The analysis cluster, streaming cluster, and hybrid cluster provided by MRS use fixed templates to deploy cluster processes. Therefore, you cannot customize service processes on management nodes and control nodes.

A custom cluster provides the following functions:

Separated deployment of the management and control roles: The management role and control role are deployed on different Master nodes.
Co-deployment of the management and control roles: The management and control roles are co-deployed on the Master node.
ZooKeeper is deployed on an independent node to improve reliability.
Components are deployed separately to avoid resource contention.

Roles in an MRS cluster:

Management Node (MN): is the node to install Manager (the management system of the MRS cluster). It provides a unified access entry. Manager centrally manages nodes and services deployed in the cluster.
Control Node (CN): controls and monitors how data nodes store and receive data, and send process status, and provides other public functions. Control nodes of MRS include HMaster, HiveServer, ResourceManager, NameNode, JournalNode, and SlapdServer.
Data Node (DN): A data node executes the instructions sent by the management node, reports task status, stores data, and provides other public functions. Data nodes of MRS include DataNode, RegionServer, and NodeManager.

Customizing a Cluster

Log in to the MRS console.
Click Create Cluster. The page for creating a cluster is displayed.
Click the Custom Config tab.
Configure basic cluster information. For details about the parameters, see Software Configurations.
- Region: Retain the default value.
- Cluster Name: You can use the default name. However, you are advised to include a project name abbreviation or date for consolidated memory and easy distinguishing, for example, mrs_20180321.
- Cluster Version: Currently, only MRS 3.x are supported.
Click Next. Configure hardware information.
- AZ: Retain the default value.
- VPC: Retain the default value. If there is no available VPC, click View VPC to access the VPC console and create a new VPC.
- Subnet: Retain the default value.
- Security Group: Select Auto create.
- EIP: Select Bind later.
- Enterprise Project: Retain the default value.
- Common Node: For details, see Custom Cluster Template Description.
- Instance Specifications: Click to configure the instance specifications, system disk and data disk storage types, and storage space.
- Instance Count: Adjust the number of cluster instances based on the service volume. For details, see Table 2.
- Topology Adjustment: If the deployment mode in the Common Node does not meet the requirements, you need to manually install some instances that are not deployed by default, or you need to manually install some instances, set Topology Adjustment to Enable and adjust the instance deployment mode based on service requirements. For details, see Topology Adjustment for a Custom Cluster.
Click Next and set advanced options.
For details about the parameters, see (Optional) Advanced Configuration.
Click Create Now.
If Kerberos authentication is enabled for a cluster, check whether Kerberos authentication is required. If yes, click Continue. If no, click Back to disable Kerberos authentication and then create a cluster.
Click Back to Cluster List to view the cluster status.
It takes some time to create a cluster. The initial status of the cluster is Starting. After the cluster has been created successfully, the cluster status becomes Running.

Custom Cluster Template Description

**Table 1** Common templates for custom clusters
Common Node	Description	Node Range
Compact	The management role and control role are deployed on the Master node, and data instances are deployed in the same node group. This deployment mode applies to scenarios where the number of control nodes is less than 100, reducing costs.	The number of Master nodes is greater than or equal to 3 and less than or equal to 11. The total number of node groups is less than or equal to 10, and the total number of nodes in non-Master node groups is less than or equal to 10,000.
OMS-separate	The management role and control role are deployed on different Master nodes, and data instances are deployed in the same node group. This deployment mode is applicable to a cluster with 100 to 500 nodes and delivers better performance in high-concurrency load scenarios.	The number of Master nodes is greater than or equal to 5 and less than or equal to 11. The total number of node groups is less than or equal to 10, and the total number of nodes in non-Master node groups is less than or equal to 10,000.
Full-size	The management role and control role are deployed on different Master nodes, and data instances are deployed in different node groups. This deployment mode is applicable to a cluster with more than 500 nodes. Components can be deployed separately, which can be used for a larger cluster scale.	The number of Master nodes is greater than or equal to 9 and less than or equal to 11. The total number of node groups is less than or equal to 10, and the total number of nodes in non-Master node groups is less than or equal to 10,000.

**Table 2** Node deployment scheme of a customized MRS cluster
Node Deployment Principle		Applicable Scenario	Networking Rule
Management nodes, control nodes, and data nodes are deployed separately. (This scheme requires at least eight nodes.)	MN × 2 + CN × 9 + DN × n	(Recommended) This scheme is used when the number of data nodes is 500–2000.	If the number of nodes in a cluster exceeds 200, the nodes are distributed to different subnets and the subnets are interconnected with each other in Layer 3 using core switches. Each subnet can contain a maximum of 200 nodes and the allocation of nodes to different subnets must be balanced. If the number of nodes is less than 200, the nodes in the cluster are deployed in the same subnet and the nodes are interconnected with each other in Layer 2 using aggregation switches.
	MN × 2 + CN × 5 + DN × n	(Recommended) This scheme is used when the number of data nodes is 100–500.
	MN × 2 + CN × 3 + DN × n	(Recommended) This scheme is used when the number of data nodes is 30–100.
The management nodes and control nodes are deployed together, and the data nodes are deployed separately.	(MN+CN) × 3 + DN × n	(Recommended) This scheme is used when the number of data nodes is 3–30.	Nodes in the cluster are deployed in the same subnet and are interconnected with each other at Layer 2 through aggregation switches.
The management nodes, control nodes, and data nodes are deployed together.		This scheme is applicable to a cluster having fewer than 6 nodes. This scheme requires at least three nodes. NOTE: This template is not recommended in the production environment or commercial environment. If management, control, and data nodes are co-deployed, cluster performance and reliability are greatly affected. If the number of nodes meet the requirements, deploy data nodes separately. If the number of nodes is insufficient to support separately deployed data nodes, use the dual-plane networking mode for this scenario. The traffic of the management network is isolated from that of the service network to prevent excessive data volumes on the service plane, ensuring correct delivery of management operations.	Nodes in the cluster are deployed in the same subnet and are interconnected with each other at Layer 2 through aggregation switches.

Topology Adjustment for a Custom Cluster

**Table 3** Topology adjustment
Service	Dependency	Role	Role Deployment Suggestions	Description
OMSServer	-	OMSServer	This role can be deployed it on the Master node and cannot be modified.	-
ClickHouse	Depends on ZooKeeper.	CHS (ClickHouseServer)	This role can be deployed on all nodes. Number of role instances to be deployed: an even number ranging from 2 to 256	A non-Master node group with this role assigned is considered as a Core node.
ClickHouse	Depends on ZooKeeper.	CLB (ClickHouseBalancer)	This role can be deployed on all nodes. Number of role instances to be deployed: 2 to 256	-
ZooKeeper	-	QP(quorumpeer)	This role can be deployed on the Master node only. Number of role instances to be deployed: 3 to 9, with the step size of 2	-
Hadoop	Depends on ZooKeeper.	NN(NameNode)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2	The NameNode and ZKFC processes are deployed on the same server for cluster HA.
		HFS (HttpFS)	This role can be deployed on the Master node only. Number of role instances to be deployed: 0 to 10	-
		JN(JournalNode)	This role can be deployed on the Master node only. Number of role instances to be deployed: 3 to 60, with the step size of 2	-
		DN(DataNode)	This role can be deployed on all nodes. Number of role instances to be deployed: 3 to 10,000	A non-Master node group with this role assigned is considered as a Core node.
		RM(ResourceManager)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2	-
		NM(NodeManager)	This role can be deployed on all nodes. Number of role instances to be deployed: 3 to 10,000	-
		JHS(JobHistoryServer)	This role can be deployed on the Master node only. Number of role instances to be deployed: 1 to 2	-
		TLS(TimelineServer)	This role can be deployed on the Master node only. Number of role instances to be deployed: 0 to 1	-
Presto	Depends on Hive.	PCD(Coordinator)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2	-
Presto	Depends on Hive.	PWK(Worker)	This role can be deployed on all nodes. Number of role instances to be deployed: 1 to 10,000	-
Spark2x	Depends on Hadoop. Depends on Hive. Depends on ZooKeeper.	JS2X(JDBCServer2x)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2 to 10	-
		JH2X(JobHistory2x)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2	-
		SR2X(SparkResource2x)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2 to 50	-
		IS2X(IndexServer2x)	(Optional) This role can be deployed on the Master node only. Number of role instances to be deployed: 0 to 2, with the step size of 2	-
HBase	Depends on Hadoop.	HM(HMaster)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2	-
		TS(ThriftServer)	This role can be deployed on all nodes. Number of role instances to be deployed: 0 to 10,000	-
		RT(RESTServer)	This role can be deployed on all nodes. Number of role instances to be deployed: 0 to 10,000	-
		RS(RegionServer)	This role can be deployed on all nodes. Number of role instances to be deployed: 3 to 10,000	-
		TS1(Thrift1Server)	This role can be deployed on all nodes. Number of role instances to be deployed: 0 to 10,000	If the Hue service is installed in a cluster and HBase needs to be used on the Hue web UI, install this instance for the HBase service.
Hive	Depends on Hadoop. Depends on DBService.	MS(MetaStore)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2 to 10	-
		WH (WebHCat)	This role can be deployed on the Master node only. Number of role instances to be deployed: 1 to 10	-
		HS(HiveServer)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2 to 80	-
Hue	Depends on DBService.	H(Hue)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2	-
Sqoop	Depends on Hadoop.	SC(SqoopClient)	This role can be deployed on all nodes. Number of role instances to be deployed: 1 to 10,000	-
Kafka	Depends on ZooKeeper.	B(Broker)	This role can be deployed on all nodes. Number of role instances to be deployed: 3 to 10,000	-
Flume	-	MS(MonitorServer)	This role can be deployed on the Master node only. Number of role instances to be deployed: 1 to 2	-
Flume	-	F(Flume)	This role can be deployed on all nodes. Number of role instances to be deployed: 1 to 10,000	A non-Master node group with this role assigned is considered as a Core node.
Tez	Depends on Hadoop. Depends on DBService. Depends on ZooKeeper.	TUI(TezUI)	This role can be deployed on the Master node only. Number of role instances to be deployed: 1 to 2	-
Flink	Depends on ZooKeeper. Depends on Hadoop.	FR(FlinkResource)	This role can be deployed on all nodes. Number of role instances to be deployed: 1 to 10,000	-
Flink	Depends on ZooKeeper. Depends on Hadoop.	FS(FlinkServer)	This role can be deployed on all nodes. Number of role instances to be deployed: 0 to 2	-
Oozie	Depends on Hadoop. Depends on DBService. Depends on ZooKeeper.	O(oozie)	This role can be deployed on the Master node only. Number of role instances to be deployed: 2	-
Impala	Depends on Hadoop. Depends on Hive. Depends on DBService. Depends on ZooKeeper.	StateStore	This role can be deployed on the Master node only. Number of role instances to be deployed: 1	-
		Catalog	This role can be deployed on the Master node only. Number of role instances to be deployed: 1	-
		Impalad	This role can be deployed on all nodes. Number of role instances to be deployed: 1 to 10,000	-
Kudu	-	KuduMaster	This role can be deployed on the Master node only. Number of role instances to be deployed: 3 or 5	-
Kudu	-	KuduTserver	This role can be deployed on all nodes. Number of role instances to be deployed: 3 to 10,000	-
Ranger	Depends on DBService.	RA(RangerAdmin)	This role can be deployed on the Master node only. Number of role instances to be deployed: 1 to 2	-
		USC(UserSync)	This role can be deployed on the Master node only. Number of role instances to be deployed: 1	-
		TSC (TagSync)	This role can be deployed on all nodes. Number of role instances to be deployed: 0 to 1	-

Creating a Custom Topology Cluster

Customizing a Cluster

Custom Cluster Template Description

Topology Adjustment for a Custom Cluster