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.

Note

Configuration parameters of some old instances cannot be modified. Check whether your instance parameters can be modified on the console. If they cannot be modified, contact customer service.

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 image1 in the upper left corner to select a region.

    Note

    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

    Note

    • 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.

    Note

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