||||
<p id="elb_faq_0112__p8060118">During this period, backend servers receive multiple detection packets from LVS and Nginx nodes. This makes it seem that backend servers receive these packets at intervals shorter than the specified health check interval.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0203.html">Backend Server</a>
|
||||
|
||||
|
||||
|
||||
@ -1,11 +0,0 @@
|
||||
<a name="elb_faq_0114"></a><a name="elb_faq_0114"></a>
|
||||
|
||||
<h1 class="topictitle1">Why Does ELB Frequently Send Requests to Backend Servers During Health Checks?</h1>
|
||||
<p id="elb_faq_0114__p089414334718">ELB is deployed in cluster mode, and all nodes for request forwarding in the cluster send requests to backend servers at the same time. If the health check interval is too short, health checks are performed once every few seconds, and a large number of packets are sent to backend servers. To control the frequency of access to backend servers, change the health check interval by referring to <a href="en-us_topic_0162227063.html">Configuring a Health Check</a>.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0204.html">Health Check</a>
|
||||
|
||||
|
||||
|
||||
@ -1,13 +0,0 @@
|
||||
<a name="elb_faq_0118"></a><a name="elb_faq_0118"></a>
|
||||
|
||||
<h1 class="topictitle1">Why Is the Security Warning Still Displayed After a Certificate Is Configured?</h1>
|
||||
<p id="elb_faq_0118__p157971251144618">The following may cause the system to display a message indicating that a certificate is insecure:</p>
|
||||
<ul id="elb_faq_0118__ul0569141813473"><li id="elb_faq_0118__li5871122364718">The domain name used by the certificate is different from the domain name accessed by users. (If this is the case, check the domain name used the certificate to ensure that the domain names are the same or create a self-signed certificate.)</li><li id="elb_faq_0118__li17569418164712">SNI is configured, but the specified domain name is different from the one used by the certificate.</li><li id="elb_faq_0118__li1163891134818">The domain name level is inconsistent with the certificate level.</li></ul>
|
||||
<p id="elb_faq_0118__p8060118">If the problem persists, run the <strong id="elb_faq_0118__b744514119112">curl</strong> <em id="elb_faq_0118__i12667151215118">Domain name</em> command to locate the fault based on the error information returned by the system.</p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0180.html">HTTP/HTTPS Listener</a>
|
||||
|
||||
|
||||
|
||||
@ -1,20 +0,0 @@
|
||||
<a name="elb_faq_0127"></a><a name="elb_faq_0127"></a>
|
||||
|
||||
<h1 class="topictitle1">Service Performance and Load</h1>
|
||||
<p id="elb_faq_0127__p8060118"></p>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0049.html">How Do I Check Traffic Inconsistency?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0050.html">How Do I Check If Traffic Is Evenly Distributed?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0052.html">What Do I Do If a Load Balancer Fails the Stress Test?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0212.html">ELB Use</a>
|
||||
|
||||
|
||||
|
||||
@ -1,19 +0,0 @@
|
||||
<a name="elb_faq_0170"></a><a name="elb_faq_0170"></a>
|
||||
|
||||
|
||||
<h1 class="topictitle1">Obtaining Source IP Addresses</h1>
|
||||
|
||||
<p id="elb_faq_0170__p8060118"></p>
|
||||
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0090.html">How Can I Obtain the IP Address of a Client?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,16 +0,0 @@
|
||||
<a name="elb_faq_0180"></a><a name="elb_faq_0180"></a>
|
||||
|
||||
<h1 class="topictitle1">HTTP/HTTPS Listener</h1>
|
||||
<p id="elb_faq_0180__p8060118"></p>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0118.html">Why Is the Security Warning Still Displayed After a Certificate Is Configured?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,21 +0,0 @@
|
||||
<a name="elb_faq_0190"></a><a name="elb_faq_0190"></a>
|
||||
|
||||
|
||||
<h1 class="topictitle1">Sticky Session</h1>
|
||||
|
||||
<p id="elb_faq_0190__p8060118"></p>
|
||||
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0046.html">How Do I Check If Sticky Sessions Fail to Take Effect?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0085.html">What Types of Sticky Sessions Does ELB Support?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,11 +0,0 @@
|
||||
<a name="elb_faq_0200"></a><a name="elb_faq_0200"></a>
|
||||
|
||||
<h1 class="topictitle1">Popular Questions</h1>
|
||||
<ul id="elb_faq_0200__ul206931331103214"><li id="elb_faq_0200__li669312314327"><a href="elb_faq_0090.html">How Can I Obtain the IP Address of a Client?</a></li><li id="elb_faq_0200__li11561850133210"><a href="en-us_topic_0018127975.html">How Do I Troubleshoot an Unhealthy Backend Server?</a></li><li id="elb_faq_0200__li1176130193315"><a href="elb_faq_0024.html">How Does ELB Perform UDP Health Checks? What Are the Precautions for UDP Health Checks?</a></li><li id="elb_faq_0200__li31438516331"><a href="elb_faq_0085.html">What Types of Sticky Sessions Does ELB Support?</a></li><li id="elb_faq_0200__li1385051016337"><a href="elb_faq_0111.html">How Can I Use WebSocket?</a></li><li id="elb_faq_0200__li911814137339"><a href="elb_faq_0046.html">How Do I Check If Sticky Sessions Fail to Take Effect?</a></li><li id="elb_faq_0200__li1077718234335"><a href="en-us_elb_05_0008.html">What Are the Relationships Between Load Balancing Algorithms and Sticky Session Types?</a></li><li id="elb_faq_0200__li191851335103319"><a href="elb_faq_0038.html">How Does ELB Distribute Traffic?</a></li></ul>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,15 +0,0 @@
|
||||
<a name="elb_faq_0201"></a><a name="elb_faq_0201"></a>
|
||||
|
||||
<h1 class="topictitle1">Load Balancer</h1>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0038.html">How Does ELB Distribute Traffic?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,17 +0,0 @@
|
||||
<a name="elb_faq_0202"></a><a name="elb_faq_0202"></a>
|
||||
|
||||
<h1 class="topictitle1">Listener</h1>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="en-us_elb_05_0008.html">What Are the Relationships Between Load Balancing Algorithms and Sticky Session Types?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0111.html">How Can I Use WebSocket?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,25 +0,0 @@
|
||||
<a name="elb_faq_0203"></a><a name="elb_faq_0203"></a>
|
||||
|
||||
<h1 class="topictitle1">Backend Server</h1>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0112.html">Why Is the Interval at Which Backend Servers Receive Health Check Packets Different from the Configured Health Check Interval?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_099.html">Can Backend Servers Access the Internet After They Are Associated with a Load Balancer?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0039.html">How Do I Check the Network Conditions of a Backend Server?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0040.html">How Do I Check the Network Configuration of a Backend Server?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0041.html">How Do I Check the Status of a Backend Server?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0001.html">When Is a Backend Server Considered Healthy?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,19 +0,0 @@
|
||||
<a name="elb_faq_0204"></a><a name="elb_faq_0204"></a>
|
||||
|
||||
<h1 class="topictitle1">Health Check</h1>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="en-us_topic_0018127975.html">How Do I Troubleshoot an Unhealthy Backend Server?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0024.html">How Does ELB Perform UDP Health Checks? What Are the Precautions for UDP Health Checks?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0114.html">Why Does ELB Frequently Send Requests to Backend Servers During Health Checks?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,23 +0,0 @@
|
||||
<a name="elb_faq_0211"></a><a name="elb_faq_0211"></a>
|
||||
|
||||
<h1 class="topictitle1">ELB Functionality</h1>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0060.html">Can ELB Be Used Separately?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="en-us_elb_05_0011.html">Is an EIP Exclusively Assigned to a Load Balancer?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="en-us_elb_05_0004.html">How Many Load Balancers and Listeners Can I Have?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0062.html">Can I Adjust the Number of Backend Servers When a Load Balancer is Running?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0064.html">Can Backend Servers Run Different OSs?</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0212.html">ELB Use</a>
|
||||
|
||||
|
||||
|
||||
@ -1,18 +0,0 @@
|
||||
<a name="elb_faq_0212"></a><a name="elb_faq_0212"></a>
|
||||
|
||||
<h1 class="topictitle1">ELB Use</h1>
|
||||
<p id="elb_faq_0212__p8060118"></p>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0211.html">ELB Functionality</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_faq_0127.html">Service Performance and Load</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0000.html">FAQs</a>
|
||||
|
||||
|
||||
|
||||
@ -1,12 +0,0 @@
|
||||
<a name="elb_faq_099"></a><a name="elb_faq_099"></a>
|
||||
|
||||
<h1 class="topictitle1">Can Backend Servers Access the Internet After They Are Associated with a Load Balancer?</h1>
|
||||
<p id="elb_faq_099__p8060118">Yes. Backend servers can access the Internet whether or not they are associated with a load balancer.</p>
|
||||
<p id="elb_faq_099__p197711752182818"></p>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_faq_0203.html">Backend Server</a>
|
||||
|
||||
|
||||
|
||||
File diff suppressed because it is too large
Load Diff
@ -1,31 +1,3 @@
|
||||
<a name="elb_pro_0000"></a><a name="elb_pro_0000"></a>
|
||||
|
||||
<h1 class="topictitle1">Service Overview</h1>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="en-us_topic_0015479966.html">What Is ELB?</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_pro_0005.html">Product Advantages</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_pro_0006.html">Application Scenarios</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="en-us_elb_01_0007.html">Differences Between Classic and Shared Load Balancers</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_pro_0004.html">Differences Between Dedicated and Shared Load Balancers</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="en-us_topic_0287737145.html">Specifications of Dedicated Load Balancers</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_pro_0003.html">How ELB Works</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="en-us_elb_01_0004.html">Load Balancing on a Public or Private Network</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_ug_fz_0003_01.html">Network Traffic Paths</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="en-us_topic_0195131496.html">Product Concepts</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="elb_pro_0008.html">Integration with Other Services</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
|
||||
@ -1,80 +0,0 @@
|
||||
<a name="elb_pro_0001"></a><a name="elb_pro_0001"></a>
|
||||
|
||||
<h1 class="topictitle1">Basic Concepts</h1>
|
||||
|
||||
<table cellpadding="4" cellspacing="0" summary="" id="elb_pro_0001__table17643195014453" frame="border" border="1" rules="all"><caption><b>Table 1 </b>Some concepts about ELB</caption><thead align="left"><tr id="elb_pro_0001__row1644350164511"><th align="left" class="cellrowborder" valign="top" width="18%" id="mcps1.3.1.2.3.1.1"><p id="elb_pro_0001__p864415064515">Term</p>
|
||||
</th>
|
||||
<th align="left" class="cellrowborder" valign="top" width="82%" id="mcps1.3.1.2.3.1.2"><p id="elb_pro_0001__p96442503458">Definition</p>
|
||||
</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody><tr id="elb_pro_0001__row864475011450"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p4644135024515">Load balancer</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p3644250144511">A load balancer distributes incoming traffic across backend servers.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row17644115034512"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p186441250134518">Listener</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p2644950114515">A listener listens on requests from clients and routes the requests to backend <span id="elb_pro_0001__text64561152173613">server</span>s based on the settings that you configure when you add the listener.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row1364411502455"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p15644155084519">Backend server</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p1464425016457">A backend server is a cloud server added to a backend <span id="elb_pro_0001__elb_ug_hd_0001_text134779184156">server</span> group associated with a load balancer. When you add a listener to a load balancer, you can create or select a backend <span id="elb_pro_0001__elb_ug_hd_0001_text01565413152">server</span> group to receive requests from the load balancer by using the port and protocol you specify for the backend <span id="elb_pro_0001__elb_ug_hd_0001_text12774182671815">server</span> group and the load balancing algorithm you select.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row19644950204515"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p156441850134517">Backend server group</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p20644145034510">A backend server group is a collection of cloud servers that have same features. When you add a listener, you select a load balancing algorithm and create or select a backend server group. Incoming traffic is routed to the corresponding backend server group based on the listener's configuration.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row7644165084514"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p4644205015458">Health check</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p9644125014451">ELB periodically sends requests to backend <span id="elb_pro_0001__elb_ug_hc_0001_text174345265419">server</span>s to check whether they can process requests. If a backend <span id="elb_pro_0001__elb_ug_hc_0001_text442602317545">server</span> is detected as unhealthy, the load balancer stops routing requests to it. After the backend <span id="elb_pro_0001__elb_ug_hc_0001_text854154645414">server</span> recovers, the load balancer will resume routing requests to it.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row20644450204518"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p1964418505454">Redirect</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p5644135015457">HTTPS is an extension of HTTP. HTTPS encrypts data between a web server and a browser.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row364405094516"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p5462101841813">Sticky session</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p1564418504452">Sticky sessions ensure that requests from a client always get routed to the same backend server before a session elapses.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row564410505454"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p7644750164517">WebSocket</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p17963155112120">WebSocket is a new HTML5 protocol that provides full-duplex communication between the browser and the server. WebSocket saves server resources and bandwidth, and enables real-time communication. Both WebSocket and HTTP depend on TCP to transmit data. A handshake connection is required between the browser and server, so that they can communicate with each other only after the connection is established. However, as a bidirectional communication protocol, WebSocket is different from HTTP. After the handshake succeeds, both the server and browser (or client agent) can actively send data to or receive data from each other.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row3644145013456"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p064585018451">SNI</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p564595064516">SNI is an extension to TLS and enables a server to present multiple certificates on the same IP address and TCP port number. This allows multiple secure (HTTPS) websites (or any other service over TLS) to be served by the same IP address without requiring all websites to use the same certificate. SNI allows the client to submit the domain name information while sending an SSL handshake request. Once the load balancer receives the request, it queries the right certificate based on the domain name and returns the corresponding certificate to the client. If no certificate is found, the load balancer will return a default certificate.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row1264545054512"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p1764525015454">Persistent connection</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p96451550104515">A persistent connection allows multiple data packets to be sent continuously over a TCP connection. If no data packet is sent during the connection, the client and server send link detection packets to each other to maintain the connection.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row46458501457"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p26451050184518">Short connection</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p15645125017455">A short connection is a connection established when data is exchanged between the client and server and immediately closed after the data is sent.</p>
|
||||
</td>
|
||||
</tr>
|
||||
<tr id="elb_pro_0001__row91101346807"><td class="cellrowborder" valign="top" width="18%" headers="mcps1.3.1.2.3.1.1 "><p id="elb_pro_0001__p1811116467011">Concurrent connection</p>
|
||||
</td>
|
||||
<td class="cellrowborder" valign="top" width="82%" headers="mcps1.3.1.2.3.1.2 "><p id="elb_pro_0001__p7111134616018">Concurrent connections are total number of TCP connections initiated by clients and routed to backend servers by a load balancer per second.</p>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="en-us_topic_0195131496.html">Product Concepts</a>
|
||||
|
||||
|
||||
|
||||
@ -1,22 +0,0 @@
|
||||
<a name="elb_pro_0002"></a><a name="elb_pro_0002"></a>
|
||||
|
||||
<h1 class="topictitle1">Region and AZ</h1>
|
||||
<h4 class="sectiontitle">Concept</h4><p id="elb_pro_0002__en-us_topic_0184026189_p212716216381">A region and availability zone (AZ) identify the location of a data center. You can create resources in a specific region and AZ.</p>
|
||||
<ul id="elb_pro_0002__en-us_topic_0184026189_ul86578533460"><li id="elb_pro_0002__en-us_topic_0184026189_li14657175334618">A region is a physical data center, which is completely isolated to improve fault tolerance and stability. The region that is selected during resource creation cannot be changed after the resource is created.</li><li id="elb_pro_0002__en-us_topic_0184026189_li45875020473">An AZ is a physical location where resources use independent power supplies and networks. A region contains one or more AZs that are physically isolated but interconnected through internal networks. Because AZs are isolated from each other, any fault that occurs in one AZ will not affect others.</li></ul>
|
||||
<p id="elb_pro_0002__en-us_topic_0184026189_p1479174514614"><a href="#elb_pro_0002__en-us_topic_0184026189_fig8747114281212">Figure 1</a> shows the relationship between regions and AZs.</p>
|
||||
<a name="elb_pro_0002__en-us_topic_0184026189_fig8747114281212"></a><a name="en-us_topic_0184026189_fig8747114281212"></a><span class="figcap"><b>Figure 1 </b>Regions and AZs</span><br><span><img class="vsd" id="elb_pro_0002__en-us_topic_0184026189_image12748194211128" src="en-us_image_0184026531.png"></span>
|
||||
|
||||
<h4 class="sectiontitle">Selecting a Region</h4><p id="elb_pro_0002__en-us_topic_0184026189_p68521454132212">Select a region closest to your target users for lower network latency and quick access.</p>
|
||||
|
||||
<h4 class="sectiontitle">Selecting an AZ</h4><p id="elb_pro_0002__en-us_topic_0184026189_p859161416717">When deploying resources, consider your applications' requirements on disaster recovery (DR) and network latency.</p>
|
||||
<ul id="elb_pro_0002__en-us_topic_0184026189_ul157203571473"><li id="elb_pro_0002__en-us_topic_0184026189_li7720175710711">For high DR capability, deploy resources in different AZs within the same region.</li><li id="elb_pro_0002__en-us_topic_0184026189_li109763595719">For lower network latency, deploy resources in the same AZ.</li></ul>
|
||||
|
||||
<h4 class="sectiontitle">Regions and Endpoints</h4><p id="elb_pro_0002__en-us_topic_0184026189_p361784821111">Before you use an API to call resources, specify its region and endpoint. For more details, see <a href="https://docs.otc.t-systems.com/en-us/endpoint/index.html" target="_blank" rel="noopener noreferrer">Regions and Endpoints</a>.</p>
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="en-us_topic_0195131496.html">Product Concepts</a>
|
||||
|
||||
|
||||
|
||||
@ -1,25 +0,0 @@
|
||||
<a name="elb_pro_0003"></a><a name="elb_pro_0003"></a>
|
||||
|
||||
<h1 class="topictitle1">How ELB Works</h1>
|
||||
<p id="elb_pro_0003__p511191615473">To balance the load of your applications, create a load balancer to receive requests from clients and route the requests to backend <span id="elb_pro_0003__text748892718455">server</span>s in one or more AZs. Add at least a listener to the load balancer and associate at least a backend server with it. The load balancing algorithm you select when you add the listener determines how requests are distributed.</p>
|
||||
<h4 class="sectiontitle">Load Balancing Algorithms</h4><p id="elb_pro_0003__p1829390191019"><span id="elb_pro_0003__en-us_topic_0236111231_ph17638109145919">Shared</span> load balancers and dedicated load balancers support the following load balancing algorithms:</p>
|
||||
<ul id="elb_pro_0003__ul62874421822"><li id="elb_pro_0003__li1728610427215">Weighted round robin: Requests are routed to different servers based on their weights, which indicate server processing performance. Backend servers with higher weights receive proportionately more requests, whereas equal-weighted servers receive the same number of requests. This algorithm is often used for short connections, such as HTTP connections.<p id="elb_pro_0003__p16438104524911"><a name="elb_pro_0003__li1728610427215"></a><a name="li1728610427215"></a>The following figure shows an example of how requests are distributed using the weighted round robin algorithm. Two backend <span id="elb_pro_0003__text1263703874517">server</span>s are in the same AZ and have the same weight, and each <span id="elb_pro_0003__text7688194514452">server</span> receives the same proportion of requests.</p>
|
||||
<span class="figcap"><b>Figure 1 </b>Traffic distribution using the weighted round robin algorithm</span><br><span><img id="elb_pro_0003__image173432046115015" src="en-us_image_0000001160373426.png"></span>
|
||||
</li><li id="elb_pro_0003__li06431114312">Weighted least connections: In addition to the weight assigned to each server, the number of connections processed by each backend server is also considered. Requests are routed to the server with the lowest connections-to-weight ratio. In addition to the number of connections, each server is assigned a weight based on its capacity. Requests are routed to the server with the lowest connections-to-weight ratio. This algorithm is often used for persistent connections, such as connections to a database.<p id="elb_pro_0003__p7925102765415"><a name="elb_pro_0003__li06431114312"></a><a name="li06431114312"></a>The following figure shows an example of how requests are distributed using the weighted least connections algorithm. Two backend servers are in the same AZ and have the same weight, 100 connections have been established with backend server 01, and 50 connections have been connected with backend server 02. New requests are preferentially routed to backend server 02.</p>
|
||||
<span class="figcap"><b>Figure 2 </b>Traffic distribution using the weighted least connections algorithm</span><br><span><img id="elb_pro_0003__image12716112911553" src="en-us_image_0000001160533378.png"></span>
|
||||
</li><li id="elb_pro_0003__li1028712421427">Source IP hash: The source IP address of each request is calculated using the consistent hashing algorithm to obtain a unique hashing key, and all backend servers are numbered. The generated key is used to allocate the client to a particular server. This allows requests from different clients to be routed based on source IP addresses and ensures that a client is directed to the same server that it was using previously. This algorithm works well for TCP connections of load balancers that do not use cookies.<p id="elb_pro_0003__p166892034185613"><a name="elb_pro_0003__li1028712421427"></a><a name="li1028712421427"></a>The following figure shows an example of how requests are distributed using the source IP hash algorithm. Two backend servers are in the same AZ and have the same weight. If backend server 01 has processed a request from IP address A, the load balancer will route new requests from IP address A to backend server 01.</p>
|
||||
<span class="figcap"><b>Figure 3 </b>Traffic distribution using the source IP hash algorithm</span><br><span><img id="elb_pro_0003__image1784771565717" src="en-us_image_0000001205974859.png"></span>
|
||||
</li></ul>
|
||||
|
||||
Classic load balancers support the following load balancing algorithms:<ul id="elb_pro_0003__ul19194772154934"><li id="elb_pro_0003__li5131817515586">Round robin: Requests are distributed sequentially, evenly across all servers. This algorithm is often used for short connections, such as HTTP connections.</li><li id="elb_pro_0003__li5921039715586">Least connections: Requests are preferentially routed to backend servers with the minimum number of active connections. This algorithm is often used for persistent connections, such as connections to a database.</li><li id="elb_pro_0003__li555002129">Source IP hash: The source IP address of each request is calculated using the consistent hashing algorithm to obtain a unique hashing key, and all backend servers are numbered. The generated key is used to allocate the client to a particular server. This allows requests from different clients to be routed based on source IP addresses and ensures that a client is directed to the same server that it was using previously. This algorithm works well for TCP connections of load balancers that do not use cookies.</li></ul>
|
||||
<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_pro_0003__p1129116891613">Classic load balancers can no longer be created on the management console. Use shared load balancers or dedicated load balancers instead.</p>
|
||||
</div>
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_pro_0000.html">Service Overview</a>
|
||||
|
||||
|
||||
|
||||
File diff suppressed because it is too large
Load Diff
@ -1,26 +0,0 @@
|
||||
<a name="elb_pro_0005"></a><a name="elb_pro_0005"></a>
|
||||
|
||||
<h1 class="topictitle1">Product Advantages</h1>
|
||||
<h4 class="sectiontitle">Dedicated Load Balancers</h4><ul id="elb_pro_0005__ul4438681418511"><li id="elb_pro_0005__li61386558161449">Robust performance<p id="elb_pro_0005__p41704924161458"><a name="elb_pro_0005__li61386558161449"></a><a name="li61386558161449"></a>Each dedicated load balancer has exclusive use of isolated underlying resources and can provide guaranteed performance. A single dedicated load balancer deployed in one AZ can establish up to 20 million concurrent connections, and a load balancer deployed across two AZs can establish up to 40 million concurrent connections, meeting your requirements for handling a massive number of requests.</p>
|
||||
</li><li id="elb_pro_0005__li910139118614">High availability<p id="elb_pro_0005__p1480365618614"><a name="elb_pro_0005__li910139118614"></a><a name="li910139118614"></a>Underlying resources are deployed in clusters to ensure that load balancers can route traffic uninterruptedly. If your servers in one AZ are unhealthy, dedicated load balancers automatically route traffic to healthy servers in other AZs. Dedicated load balancers provide a comprehensive health check mechanism to ensure that incoming traffic is routed to only healthy backend servers, improving the availability of your applications.</p>
|
||||
</li><li id="elb_pro_0005__li6423824716">Ultra security<p id="elb_pro_0005__p16773129816"><a name="elb_pro_0005__li6423824716"></a><a name="li6423824716"></a>Dedicated load balancers also allow you to select security policies that fit your security requirements.</p>
|
||||
</li><li id="elb_pro_0005__li248013404119">Multiple protocols<p id="elb_pro_0005__p92691543417"><a name="elb_pro_0005__li248013404119"></a><a name="li248013404119"></a>Dedicated load balancers support the following protocols, including TCP, UDP, HTTP, and HTTPS, so that they can route requests from different types of applications.</p>
|
||||
</li><li id="elb_pro_0005__li108770162710">Hybrid load balancing<p id="elb_pro_0005__p987204271"><a name="elb_pro_0005__li108770162710"></a><a name="li108770162710"></a>Dedicated load balancers can route requests to both servers on the cloud and on premises, allowing you to leverage the public cloud to handle burst traffic.</p>
|
||||
</li><li id="elb_pro_0005__li3657268018631">Ease-of-use<p id="elb_pro_0005__p6071866818631"><a name="elb_pro_0005__li3657268018631"></a><a name="li3657268018631"></a>Dedicated load balancers provide a diverse set of algorithms that allow you to configure different traffic routing policies to meet your requirements while keeping deployments simple.</p>
|
||||
</li><li id="elb_pro_0005__li678521215145">High reliability<p id="elb_pro_0005__p147852122146"><a name="elb_pro_0005__li678521215145"></a><a name="li678521215145"></a>Load balancers can be deployed across AZs and can distribute traffic more evenly.</p>
|
||||
</li></ul>
|
||||
|
||||
<h4 class="sectiontitle"><span id="elb_pro_0005__ph1618614416413">Shared</span> Load Balancers</h4><ul id="elb_pro_0005__ul18732151715418"><li id="elb_pro_0005__li97321617443">Robust performance<p id="elb_pro_0005__p373214171844"><a name="elb_pro_0005__li97321617443"></a><a name="li97321617443"></a>A <span id="elb_pro_0005__ph996061320370">shared</span> load balancer can establish up to 100 million concurrent connections and up to 1 million new connections per second, and can handle up to 1 million requests per second, meeting your requirements for handling huge numbers of concurrent requests.</p>
|
||||
</li><li id="elb_pro_0005__li117335171345">High availability<p id="elb_pro_0005__p207333172415"><a name="elb_pro_0005__li117335171345"></a><a name="li117335171345"></a>Underlying resources are deployed in clusters to ensure that load balancers can route traffic uninterruptedly. If your servers in one AZ are unhealthy, <span id="elb_pro_0005__ph72650384388">shared</span> load balancers automatically route traffic to healthy servers in other AZs. <span id="elb_pro_0005__ph43967566217">Shared</span> load balancers provide a comprehensive health check mechanism to ensure that incoming traffic is routed to only healthy backend servers, improving the availability of your applications.</p>
|
||||
</li><li id="elb_pro_0005__li27331817842">Multiple protocols<p id="elb_pro_0005__p187331017446"><a name="elb_pro_0005__li27331817842"></a><a name="li27331817842"></a><span id="elb_pro_0005__ph5591180735">Shared</span> load balancers support the following protocols, including TCP, UDP, HTTP, and HTTPS.</p>
|
||||
</li><li id="elb_pro_0005__li57333171845">Ease-of-use<p id="elb_pro_0005__p47332171346"><a name="elb_pro_0005__li57333171845"></a><a name="li57333171845"></a><span id="elb_pro_0005__ph20940541835">Shared</span> load balancers provide a diverse set of algorithms that allow you to configure different traffic routing policies to meet your requirements while keeping deployments simple.</p>
|
||||
</li><li id="elb_pro_0005__li10780918131711">High reliability<p id="elb_pro_0005__p478081871715"><a name="elb_pro_0005__li10780918131711"></a><a name="li10780918131711"></a><span id="elb_pro_0005__ph353479331">Shared</span> load balancers can be deployed across AZs and can distribute traffic more evenly.</p>
|
||||
</li></ul>
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_pro_0000.html">Service Overview</a>
|
||||
|
||||
|
||||
|
||||
@ -1,25 +0,0 @@
|
||||
<a name="elb_pro_0006"></a><a name="elb_pro_0006"></a>
|
||||
|
||||
<h1 class="topictitle1">Application Scenarios</h1>
|
||||
<h4 class="sectiontitle">Heavy-Traffic Applications</h4><p id="elb_pro_0006__p1344111419235">For an application with heavy traffic, such as a large portal or mobile app store, ELB evenly distributes incoming traffic to multiple backend servers, balancing the load while ensuring steady performance.</p>
|
||||
<p id="elb_pro_0006__p27855038171257">Sticky sessions ensure that requests from one client are always forwarded to the same backend server for fast processing.</p>
|
||||
<span class="figcap"><b>Figure 1 </b>Session stickiness</span><br><span><img class="vsd" id="elb_pro_0006__image7238166114817" src="en-us_image_0202102748.png"></span>
|
||||
|
||||
<h4 class="sectiontitle">Applications with Predictable Peaks and Troughs in Traffic</h4><p id="elb_pro_0006__p5408524171345">For an application that has predictable peaks and troughs in traffic volumes, ELB works with AS to add or remove backend servers to keep up with changing demands. An example is flash sales, during which application traffic spikes in a short period. ELB can work with AS to run only the required number of backend servers to handle the load of your application.</p>
|
||||
<span class="figcap"><b>Figure 2 </b>Flexible scalability</span><br><span><img class="vsd" id="elb_pro_0006__image533212444485" src="en-us_image_0198606821.png"></span>
|
||||
|
||||
<h4 class="sectiontitle">Zero SPOFs</h4><p id="elb_pro_0006__p66668867171438">ELB routinely performs health checks on backend servers to monitor their healthy state. If any backend server is detected unhealthy, ELB will not route requests to this server until it recovers.</p>
|
||||
<p id="elb_pro_0006__p31765646171442">This makes ELB a good choice for running services that require high reliability, such as websites and toll collection systems.</p>
|
||||
<span class="figcap"><b>Figure 3 </b>Eliminating SPOFs</span><br><span><img class="vsd" id="elb_pro_0006__image762485204912" src="en-us_image_0198606826.png"></span>
|
||||
|
||||
<h4 class="sectiontitle">Cross-AZ Load Balancing</h4><p id="elb_pro_0006__p4089950317155">ELB can distribute traffic across AZs. When an AZ becomes faulty, ELB distributes traffic across backend servers in other AZs.</p>
|
||||
<p id="elb_pro_0006__p99690131295">ELB is ideal for banking, policing, and large application systems that require high availability.</p>
|
||||
<span class="figcap"><b>Figure 4 </b>Traffic distribution to servers in one or more AZs</span><br><span><img class="vsd" id="elb_pro_0006__image9155182417491" src="en-us_image_0198606850.png"></span>
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_pro_0000.html">Service Overview</a>
|
||||
|
||||
|
||||
|
||||
@ -1,18 +0,0 @@
|
||||
<a name="elb_pro_0008"></a><a name="elb_pro_0008"></a>
|
||||
|
||||
<h1 class="topictitle1">Integration with Other Services</h1>
|
||||
<ul id="elb_pro_0008__ul172914019501"><li id="elb_pro_0008__li49170773165743">Virtual Private Cloud (VPC)<p id="elb_pro_0008__p12051242152919"><a name="elb_pro_0008__li49170773165743"></a><a name="li49170773165743"></a>Provides IP addresses and bandwidth for load balancers.</p>
|
||||
</li><li id="elb_pro_0008__li877828094211">Auto Scaling (AS)<p id="elb_pro_0008__p14926099"><a name="elb_pro_0008__li877828094211"></a><a name="li877828094211"></a>Works with ELB to automatically scale the number of backend servers for faster traffic distribution.</p>
|
||||
</li><li id="elb_pro_0008__li28091464165756">Identity and Access Management (IAM)<p id="elb_pro_0008__p2332656216588"><a name="elb_pro_0008__li28091464165756"></a><a name="li28091464165756"></a>Provides authentication for ELB.</p>
|
||||
</li><li id="elb_pro_0008__li15363634211">Elastic Cloud Server (ECS)<p id="elb_pro_0008__p152695491733"><a name="elb_pro_0008__li15363634211"></a><a name="li15363634211"></a>Provides cloud servers to run your applications in the cloud. Configure load balancers to route traffic to the servers or containers.</p>
|
||||
</li><li id="elb_pro_0008__li8230187323">Log Tank Service (LTS)<p id="elb_pro_0008__p8728191934"><a name="elb_pro_0008__li8230187323"></a><a name="li8230187323"></a>Stores access logs of HTTP or HTTPS requests to your load balancer for query and analysis later if you have enabled access logging.</p>
|
||||
</li><li id="elb_pro_0008__li3628756017026">Cloud Trace Service (CTS)<p id="elb_pro_0008__p3187313017149"><a name="elb_pro_0008__li3628756017026"></a><a name="li3628756017026"></a>Records the operations performed on ELB resources.</p>
|
||||
</li><li id="elb_pro_0008__li41153227165811">Cloud Eye<p id="elb_pro_0008__p4197074717056"><a name="elb_pro_0008__li41153227165811"></a><a name="li41153227165811"></a>Monitors the status of load balancers and listeners, without any additional plug-in.</p>
|
||||
</li></ul>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_pro_0000.html">Service Overview</a>
|
||||
|
||||
|
||||
|
||||
@ -1,15 +0,0 @@
|
||||
<a name="elb_qs_0000"></a><a name="elb_qs_0000"></a>
|
||||
|
||||
<h1 class="topictitle1">Getting Started</h1>
|
||||
|
||||
|
||||
<ul class="ullinks">
|
||||
<li class="ulchildlink"><strong><a href="elb_qs_0001.html">Overview</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="en-us_topic_0052569751.html">Using Shared Load Balancers — Entry Level</a></strong><br>
|
||||
</li>
|
||||
<li class="ulchildlink"><strong><a href="en-us_elb_02_0001.html">Using Shared Load Balancers — Advanced Level</a></strong><br>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
|
||||
@ -1,16 +0,0 @@
|
||||
<a name="elb_qs_0001"></a><a name="elb_qs_0001"></a>
|
||||
|
||||
<h1 class="topictitle1">Overview</h1>
|
||||
<p id="elb_qs_0001__p8060118">Two examples are given to show how you can quickly create <span id="elb_qs_0001__ph1645535710329">a shared</span> load balancer to distribute incoming traffic across backend servers.</p>
|
||||
<ul id="elb_qs_0001__ul1475054835218"><li id="elb_qs_0001__li9750748135219"><strong id="elb_qs_0001__b6873144712196">Entry level</strong>: A large number of requests need to be routed to backend <span id="elb_qs_0001__text37481810578">server</span>s. Health checks are required to monitor the health of backend <span id="elb_qs_0001__text1121191217221">server</span>s to ensure that incoming traffic is routed only to healthy backend <span id="elb_qs_0001__text16161113510316">server</span>s to eliminate SPOFs and improve service availability.<span class="figcap"><b>Figure 1 </b>Entry level</span><br><span><img class="vsd" id="elb_qs_0001__image171053318320" src="en-us_image_0198607819.png"></span>
|
||||
<p id="elb_qs_0001__p275291135315">As the incoming traffic increases, you can add more <span id="elb_qs_0001__text7468955914">server</span>s to balance the load across backend servers.</p>
|
||||
</li><li id="elb_qs_0001__li89701451819"><strong id="elb_qs_0001__b760175818196">Advanced level</strong>: Two or more applications use the domain name to provide services, and requests are routed to applications based on their URLs. Forwarding policies are required to forward requests from different URLs to the corresponding backend server groups.<span class="figcap"><b>Figure 2 </b>Advanced level</span><br><span><img class="vsd" id="elb_qs_0001__image1211651338" src="en-us_image_0198607873.png"></span>
|
||||
<p id="elb_qs_0001__p144871825123811">As the incoming traffic increases, you can add more backend servers to the two backend <span id="elb_qs_0001__text124874253385">server</span> groups. You can also configure health checks to monitor the health of backend <span id="elb_qs_0001__text1953021011224">server</span>s to ensure that incoming traffic is routed only to healthy backend <span id="elb_qs_0001__text17647819133720">server</span>s.</p>
|
||||
</li></ul>
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_qs_0000.html">Getting Started</a>
|
||||
|
||||
|
||||
|
||||
@ -1,29 +0,0 @@
|
||||
<a name="elb_ug_bq_0000"></a><a name="elb_ug_bq_0000"></a>
|
||||
|
||||
<h1 class="topictitle1">Tag</h1>
|
||||
<h4 class="sectiontitle">Scenarios</h4><p id="elb_ug_bq_0000__p1362702573816">If you have a large number of cloud resources, you can assign different tags to the resources to quickly identify them and use these tags to easily manage your resources.</p>
|
||||
|
||||
<h4 class="sectiontitle">Adding a Tag to a Load Balancer</h4><p id="elb_ug_bq_0000__p16505195164615">You can add a tag to a load balancer in either of the following scenarios:</p>
|
||||
<ul id="elb_ug_bq_0000__ul28401728175019"><li id="elb_ug_bq_0000__li9839628155019">Add a tag when you create a load balancer.<p id="elb_ug_bq_0000__p940413817534"><a name="elb_ug_bq_0000__li9839628155019"></a><a name="li9839628155019"></a>For detailed operations, see <a href="en-us_topic_0015479967.html#en-us_topic_0015479967__section19343262431">Creating a Shared Load Balancer</a>.</p>
|
||||
</li><li id="elb_ug_bq_0000__li583918282505">Add a tag to an existing load balancer.<ol id="elb_ug_bq_0000__ol11229133665417"><li id="elb_ug_bq_0000__li677391520332">Log in to the management console.</li><li id="elb_ug_bq_0000__li675519100420">In the upper left corner of the page, click <span><img id="elb_ug_bq_0000__en-us_topic_0240829509_image177714713415" src="en-us_image_0241356603.png"></span> and select the desired region and project.</li><li id="elb_ug_bq_0000__li83736197297">Hover on <span><img id="elb_ug_bq_0000__en-us_topic_0052569751_en-us_topic_0052569751_image616618613" src="en-us_image_0000001120894978.png"></span> in the upper left corner to display <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b9121102522212">Service List</strong> and choose <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b61222025142217">Network</strong> > <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b4124425142210">Elastic Load Balancing</strong>.</li><li id="elb_ug_bq_0000__li1222911365545">Locate the load balancer and click its name.</li><li id="elb_ug_bq_0000__li7981103114568">Under <strong id="elb_ug_bq_0000__b84235270612121">Tags</strong>, click <strong id="elb_ug_bq_0000__b8423527061224">Add Tag</strong>.</li><li id="elb_ug_bq_0000__li206491583010">In the <strong id="elb_ug_bq_0000__b2115587242165643">Add Tag</strong> dialog box, enter a tag key and value and click <strong id="elb_ug_bq_0000__b611835798165643">OK</strong>.<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><ul id="elb_ug_bq_0000__ul1459215541328"><li id="elb_ug_bq_0000__li3592854126">A maximum of 20 tags can be added to a load balancer.</li><li id="elb_ug_bq_0000__li1659275414213">Each tag is a key-value pair, and the tag key is unique.</li></ul>
|
||||
</div>
|
||||
</li></ol>
|
||||
</li></ul>
|
||||
|
||||
<h4 class="sectiontitle">Adding a Tag to a Listener</h4><p id="elb_ug_bq_0000__p078516156810">You can add tags when you add listeners.</p>
|
||||
<p id="elb_ug_bq_0000__p1868913231548">To add a tag to an existing listener, perform the following steps:</p>
|
||||
<ol id="elb_ug_bq_0000__ol18792714101"><li id="elb_ug_bq_0000__li115212495820">Log in to the management console.</li><li id="elb_ug_bq_0000__li15529419589">In the upper left corner of the page, click <span><img id="elb_ug_bq_0000__en-us_topic_0240829509_image177714713415_1" src="en-us_image_0241356603.png"></span> and select the desired region and project.</li><li id="elb_ug_bq_0000__li17301740102218">Hover on <span><img id="elb_ug_bq_0000__en-us_topic_0052569751_en-us_topic_0052569751_image616618613_1" src="en-us_image_0000001120894978.png"></span> in the upper left corner to display <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b9121102522212_1">Service List</strong> and choose <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b61222025142217_1">Network</strong> > <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b4124425142210_1">Elastic Load Balancing</strong>.</li><li id="elb_ug_bq_0000__li15101427161014">Locate the load balancer and click its name.</li><li id="elb_ug_bq_0000__li8487359151011">Click <strong id="elb_ug_bq_0000__b842352706163816">Listeners</strong>, locate the listener, and click its name.</li><li id="elb_ug_bq_0000__li8155171491312">Under <strong id="elb_ug_bq_0000__b842352706165356">Tags</strong>, click <strong id="elb_ug_bq_0000__b842352706165539">Add Tag</strong>.</li><li id="elb_ug_bq_0000__li16111627151011">In the <strong id="elb_ug_bq_0000__b487248886">Add Tag</strong> dialog box, enter a tag key and value and click <strong id="elb_ug_bq_0000__b352336256">OK</strong>.<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><ul id="elb_ug_bq_0000__ul332819417158"><li id="elb_ug_bq_0000__li932820411151">A maximum of 20 tags can be added to a listener.</li><li id="elb_ug_bq_0000__li132915415152">Each tag is a key-value pair, and the tag key is unique.</li></ul>
|
||||
</div>
|
||||
</li></ol>
|
||||
<p id="elb_ug_bq_0000__p38741451272"></p>
|
||||
|
||||
<h4 class="sectiontitle">Modifying a Tag</h4><ol id="elb_ug_bq_0000__ol1698016422035"><li id="elb_ug_bq_0000__li1780018151587">Log in to the management console.</li><li id="elb_ug_bq_0000__li480015155581">In the upper left corner of the page, click <span><img id="elb_ug_bq_0000__en-us_topic_0240829509_image177714713415_2" src="en-us_image_0241356603.png"></span> and select the desired region and project.</li><li id="elb_ug_bq_0000__li3915642514">Hover on <span><img id="elb_ug_bq_0000__en-us_topic_0052569751_en-us_topic_0052569751_image616618613_2" src="en-us_image_0000001120894978.png"></span> in the upper left corner to display <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b9121102522212_2">Service List</strong> and choose <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b61222025142217_2">Network</strong> > <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b4124425142210_2">Elastic Load Balancing</strong>.</li><li id="elb_ug_bq_0000__li69321144732">Locate the load balancer and click its name.</li><li id="elb_ug_bq_0000__li39326442032">Click <strong id="elb_ug_bq_0000__b14429401261262">Tags</strong>, select the tag to be edited, and click <strong id="elb_ug_bq_0000__b8423527061276">Edit</strong> in the <strong id="elb_ug_bq_0000__b8423527061273">Operation</strong> column. In the <strong id="elb_ug_bq_0000__b8730353761262">Edit Tag</strong> dialog box, change the tag value.<img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><p id="elb_ug_bq_0000__p34251844869">The tag key cannot be changed.</p>
|
||||
</div>
|
||||
</li><li id="elb_ug_bq_0000__li81253361963">Click <strong id="elb_ug_bq_0000__b842352706105230">OK</strong>.</li></ol>
|
||||
<p id="elb_ug_bq_0000__p167794245223">The operations for modifying a listener tag are not detailed here. Refer to the operations of modifying a load balancer tag.</p>
|
||||
|
||||
<h4 class="sectiontitle">Deleting a Tag</h4><ol id="elb_ug_bq_0000__ol14211132811713"><li id="elb_ug_bq_0000__li5274142820589">Log in to the management console.</li><li id="elb_ug_bq_0000__li72741528155818">In the upper left corner of the page, click <span><img id="elb_ug_bq_0000__en-us_topic_0240829509_image177714713415_3" src="en-us_image_0241356603.png"></span> and select the desired region and project.</li><li id="elb_ug_bq_0000__li1168141913315">Hover on <span><img id="elb_ug_bq_0000__en-us_topic_0052569751_en-us_topic_0052569751_image616618613_3" src="en-us_image_0000001120894978.png"></span> in the upper left corner to display <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b9121102522212_3">Service List</strong> and choose <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b61222025142217_3">Network</strong> > <strong id="elb_ug_bq_0000__en-us_topic_0052569751_b4124425142210_3">Elastic Load Balancing</strong>.</li><li id="elb_ug_bq_0000__li1521392816713">Locate the load balancer and click its name.</li><li id="elb_ug_bq_0000__li182134280714">Click <strong id="elb_ug_bq_0000__b164336334112833">Tags</strong>, select the tag to be deleted, and click <strong id="elb_ug_bq_0000__b99785180512833">Delete</strong> in the <strong id="elb_ug_bq_0000__b30597287512833">Operation</strong> column.</li><li id="elb_ug_bq_0000__li1495110710912">In the <strong id="elb_ug_bq_0000__b146925785212912">Delete Tag</strong> dialog box, click <strong id="elb_ug_bq_0000__b84235270612924">Yes</strong>.</li></ol>
|
||||
<p id="elb_ug_bq_0000__p836323472418">The operations for deleting a listener tag are not detailed here. Refer to the operations of deleting a load balancer tag.</p>
|
||||
|
||||
|
||||
|
||||
@ -1,23 +0,0 @@
|
||||
<a name="elb_ug_fz_0003_01"></a><a name="elb_ug_fz_0003_01"></a>
|
||||
|
||||
<h1 class="topictitle1">Network Traffic Paths</h1>
|
||||
<p id="elb_ug_fz_0003_01__elb_ug_fz_0003_p6741227008">Load balancers communicate with backend <span id="elb_ug_fz_0003_01__elb_ug_fz_0003_text12861016154612">server</span>s over a private network.</p>
|
||||
<ul id="elb_ug_fz_0003_01__elb_ug_fz_0003_ul1783718431264"><li id="elb_ug_fz_0003_01__elb_ug_fz_0003_li20837643172615">If backend <span id="elb_ug_fz_0003_01__elb_ug_fz_0003_text962105024612">server</span>s process only requests routed from load balancers, there is no need to assign EIPs or create NAT gateways.</li><li id="elb_ug_fz_0003_01__elb_ug_fz_0003_li8561715368">If backend <span id="elb_ug_fz_0003_01__elb_ug_fz_0003_text127813559469">server</span>s need to provide Internet-accessible services or access the Internet, you must assign EIPs or create NAT gateways.</li></ul>
|
||||
<h4 class="sectiontitle">Inbound Network Traffic Paths</h4>The listeners' configurations determine how load balancers distribute incoming traffic.<span class="figcap"><b>Figure 1 </b>Inbound network traffic</span><br><span><img class="vsd" id="elb_ug_fz_0003_01__elb_ug_fz_0003_image5021893716" src="en-us_image_0000001181376003.png"></span>
|
||||
|
||||
When a listener uses TCP or UDP to receive incoming traffic:<ul id="elb_ug_fz_0003_01__elb_ug_fz_0003_ul863417283383"><li id="elb_ug_fz_0003_01__elb_ug_fz_0003_li12421739938">Incoming traffic is routed only through the LVS cluster.</li><li id="elb_ug_fz_0003_01__elb_ug_fz_0003_li3634172853812">The LVS cluster directly routes incoming traffic to backend <span id="elb_ug_fz_0003_01__text1363314253911">server</span>s using the load balancing algorithm you select when you add the listener.</li></ul>
|
||||
|
||||
When a listener uses HTTP or HTTPS to receive incoming traffic:<ul id="elb_ug_fz_0003_01__elb_ug_fz_0003_ul208003244417"><li id="elb_ug_fz_0003_01__elb_ug_fz_0003_li380012244414">Incoming traffic is routed first to the LVS cluster, then to the Nginx cluster, and finally across backend <span id="elb_ug_fz_0003_01__elb_ug_fz_0003_text19960153384810">server</span>s.</li><li id="elb_ug_fz_0003_01__elb_ug_fz_0003_li97801814194412">For HTTPS traffic, the Nginx cluster validates certificates and decrypts data packets before distributing the traffic across backend servers using HTTP.</li></ul>
|
||||
|
||||
|
||||
<h4 class="sectiontitle">Outbound Network Traffic Paths</h4>The outbound traffic is routed back the same way the traffic came in.<span class="figcap"><b>Figure 2 </b>Outbound network traffic</span><br><span><img class="vsd" id="elb_ug_fz_0003_01__elb_ug_fz_0003_image1079718394379" src="en-us_image_0000001135576398.png"></span>
|
||||
<ul id="elb_ug_fz_0003_01__elb_ug_fz_0003_ul163609417566"><li id="elb_ug_fz_0003_01__li791381117196">Because the load balancer receives and responds to requests over the Internet, traffic transmission depends on the bandwidth, which is not limited by ELB. The load balancer communicates with backend servers over a private network.</li><li id="elb_ug_fz_0003_01__li8115174117209">If you have a NAT gateway, it receives and responds to incoming traffic. The NAT gateway has an EIP bound, through which backend servers can access the Internet and provide services accessible from the Internet. Although there is a restriction on the connections that can be processed by a NAT gateway, traffic transmission depends on the bandwidth</li><li id="elb_ug_fz_0003_01__elb_ug_fz_0003_li9346527125312">If each backend server has an EIP bound, they receive and respond to incoming traffic directly. Traffic transmission depends on the bandwidth.</li></ul>
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="elb_pro_0000.html">Service Overview</a>
|
||||
|
||||
|
||||
|
||||
@ -1,25 +0,0 @@
|
||||
<a name="elb_ug_fz_0004"></a><a name="elb_ug_fz_0004"></a>
|
||||
|
||||
<h1 class="topictitle1">Preparations for Creating a Load Balancer</h1>
|
||||
<p id="elb_ug_fz_0004__p724713239412">Before creating a load balancer, you must plan its region, network, protocol, and backend <span id="elb_ug_fz_0004__text799514911493">server</span>s.</p>
|
||||
<h4 class="sectiontitle">Region</h4>When you select a region, pay attention to the following:<ul id="elb_ug_fz_0004__ul122945544419"><li id="elb_ug_fz_0004__li1429455134417">The region must be close to your users' location to reduce network latency and improve the download speed.</li><li id="elb_ug_fz_0004__li159422344914">The region must be the same as that of backend <span id="elb_ug_fz_0004__text2082704264910">server</span>s. Currently, ELB cannot be deployed across regions.</li></ul>
|
||||
|
||||
|
||||
<h4 class="sectiontitle">Specifications</h4>Dedicated load balancers provide a broad range of specifications to meet different requirements. Specifications for network load balancing are suitable for TCP or UDP requests, while specifications for application load balancing are broadly used to handle HTTP or HTTPS requests. Select appropriate specifications based on your traffic volume and service requirements. The following are some principles for you to select the specifications:<ul id="elb_ug_fz_0004__en-us_topic_0172664952_ul9876138193014"><li id="elb_ug_fz_0004__en-us_topic_0172664952_li5877138203011">For TCP or UDP load balancing, pay attention to the number of concurrent persistent connections, and consider Maximum Connections as a key metric. Estimate the maximum number of concurrent connections that a load balancer can handle in the actual service scenario and select the corresponding specification.</li><li id="elb_ug_fz_0004__en-us_topic_0172664952_li88815913156">For HTTP or HTTPS load balancers, focus more on queries per second (QPS), which determines the service throughput of an application system. Estimate the QPS that a load balancer can handle in the actual service scenario and select the corresponding specification.</li><li id="elb_ug_fz_0004__en-us_topic_0172664952_li118771389302">Use the monitoring data from Cloud Eye to analyze the peak traffic, trend and regularity of the traffic to select the specifications more accurately.</li></ul>
|
||||
|
||||
|
||||
<h4 class="sectiontitle">Protocol</h4><p id="elb_ug_fz_0004__p136212239911">ELB provides load balancing at both Layer 4 and Layer 7.</p>
|
||||
<ul id="elb_ug_fz_0004__ul92693811416"><li id="elb_ug_fz_0004__li1926123841410">If you choose TCP or UDP, the load balancer routes requests directly to backend <span id="elb_ug_fz_0004__text14441101117504">server</span>s. In this process, the destination IP address in the packets is changed to the IP address of the backend server, and the source IP address to the private IP address of the load balancer. A connection is established after a three-way handshake between the client and the backend server, and the load balancer only forwards the data.<span class="figcap"><b>Figure 1 </b>Layer-4 load balancing</span><br><span><img id="elb_ug_fz_0004__image94091572359" src="en-us_image_0238395032.png"></span>
|
||||
</li><li id="elb_ug_fz_0004__li11289161375414">Load balancing at Layer 7 is also called "content exchange". After the load balancer receives a request, it works as a proxy of backend <span id="elb_ug_fz_0004__text15404133255017">server</span>s to establish a connection (three-way handshake) with the client and then determines to which backend <span id="elb_ug_fz_0004__text1860995764312">server</span> the request is to be routed based on the fields in the HTTP/HTTPS request header and the load balancing algorithm you selected when you add the listener.<span class="figcap"><b>Figure 2 </b>Layer-7 load balancing</span><br><span><img id="elb_ug_fz_0004__image491215548365" src="en-us_image_0238395033.png"></span>
|
||||
</li></ul>
|
||||
|
||||
<h4 class="sectiontitle">Backend Servers</h4><p id="elb_ug_fz_0004__p19244151032311">Before you use ELB, you need to create cloud servers, deploy required applications on them, and add the cloud servers to one or more backend <span id="elb_ug_fz_0004__text88361130165115">server</span> groups. When you create ECSs or BMSs, note the following:</p>
|
||||
<ul id="elb_ug_fz_0004__ul239818617405"><li id="elb_ug_fz_0004__li73980634016">Cloud servers must be in the same region as the load balancer.</li><li id="elb_ug_fz_0004__li183983674015">Cloud servers that run the same OS are recommended so that you can manage them more easily.</li></ul>
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="en-us_elb_03_0001.html">Load Balancer</a>
|
||||
|
||||
|
||||
|
||||
@ -1,18 +0,0 @@
|
||||
<a name="elb_ug_fz_0006"></a><a name="elb_ug_fz_0006"></a>
|
||||
|
||||
<h1 class="topictitle1">Modifying Load Balancer Settings</h1>
|
||||
<h4 class="sectiontitle">Scenarios</h4><p id="elb_ug_fz_0006__p0795439102515">You can modify the bandwidth used by the EIP bound to the load balancer as required.</p>
|
||||
|
||||
<h4 class="sectiontitle">Procedure</h4><ol id="elb_ug_fz_0006__ol1889111542441"><li id="elb_ug_fz_0006__li677391520332">Log in to the management console.</li><li id="elb_ug_fz_0006__li675519100420">In the upper left corner of the page, click <span><img id="elb_ug_fz_0006__en-us_topic_0240829509_image177714713415" src="en-us_image_0241356603.png"></span> and select the desired region and project.</li><li id="elb_ug_fz_0006__li83736197297">Hover on <span><img id="elb_ug_fz_0006__en-us_topic_0052569751_en-us_topic_0052569751_image616618613" src="en-us_image_0000001120894978.png"></span> in the upper left corner to display <strong id="elb_ug_fz_0006__en-us_topic_0052569751_b9121102522212">Service List</strong> and choose <strong id="elb_ug_fz_0006__en-us_topic_0052569751_b61222025142217">Network</strong> > <strong id="elb_ug_fz_0006__en-us_topic_0052569751_b4124425142210">Elastic Load Balancing</strong>.</li><li id="elb_ug_fz_0006__li8639162635917">On the <strong id="elb_ug_fz_0006__b7215740182117">Load Balancers</strong> page:<p id="elb_ug_fz_0006__p168247101510">Dedicated load balancers: Click <strong id="elb_ug_fz_0006__b535212248226">Elastic Load Balancers</strong>, locate the load balancer whose bandwidth you want to modify and click <strong id="elb_ug_fz_0006__b6394165114224">Modify IPv4 Bandwidth</strong> or <strong id="elb_ug_fz_0006__b102751614237">More</strong> > <strong id="elb_ug_fz_0006__b523745172318">Modify IPv6 Bandwidth</strong> in the <strong id="elb_ug_fz_0006__b0527171258">Operation</strong> column (if the load balancer has an IPv6 address that has been added to a shared bandwidth).</p>
|
||||
<p id="elb_ug_fz_0006__p551912271218">Shared load balancers: Click <strong id="elb_ug_fz_0006__b1717051182319">Elastic Load Balancers</strong>, locate the load balancer whose bandwidth you want to modify and click <strong id="elb_ug_fz_0006__b1571865115239">Modify Bandwidth</strong> or <strong id="elb_ug_fz_0006__b107191051122314">Modify IPv4 Bandwidth</strong> in the <strong id="elb_ug_fz_0006__b15525141218259">Operation</strong> column (in regions where either dedicated load balancers or both shared and dedicated load balancers are available).</p>
|
||||
<p id="elb_ug_fz_0006__p781616251400">Classic load balancers: Locate the load balancer whose bandwidth you want to modify and click <strong id="elb_ug_fz_0006__b1263212464245">Modify Bandwidth</strong> in the <strong id="elb_ug_fz_0006__b4634104610249">Operation</strong> column.</p>
|
||||
</li><li id="elb_ug_fz_0006__li112257373413">In the <strong id="elb_ug_fz_0006__b11756555165919">New Configuration</strong> area, change the bandwidth and click <strong id="elb_ug_fz_0006__b482021520111">Next</strong>.<p id="elb_ug_fz_0006__p2383161311456">Select the bandwidth defined by the system or enter a value from 1 Mbit/s to 2,000 Mbit/s.</p>
|
||||
</li><li id="elb_ug_fz_0006__li153832355312">Confirm the modified bandwidth and click Submit.</li></ol>
|
||||
|
||||
|
||||
|
||||
|
||||
<strong>Parent topic:</strong> <a href="en-us_elb_03_0001.html">Load Balancer</a>
|
||||
|
||||
|
||||
|
||||
Some files were not shown because too many files have changed in this diff Show More
Loading…
x
Reference in New Issue
Block a user