[GitHub] [rocketmq] raftonsea commented on issue #1918: About consumers stopping pulling messages

[GitBox <gi...@apache.org>]

raftonsea commented on issue #1918: About consumers stopping pulling messages
URL: https://github.com/apache/rocketmq/issues/1918#issuecomment-612447520
 
 
   I also meet the same problem.  My consumer seems like not stopped  , but it refuse consme data . In my scenario ,  I have a topic ( vacc_top )  with   48 messageQueues  among 3 brokers , I found that it stopped consume in mq4  which  reside in  broker-a . But the consumer has not stopped , I send a message to the topic by mq-console , it works normal . It just  delays some messages  .  When I restart my application or start a new consumer   the delay disappear  and everything is fine .   
   
   In my opinion , it seems like the MQ-PullRequest exit by some reason so the mq cannot be consumed .  I debugged the consumer code , I found the code below in   DefaultMQPushConsumerImpl 
   
   ` if (processQueue.isDropped()) {
               log.info("the pull request[{}] is dropped.", pullRequest.toString());
               return;
           }`
     
   `  if (pullResult.getNextBeginOffset() < prevRequestOffset
                                   || firstMsgOffset < prevRequestOffset) {
                                   log.warn(
                                       "[BUG] pull message result maybe data wrong, nextBeginOffset: {} firstMsgOffset: {} prevRequestOffset: {}",
                                       pullResult.getNextBeginOffset(),
                                       firstMsgOffset,
                                       prevRequestOffset);
                               }`
   
   
   
   It seems that : 
   1 , the processQueue is stopped (  perhaps because of expired , when doRebalance  rocketmq will evaluate the last pull timestamp of the processqueue  to decide  weather to expir the processqueue )  so the mq stop consume . 
   2 , the pullRequest get wrong offset from broker ( the next pull offset from the pullResult  is   less than the  previous pull offset)  , so the  pullRequest exit .  
   
   As everything become ok after I restart my consumer , so I prefer the first reason . 
   I will inspect my log carefully and hope  my case will be helpful . 
   Thanks . 
   

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services