Create subscriptionGroup through the command line and set the maximum number of retries for retryMaxTimes, which does not take effect：RocketMQ4.9.4

[onejimmyboy]

create new group
./mqadmin updateSubGroup -b localhost:10911 -n localhost:9876 -r 1 -w 1 -s true -i 0 -c DefaultCluster -g test100
//consumer failed
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("group003",getAcl(),new AllocateMessageQueueAveragely());
consumer.setNamesrvAddr("localhost:9876");
consumer.subscribe("topic003","*");
consumer.registerMessageListener(new MessageListenerConcurrently() {
@OverRide
public ConsumeConcurrentlyStatus consumeMessage(List list,
ConsumeConcurrentlyContext consumeConcurrentlyContext) {
System.out.println("接收到的消息内容为：+"+ list);
return ConsumeConcurrentlyStatus.RECONSUME_LATER;
}
});
consumer.start();

What is expected to see?
Retry consumption 2 times

What did you see instead?
Retry consumption 16 times
Please tell us about your environment:
Rocketmq 4.9.4

After looking at the source code, it should be judged wrong here，
Although the maximum number of retries in the group is obtained here, it will be obtained from the header if the version is greater than 3.4.9. I don't know why this is done

[ShadowySpirits]

maxReconsumeTimesœ specified by the client takes precedence.

rocketmq/client/src/main/java/org/apache/rocketmq/client/consumer/DefaultMQPushConsumer.java

Lines 248 to 255 in 6fd1bb9

	/**
	* Max re-consume times.
	* In concurrently mode, -1 means 16;
	* In orderly mode, -1 means Integer.MAX_VALUE.
	*
	* If messages are re-consumed more than {@link #maxReconsumeTimes} before success.
	*/
	private int maxReconsumeTimes = -1;

[ShadowySpirits]

The option r was added in UpdateSubGroupSubCommand since a very early version, but it is meanless now. IMO, we should remove this option.

[onejimmyboy]

命令行删除这个可配置项也是一个解除误解的方法，反过来想一下，从consumerGroup的角度设置最大重试次数也是合理的，如果设置了，那每一个客户端就不用单独再设置了，作为同一设置的入口。如果客户端想单独设置，不使用consumerGroup的最大重试次数，也是可以自己设置的。不知道这种想法合理不？

[ShadowySpirits]

According to the java doc of DefaultMQPushConsumer#maxReconsumeTimes, maxReconsumeTimes has a default value of -1, which translates to 16 in concurrent mode. This strategy is implemented on the client side.

rocketmq/client/src/main/java/org/apache/rocketmq/client/impl/consumer/DefaultMQPushConsumerImpl.java

Lines 867 to 874 in 37ff93a

	public int getMaxReconsumeTimes() {
	// default reconsume times: 16
	if (this.defaultMQPushConsumer.getMaxReconsumeTimes() == -1) {
	return 16;
	} else {
	return this.defaultMQPushConsumer.getMaxReconsumeTimes();
	}
	}

It is better to obey the subscription group config in the server when maxReconsumeTimes is not set by the user. However, given compatibility issues, we need more discussion.

[ShadowySpirits]

@aaron-ai What do you think? And is maxReconsumeTimes in the grpc client using the same way?

[drpmma]

The gRPC client uses the retryMaxTimes in SubscriptionGroupConfig.

See

rocketmq/proxy/src/main/java/org/apache/rocketmq/proxy/grpc/v2/common/GrpcClientSettingsManager.java

Lines 102 to 109 in 83c4a8f

	protected Settings mergeSubscriptionData(ProxyContext ctx, Settings settings, String consumerGroup) {
	SubscriptionGroupConfig config = this.messagingProcessor.getSubscriptionGroupConfig(ctx, consumerGroup);
	if (config == null) {
	return settings;
	}
	return mergeSubscriptionData(settings, config);
	}

rocketmq/proxy/src/main/java/org/apache/rocketmq/proxy/grpc/v2/common/GrpcClientSettingsManager.java

Lines 140 to 167 in 83c4a8f

	protected static Settings mergeSubscriptionData(Settings settings, SubscriptionGroupConfig groupConfig) {
	Settings.Builder resultSettingsBuilder = settings.toBuilder();
	ProxyConfig config = ConfigurationManager.getProxyConfig();
	resultSettingsBuilder.getSubscriptionBuilder()
	.setReceiveBatchSize(config.getGrpcClientConsumerLongPollingBatchSize())
	.setLongPollingTimeout(Durations.fromMillis(config.getGrpcClientConsumerMaxLongPollingTimeoutMillis()))
	.setFifo(groupConfig.isConsumeMessageOrderly());
	resultSettingsBuilder.getBackoffPolicyBuilder().setMaxAttempts(groupConfig.getRetryMaxTimes() + 1);
	GroupRetryPolicy groupRetryPolicy = groupConfig.getGroupRetryPolicy();
	if (groupRetryPolicy.getType().equals(GroupRetryPolicyType.EXPONENTIAL)) {
	ExponentialRetryPolicy exponentialRetryPolicy = groupRetryPolicy.getExponentialRetryPolicy();
	if (exponentialRetryPolicy == null) {
	exponentialRetryPolicy = new ExponentialRetryPolicy();
	}
	resultSettingsBuilder.getBackoffPolicyBuilder().setExponentialBackoff(convertToExponentialBackoff(exponentialRetryPolicy));
	} else {
	CustomizedRetryPolicy customizedRetryPolicy = groupRetryPolicy.getCustomizedRetryPolicy();
	if (customizedRetryPolicy == null) {
	customizedRetryPolicy = new CustomizedRetryPolicy();
	}
	resultSettingsBuilder.getBackoffPolicyBuilder().setCustomizedBackoff(convertToCustomizedRetryPolicy(customizedRetryPolicy));
	}
	return resultSettingsBuilder.build();
	}