[jira] [Updated] (ROCKETMQ-184) It takes too long(3-33 seconds) to switch to read from slave when master crashes

["Jaskey Lam (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ROCKETMQ-184?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jaskey Lam updated ROCKETMQ-184:
--------------------------------
    Description: 
When master crashes, no notifier callback has been triggered to pull message again.

Instead, it relies on the scan service to trigger timeout and then re pull.

But the pulling command has 30 seconds timeout, and after timeout, pulling operation will be scheduled after 3 seconds.

So it takes 3 to 33 seconds to switch to slave, which is too long and can be optimized.


The root cause is the below repull cost too long to be triggered when master crashes

{code}

            @Override
            public void onException(Throwable e) {
                if (!pullRequest.getMessageQueue().getTopic().startsWith(MixAll.RETRY_GROUP_TOPIC_PREFIX)) {
                    log.warn("execute the pull request exception", e);
                }

                DefaultMQPushConsumerImpl.this.executePullRequestLater(pullRequest, PULL_TIME_DELAY_MILLS_WHEN_EXCEPTION);
            }

{code}

  was:
When master crashes, no notifier callback has been triggered to pull message again.

Instead, it relies on the scan service to trigger timeout and then re pull.

But the pulling command has 30 seconds timeout, and after timeout, pulling operation will be scheduled after 3 seconds.

So it takes 3 to 33 seconds to switch to slave, which is too long and can be optimized.


The root cause is the below re pull is too long to be triggered when master crashes

{code}

            @Override
            public void onException(Throwable e) {
                if (!pullRequest.getMessageQueue().getTopic().startsWith(MixAll.RETRY_GROUP_TOPIC_PREFIX)) {
                    log.warn("execute the pull request exception", e);
                }

                DefaultMQPushConsumerImpl.this.executePullRequestLater(pullRequest, PULL_TIME_DELAY_MILLS_WHEN_EXCEPTION);
            }

{code}


> It takes too long(3-33 seconds) to switch to read from slave when master crashes
> --------------------------------------------------------------------------------
>
>                 Key: ROCKETMQ-184
>                 URL: https://issues.apache.org/jira/browse/ROCKETMQ-184
>             Project: Apache RocketMQ
>          Issue Type: Improvement
>          Components: rocketmq-client, rocketmq-remoting
>            Reporter: Jaskey Lam
>            Assignee: Xiaorui Wang
>
> When master crashes, no notifier callback has been triggered to pull message again.
> Instead, it relies on the scan service to trigger timeout and then re pull.
> But the pulling command has 30 seconds timeout, and after timeout, pulling operation will be scheduled after 3 seconds.
> So it takes 3 to 33 seconds to switch to slave, which is too long and can be optimized.
> The root cause is the below repull cost too long to be triggered when master crashes
> {code}
>             @Override
>             public void onException(Throwable e) {
>                 if (!pullRequest.getMessageQueue().getTopic().startsWith(MixAll.RETRY_GROUP_TOPIC_PREFIX)) {
>                     log.warn("execute the pull request exception", e);
>                 }
>                 DefaultMQPushConsumerImpl.this.executePullRequestLater(pullRequest, PULL_TIME_DELAY_MILLS_WHEN_EXCEPTION);
>             }
> {code}



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