Thanks for the explanation. It there a way that I can wipe out the offset
stored in kafka so that the checker can continue to work again?
On Fri, Feb 13, 2015 at 1:31 PM, Jiangjie Qin <j...@linkedin.com.invalid>
wrote:
> I think this is the offset checker bug.
> The offset checker will
> 1. first check if the offset exists in offset topic on broker or not.
> 2. If it is on broker then it will just return that offset.
> 3. Otherwise it goes to zookeeper.
>
> So the problem you saw was actually following this logic.
> After dual commit, offset topic already had the offsets for this consumer
> and topic.
> Then you switched to zookeeper commit.
> Because the offset topic has the offsets already, offset checker will use
> that and skip checking zookeeper. So the offset will not change anymore
> because you are no longer committing to offset topic on broker, while
> offset checker always use that offset.
>
> On 2/12/15, 7:30 PM, "tao xiao" <xiaotao...@gmail.com> wrote:
>
> >I used the one shipped with 0.8.2. It is pretty straightforward to
> >reproduce the issue.
> >
> >Here are the steps to reproduce:
> >1. I have a consumer using high level consumer API with initial settings
> >offsets.storage=kafka and dual.commit.enabled=false.
> >2. After consuming messages for a while shutdown the consumer and change
> >setting dual.commit.enabled=true
> >3. bounce the consumer and run for while. The lag looks good
> >4. change setting offsets.storage=zookeeper and bounce the consumer.
> >Starting from now the lag remain unchanged
> >
> >On Fri, Feb 13, 2015 at 11:01 AM, Joel Koshy <jjkosh...@gmail.com> wrote:
> >
> >> That is weird. Are you by any chance running an older version of the
> >> offset checker? Is this straightforward to reproduce?
> >>
> >> On Fri, Feb 13, 2015 at 09:57:31AM +0800, tao xiao wrote:
> >> > Joel,
> >> >
> >> > No, the metric was not increasing. It was 0 all the time.
> >> >
> >> > On Fri, Feb 13, 2015 at 12:18 AM, Joel Koshy <jjkosh...@gmail.com>
> >> wrote:
> >> >
> >> > > Actually I meant to say check that is not increasing.
> >> > >
> >> > > On Thu, Feb 12, 2015 at 08:15:01AM -0800, Joel Koshy wrote:
> >> > > > Possibly a bug - can you also look at the MaxLag mbean in the
> >> consumer
> >> > > > to verify that the maxlag is zero?
> >> > > >
> >> > > > On Thu, Feb 12, 2015 at 11:24:42PM +0800, tao xiao wrote:
> >> > > > > Hi Joel,
> >> > > > >
> >> > > > > When I set dual.commit.enabled=true the count value of both
> >> metrics got
> >> > > > > increased. After I set offsets.storage=zookeeper only
> >> > > ZooKeeperCommitsPerSec
> >> > > > > changed but not KafkaCommitsPerSec. I think this is expected as
> >> kafka
> >> > > > > offset storage was turned off.
> >> > > > >
> >> > > > > But when I looked up the consumer lag via
> >> > > kafka.tools.ConsumerOffsetChecker
> >> > > > > the lag still remained unchanged.
> >> > > > >
> >> > > > > I scanned through the source code of ConsumerOffsetChecker it
> >> doesn't
> >> > > > > check the offset in zk unless offsetFetchResponse returns
> >>NoOffset.
> >> > > Since
> >> > > > > the consumer used kafka as the offset storage before I don't
> >>think
> >> > > > > offsetFetchResponse would return NoOffset
> >> > > > >
> >> > > > > offsetFetchResponse.requestInfo.foreach { case
> >>(topicAndPartition,
> >> > > > > offsetAndMetadata) =>
> >> > > > >
> >> > > > > if (offsetAndMetadata ==
> >>OffsetMetadataAndError.NoOffset) {
> >> > > > >
> >> > > > > val topicDirs = new ZKGroupTopicDirs(group,
> >> > > topicAndPartition.
> >> > > > > topic)
> >> > > > >
> >> > > > > // this group may not have migrated off zookeeper for
> >> offsets
> >> > > > > storage (we don't expose the dual-commit option in this tool
> >> > > > >
> >> > > > > // (meaning the lag may be off until all the consumers
> >> in the
> >> > > > > group have the same setting for offsets storage)
> >> > > > >
> >> > > > > try {
> >> > > > >
> >> > > > > val offset = ZkUtils.readData(zkClient,
> >> > > topicDirs.consumerOffsetDir
> >> > > > > + "/%d".format(topicAndPartition.partition))._1.toLong
> >> > > > >
> >> > > > > offsetMap.put(topicAndPartition, offset)
> >> > > > >
> >> > > > > } catch {
> >> > > > >
> >> > > > > case z: ZkNoNodeException =>
> >> > > > >
> >> > > > >
> >> > > if(ZkUtils.pathExists(zkClient,topicDirs.consumerOffsetDir))
> >> > > > >
> >> > > > > offsetMap.put(topicAndPartition,-1)
> >> > > > >
> >> > > > > else
> >> > > > >
> >> > > > > throw z
> >> > > > >
> >> > > > > }
> >> > > > >
> >> > > > > }
> >> > > > >
> >> > > > > else if (offsetAndMetadata.error ==
> >>ErrorMapping.NoError)
> >> > > > >
> >> > > > > offsetMap.put(topicAndPartition,
> >> offsetAndMetadata.offset)
> >> > > > >
> >> > > > > else {
> >> > > > >
> >> > > > > println("Could not fetch offset for %s due to
> >> %s.".format(
> >> > > > > topicAndPartition,
> >> ErrorMapping.exceptionFor(offsetAndMetadata.error)))
> >> > > > >
> >> > > > > }
> >> > > > >
> >> > > > > }
> >> > > > >
> >> > > > > On Thu, Feb 12, 2015 at 10:03 PM, Joel Koshy
> >><jjkosh...@gmail.com>
> >> > > wrote:
> >> > > > >
> >> > > > > > There are mbeans named KafkaCommitsPerSec and
> >> ZooKeeperCommitsPerSec
> >> > > -
> >> > > > > > can you look those up and see what they report?
> >> > > > > >
> >> > > > > > On Thu, Feb 12, 2015 at 07:32:39PM +0800, tao xiao wrote:
> >> > > > > > > Hi team,
> >> > > > > > >
> >> > > > > > > I was trying to migrate my consumer offset from kafka to
> >> zookeeper.
> >> > > > > > >
> >> > > > > > > Here is the original settings of my consumer
> >> > > > > > >
> >> > > > > > > props.put("offsets.storage", "kafka");
> >> > > > > > >
> >> > > > > > > props.put("dual.commit.enabled", "false");
> >> > > > > > > Here is the steps
> >> > > > > > >
> >> > > > > > > 1. set dual.commit.enabled=true
> >> > > > > > > 2. restart my consumer and monitor offset lag with
> >> > > > > > > kafka.tools.ConsumerOffsetChecker
> >> > > > > > > 3. set offsets.storage=zookeeper
> >> > > > > > > 4. restart my consumer and monitor offset lag with
> >> > > > > > > kafka.tools.ConsumerOffsetChecker
> >> > > > > > >
> >> > > > > > > After step 4 my consumer was able to continually consume
> >>data
> >> from
> >> > > topic
> >> > > > > > > but the offset lag remained unchanged. Did I do anything
> >>wrong?
> >> > > > > > >
> >> > > > > > > --
> >> > > > > > > Regards,
> >> > > > > > > Tao
> >> > > > > >
> >> > > > > >
> >> > > > >
> >> > > > >
> >> > > > > --
> >> > > > > Regards,
> >> > > > > Tao
> >> > > >
> >> > >
> >> > >
> >> >
> >> >
> >> > --
> >> > Regards,
> >> > Tao
> >>
> >>
> >
> >
> >--
> >Regards,
> >Tao
>
>
--
Regards,
Tao
