[ROCKETMQ-309] Add new consumer implement

[lyy4j]

When application use consume client in Broadcast model which runs in the docker,we can pull message only from fist offset, because docker allocate the apps at random and cause the store file do not reuse. However, we only want to pull message from last offset sometimes even though the apps runs in the docker, and we can use MQBroadcastFromLastConsumer in this case.

[zhouxinyu]

Did you mean CONSUME_FROM_LAST_OFFSET don't take effect for the broadcast model?

BTW, could you please report a JIRA issue before submitting a pull request?

[lyy4j]

@zhouxinyu ,sorry I have modify my commented again .

[lyy4j]

I have report JIRA ISSUE(309), would you have check ? @zhouxinyu

[zhouxinyu]

Thanks, let's discuss in ROCKETMQ-309 first~

[lyy4j]

even if the apps do not run in the docker, it also has the problem.
for exmaple ,
the client has consume offset 3, and flush the store file , and the consumer shutdown .
in the mean while ,the broker offset has increan from 3 to 6;
when the client reboot , it only can consum offset from 3 ,but we want consum offset 6 only.

[lyy4j]

what about the result of this pull request？ @zhouxinyu

[zhouxinyu]

Yes, It's exactly expected, CONSUME_FROM_LAST_OFFSET only take effect at the first subscription action of the consumer, you can reset the offset of stale consumers by mqadmin tool.

Consume from the last offset for each restart isn't common.

[lindzh]

@lyy4j When using Broadcast Model , offset is stored in local. If you are using docker,please map volume offset store directory to host.

[francisoliverlee]

@zhouxinyu
when CONSUME_FROM_LAST_OFFSET is set ,
for old consumers, they would use last offset when every restart, right?
for new consumers, they would use offset=0. it means new consumers will consume all messages the broker have got since it start, am i right?

[vsair]

---for old consumers, they would use last offset when every restart, right? it's right. ---for new consumers, they would use offset=0. it means new consumers will consume all messages the broker have got since it start, am i right? Should from max offset, not 0.

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On Fri, Jun 8, 2018 at 12:07 AM, francis lee ***@***.***> wrote: @zhouxinyu <https://github.com/zhouxinyu> when CONSUME_FROM_LAST_OFFSET is set , for old consumers, they would use last offset when every restart, right? for new consumers, they would use offset=0. it means new consumers will consume all messages the broker have got since it start, am i right? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#190 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACeujcWPW59NBdBiQb8uZDaXbUPSalUKks5t6U-2gaJpZM4QPkAm> .