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

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

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.

Obtaining SDK Logs

The communication protocol between the RocketMQ client and server is complex. For example, the allocation of consumption queues and addressing of topics are determined by the client SDK. Important information about these processes is stored in SDK logs. When a production or consumption problem occurs, SDK logs are one of the most important methods for troubleshooting. Therefore, you must save these logs. Generally, SDK logs and service logs are not printed in the same file. Table 1 lists the default paths of common SDK logs.