Modifying Kafka Parameters

Scenario

Your Kafka instances, topics, and consumers come with default configuration parameter settings. You can modify common parameters on the DMS console. For details about parameters that are not listed on the console, see the Kafka official website.

Parameters of v1.1.0 instances are all static parameters. v2.3.0/2.7 instances have both dynamic and static parameters.

• Dynamic parameters: Modifying dynamic parameters will not restart the instance.
• Static parameters: After static parameters are modified, you must manually restart the instance.

Prerequisites

You can modify configuration parameters of a Kafka instance when the instance is in the Running state.

Procedure

1. Log in to the management console.
2. Click in the upper left corner to select a region.
   

   Select the region where your Kafka instance is located.

3. Click Service List and choose Application > Distributed Message Service. The Kafka instance list is displayed.
4. Click the desired Kafka instance to view the instance details.
5. On the Parameters tab page, click Edit in the row containing the parameter to modify. Table 1 describes the parameters of v1.1.0 instances. Table 2 and Table 3 describe the parameters of v2.3.0/2.7 instances.

   Table 1 Static parameters (v1.1.0 instances)

   Parameter	Description	Value Range	Default Value
   min.insync.replicas	If a producer sets the acks parameter to all (or -1), the min.insync.replicas parameter specifies the minimum number of replicas that must acknowledge a write for the write to be considered successful.	1–3	1
   message.max.bytes	Maximum length of a single message, in bytes.	0–10,485,760	10,485,760
   unclean.leader.election.enable	Indicates whether to allow replicas not in the ISR set to be elected as the leader as a last resort, even though doing so may result in data loss.	true or false	true
   connections.max.idle.ms	Idle connection timeout (in ms). Connections that are idle for the duration specified by this parameter will be closed.	5000–600,000	600,000
   log.retention.hours	Duration (in hours) for retaining a log file. This parameter takes effect only for topics that have no aging time configured. If there is aging time configured for topics, it overrides this parameter.	1–168	72
   max.connections.per.ip	The maximum number of connections allowed from each IP address. Request for new connections will be rejected once the limit is reached. The limit set using this parameter will be replaced if there are overrides configured using the max.connections.per.ip.overrides parameter.	100–20,000	1000
   group.max.session.timeout.ms	The maximum session timeout (in ms) for consumers. A longer timeout gives consumers more time to process messages between heartbeats but results in a longer time to detect failures.	6000–1,800,000	1,800,000
   default.replication.factor	The default number of replicas configured for an automatically created topic.	1–3	3
   num.partitions	The default number of partitions configured for each automatically created topic.	1–100	3
   group.min.session.timeout.ms	The minimum session timeout (in ms) for consumers. A shorter timeout enables quicker failure detection but results in more frequent consumer heartbeating, which can overwhelm broker resources.	6000–300,000	6000

   Table 2 Dynamic parameters (v2.3.0/2.7 instances)

   Parameter	Description	Value Range	Default Value
   min.insync.replicas	If a producer sets the acks parameter to all (or -1), the min.insync.replicas parameter specifies the minimum number of replicas that must acknowledge a write for the write to be considered successful.	1–3	1
   message.max.bytes	Maximum length of a single message, in bytes.	0–10,485,760	10,485,760
   unclean.leader.election.enable	Indicates whether to allow replicas not in the ISR set to be elected as the leader as a last resort, even though doing so may result in data loss.	true or false	true

   Table 3 Static parameters (v2.3.0/2.7 instances)

   Parameter	Description	Value Range	Default Value
   connections.max.idle.ms	Idle connection timeout (in ms). Connections that are idle for the duration specified by this parameter will be closed.	5000–600,000	600,000
   log.retention.hours	Duration (in hours) for retaining a log file. This parameter takes effect only for topics that have no aging time configured. If there is aging time configured for topics, it overrides this parameter.	1–168	72
   max.connections.per.ip	The maximum number of connections allowed from each IP address. Request for new connections will be rejected once the limit is reached. The limit set using this parameter will be replaced if there are overrides configured using the max.connections.per.ip.overrides parameter.	100–20,000	1000
   group.max.session.timeout.ms	The maximum session timeout (in ms) for consumers. A longer timeout gives consumers more time to process messages between heartbeats but results in a longer time to detect failures.	6000–1,800,000	1,800,000
   default.replication.factor	The default number of replicas configured for an automatically created topic.	1–3	3
   num.partitions	The default number of partitions configured for each automatically created topic.	1–100	3
   group.min.session.timeout.ms	The minimum session timeout (in ms) for consumers. A shorter timeout enables quicker failure detection but results in more frequent consumer heartbeating, which can overwhelm broker resources.	6000–300,000	6000

   

   • To modify multiple dynamic or static parameters at a time, click Modify above the parameter list.
   • If you want to restore the default values, click Restore Default in the row containing the desired parameter.

6. Click Save.
   

   Modifying dynamic parameters will not restart the instance. Static parameter modification requires manual restart of the instance.