Han JU created KAFKA-3146:
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Summary: Stuck consumer with new consumer API in 0.9
Key: KAFKA-3146
URL: https://issues.apache.org/jira/browse/KAFKA-3146
Project: Kafka
Issue Type: Bug
Components: consumer
Affects Versions: 0.9.0.0
Reporter: Han JU
Assignee: Neha Narkhede
I'm prototyping with the new consumer API of kafka 0.9 and I'm particularly
interested in the `ConsumerRebalanceListener`.
My test setup is like the following:
- 5M messages pre-loaded in one node kafka 0.9
- 12 partitions, auto offset commit set to false
- in `onPartitionsRevoked`, commit offset and flush the local state
The test run is like the following:
- launch one process with 2 consumers and let it consume for a while
- launch another process with 2 consumers, this triggers a rebalancing, and
let these 2 processes run until messages are all consumed
The code is here: https://gist.github.com/darkjh/fe1e5a5387bf13b4d4dd
So at first, the 2 consumers of the first process each got 6 partitions. And
after the rebalancing, each consumer got 3 partitions. It's confirmed by
logging inside the `onPartitionAssigned` callback.
But after the rebalancing, one of the 2 consumers of the first process stop
receiving messages, even if it has partitions assigned to:
balance-1 pulled 7237 msgs ...
balance-0 pulled 7263 msgs ...
2016-01-22 15:50:37,533 [INFO] [pool-1-thread-2]
o.a.k.c.c.i.AbstractCoordinator - Attempt to heart beat failed since the group
is rebalancing, try to re-join group.
balance-1 flush @ 536637
balance-1 committed offset for List(balance-11, balance-10, balance-9,
balance-8, balance-7, balance-6)
2016-01-22 15:50:37,575 [INFO] [pool-1-thread-1]
o.a.k.c.c.i.AbstractCoordinator - Attempt to heart beat failed since the group
is rebalancing, try to re-join group.
balance-0 flush @ 543845
balance-0 committed offset for List(balance-5, balance-4, balance-3, balance-2,
balance-1, balance-0)
balance-0 got assigned List(balance-5, balance-4, balance-3)
balance-1 got assigned List(balance-11, balance-10, balance-9)
balance-1 pulled 3625 msgs ...
balance-0 pulled 3621 msgs ...
balance-0 pulled 3631 msgs ...
balance-0 pulled 3631 msgs ...
balance-1 pulled 0 msgs ...
balance-0 pulled 3643 msgs ...
balance-0 pulled 3643 msgs ...
balance-1 pulled 0 msgs ...
balance-0 pulled 3622 msgs ...
balance-0 pulled 3632 msgs ...
balance-1 pulled 0 msgs ...
balance-0 pulled 3637 msgs ...
balance-0 pulled 3641 msgs ...
balance-0 pulled 3640 msgs ...
balance-1 pulled 0 msgs ...
balance-0 pulled 3632 msgs ...
balance-0 pulled 3630 msgs ...
balance-1 pulled 0 msgs ...
......
`balance-0` and `balance-1` are the names of the consumer thread. So after the
rebalancing, thread `balance-1` continues to poll but no message arrive, given
that it has got 3 partitions assigned to after the rebalancing.
Finally other 3 consumers pulls all their partitions' message, the situation is
like
GROUP, TOPIC, PARTITION, CURRENT OFFSET, LOG END OFFSET, LAG, OWNER
balance-test, balance, 9, 417467, 417467, 0, consumer-2_/127.0.0.1
balance-test, balance, 10, 417467, 417467, 0, consumer-2_/127.0.0.1
balance-test, balance, 11, 417467, 417467, 0, consumer-2_/127.0.0.1
balance-test, balance, 6, 180269, 417467, 237198, consumer-2_/127.0.0.1
balance-test, balance, 7, 180036, 417468, 237432, consumer-2_/127.0.0.1
balance-test, balance, 8, 180197, 417467, 237270, consumer-2_/127.0.0.1
balance-test, balance, 3, 417467, 417467, 0, consumer-1_/127.0.0.1
balance-test, balance, 4, 417468, 417468, 0, consumer-1_/127.0.0.1
balance-test, balance, 5, 417468, 417468, 0, consumer-1_/127.0.0.1
balance-test, balance, 0, 417467, 417467, 0, consumer-1_/127.0.0.1
balance-test, balance, 1, 417467, 417467, 0, consumer-1_/127.0.0.1
balance-test, balance, 2, 417467, 417467, 0, consumer-1_/127.0.0.1
So you can see, partition [6, 7, 8] still has messages, but the consumer can't
pull them after the rebalancing.
I've tried 0.9.0.0 release, trunk and 0.9.0 branch, for both server/broker and
client.
One workaround (by Bruno Rassaerts), is to do a manual seek to the current
position in the `onPartitionsAssigned` call back.
The corresponding mailing list discussion is here:
http://mail-archives.apache.org/mod_mbox/kafka-users/201601.mbox/%3CCA%2BndhHok%3DemRceLuhwGHKwMCVQSmgTUeaxs-ycK-U2nLcc8Uhg%40mail.gmail.com%3E
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