MRS-operation-guide-lts/doc/component-operation-guide/source/using_kafka/kafka_common_parameters.rst

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Kafka Common Parameters

This section applies to MRS 3.x or later.

Navigation path for setting parameters:

For details about how to set parameters, see Modifying Cluster Service Configuration Parameters <mrs_01_2125>.

Common Parameters

Table 1 Parameter description

Parameter	Description	Default Value
log.dirs	List of Kafka data storage directories. Use commas (,) to separate multiple directories.	%{@auto.detect.datapart.bk.log.logs}
KAFKA_HEAP_OPTS	Specifies the JVM option used for Kafka to start broker. It is recommended that you set this parameter based on service requirements.	-Xmx6G -Xms6G
auto.create.topics.enable	Indicates whether a topic is automatically created. If this parameter is set to false, you need to run a command to create a topic before sending a message.	true
default.replication.factor	Default number of replicas of a topic is automatically created.	2
monitor.preInitDelay	Delay of the first health check after the server is started. If the startup takes a long time, increase the value of the parameter. Unit: millisecond	600,000

Timeout Parameters

Table 2 Broker-related timeout parameters

Parameter	Description	Default Value	Impact
controller.socket.timeout.ms	Specifies the timeout for connecting controller to broker. Unit: millisecond	30,000	Generally, retain the default value of this parameter.
group.max.session.timeout.ms	Specifies the maximum session timeout during the consumer registration. Unit: millisecond	1800000	The configured value must be less than the value of this parameter.
group.min.session.timeout.ms	Specifies the minimum session timeout during the consumer registration. Unit: millisecond	6,000	The configured value must be greater than the value of this parameter.
offsets.commit.timeout.ms	Specifies the timeout for the Offset to submit requests. Unit: millisecond	5,000	This parameter specifies the maximum delay for processing an Offset request.
replica.socket.timeout.ms	Specifies the timeout of the request for synchronizing replica data. Its value must be greater than or equal to that of the replica.fetch.wait.max.ms parameter. Unit: millisecond	30,000	Specifies the maximum timeout for establishing a channel before the synchronization thread sends a synchronization request. The value must be greater than that of the replica.fetch.wait.max.ms parameter.
request.timeout.ms	Specifies the timeout for waiting for a response after the client sends a connection request. If no response is received within the timeout, the client resends the request. A request failure is returned after the maximum retry times is reached. Unit: millisecond	30,000	This parameter is configured when the networkclient connection is transferred in the controller and replica threads on the broker node.
transaction.max.timeout.ms	Specifies the maximum timeout allowed by the transaction. If the client request time exceeds the value of this parameter, broker returns an error in InitProducerIdRequest. This prevents a long client request timeout, ensuring that consumer can receive topics. Unit: millisecond	900,000	Specifies the maximum timeout for transactions.
user.group.cache.timeout.sec	Specifies the time when the user group information is stored in the cache. Unit: second	300	Specifies the time for caching the mapping between users and user groups. If time exceeds the threshold, the system automatically runs the id -Gn command to query the user information. During this period, the mapping in the cache is used.
zookeeper.connection.timeout.ms	Specifies the timeout for connecting to ZooKeeper. Unit: millisecond	45,000	This parameter specifies the duration for connecting the ZooKeeper and zkclient for the first time. If the duration exceeds the value of this parameter, the zkclient automatically disconnects the connection.
zookeeper.session.timeout.ms	Specifies the ZooKeeper session timeout duration. During this period, ZooKeeper disconnects the connection if broker does not report its heartbeats to ZooKeeper. Unit: millisecond	45,000	ZooKeeper session timeout has the following functions: Based on value of this parameter and the number of ZooKeeper URLs in ZKURL, if the connection duration exceeds the node timeout value (sessionTimeout/Number of transferred ZooKeeper URLs), the connection fails and the system attempts to connect to the next node. After the connection is established, a session (for example, the temporary BrokerId node registered on the ZooKeeper) is cleared by the ZooKeeper a session timeout later if the broker is stopped.

Table 3 Producer-related timeout parameters

Parameter	Description	Default Value	Impact
request.timeout.ms	Specifies the timeout of a message request.	30,000	If a network fault occurs, increase the value of this parameter. If the value is too small, the Batch Expire occurs.

Table 4 Consumer-related timeout parameters

Parameter	Description	Default Value	Impact
connections.max.idle.ms	Specifies the maximum retention period for idle connections.	600,000	If the idle connection time is greater than this parameter value, this connection is disconnected. If necessary, a new connection is created.
request.timeout.ms	Specifies the timeout for consumer requests.	30,000	If the request times out, the request will fail and be sent again.