Help Center/ Distributed Message Service for RocketMQ/ User Guide/ Accessing an Instance/ Configuring a RocketMQ Client
Updated on 2026-01-07 GMT+08:00
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Configuring a RocketMQ Client

Suggestions on configuring a RocketMQ client.

Java Client Version

5.1.4 and later are recommended.

Unique ClientId

By default, ClientId combines the process ID, local IP address, and instance name. When two consumers in a consumer group are started in a process, their ClientIds are the same. As a result, some queues are repeatedly consumed and others cannot be consumed.

Recommended Setting

ClientId is generated with clientIP of a consumer. If different consumers share a clientIP at the same IP address, ClientId will be the same. You are advised to add the following code to manually set instanceName. 
consumer.setInstanceName(String.valueOf(System.nanoTime()))

Producer Exception Detection

Available in Java client 5.1.4 and later.

Enable exception detection on a client. When accessing a broker times out, the client can quickly switch to another broker for message production.

producer.setSendLatencyFaultEnable(true)

Error Code SYSTEM_BUSY for Producer Retry

Producers are advised to configure error codes for retry. When SYSTEM_BUSY is returned due to exceptions such as busy disk writing or master/slave switchover, resending messages to other normal brokers can reduce service impact. 
producer.addRetryResponseCode(ResponseCode.SYSTEM_BUSY);

Function addRetryResponseCode is available only for client 4.9.2 and later. Note that SYSTEM_BUSY is added by default for client 5.2.1 and later.

Parent Topic: Accessing an Instance