Thank you so much for all your help. Will keep you posted on tests I do.. I hope this is helpful to other folks too..
On Tue, Oct 15, 2019 at 2:44 PM Ryanne Dolan <ryannedo...@gmail.com> wrote: > That's right. MM2 is at-least-once for now, same as legacy MirrorMaker. You > can follow https://issues.apache.org/jira/browse/KAFKA-6080 for updates on > exactly-once semantics in Connect. > > Ryanne > > On Tue, Oct 15, 2019 at 1:24 PM Vishal Santoshi <vishal.santo...@gmail.com > > > wrote: > > > >> You are correct. I'm working on a KIP and PoC to introduce > > transactions to > > >> Connect for this exact purpose :) > > > > That is awesome. Any time frame ? > > > > > > In the mean time the SLA as of now > > > > 1. It is conceivable that we flush the producer to the target cluster but > > fail to offset commit. If there was a restart before the next successful > > offset commit, there will be duplicates and a part of data is replayed > ( > > at least once ) ? > > > > 2. The same can be said about partial flushes, though am not sure about > > how kafka addresses flush ( Is a flush either success or a failure, and > > nothing in between ) > > > > Thanks.. > > > > On Tue, Oct 15, 2019 at 12:34 PM Ryanne Dolan <ryannedo...@gmail.com> > > wrote: > > > > > Hey Vishal, glad to hear you're making progress. > > > > > > > 1. It seems though that flushing [...] the producer and setting the > > > > offset to the compacting topic is not atomic OR do we use > > > > transactions here ? > > > > > > You are correct. I'm working on a KIP and PoC to introduce transactions > > to > > > Connect for this exact purpose :) > > > > > > > I think these are 4 threads ( b'coz num.tasks=4 ), and I have 2 > topics > > > with > > > > 1 partition each. Do I assume this right, as in there are 4 consumer > > > groups > > > > ( on CG per thread ) ... > > > > > > Some details here: > > > - tasks.max controls the maximum number of tasks created per Connector > > > instance. Both MirrorSourceConnector and MirrorCheckpointConnector will > > > create multiple tasks (up to tasks.max), but MirrorHeartbeatConnector > > only > > > ever creates a single task. Moreover, there cannot be more tasks than > > > topic-partitions (for MirrorSourceConnector) or consumer groups (for > > > MirrorCheckpointConnector). So if you have two topics with one > partition > > > each and 1 consumer group total, you'll have two MirrorSourceConnector > > > tasks, one MirrorHeartbeatConnector task, and one > > MirrorCheckpointConnector > > > tasks, for a total of four. And that's in one direction only: if you > have > > > multiple source->target herders enabled, each will create tasks > > > independently. > > > - There are no consumer groups in MM2, technically. The Connect > framework > > > uses the Coordinator API and internal topics to divide tasks among > > workers > > > -- not a consumer group per se. The MM2 connectors use the assign() > API, > > > not the subscribe() API, so there are no consumer groups there either. > In > > > fact, they don't commit() either. This is nice, as it eliminates a lot > of > > > the rebalancing problems legacy MirrorMaker has been plagued with. With > > > MM2, rebalancing only occurs when the number of workers changes or when > > the > > > assignments change (e.g. new topics are discovered). > > > > > > Ryanne > > > > > > On Tue, Oct 15, 2019 at 10:23 AM Vishal Santoshi < > > > vishal.santo...@gmail.com> > > > wrote: > > > > > > > Hey Ryanne, > > > > > > > > > > > > The test was on topics that had a 7 day retention. Which > > > > generally implies that the batch size for flush is pretty high ( till > > the > > > > consumption becomes current ). The offset.flush.timeout.ms defaults > > to > > > 5 > > > > seconds and the code will not send in the offsets if the flush is not > > > > complete. Increasing that time out did solve the "not sending the > > offset > > > to > > > > topic" issue. > > > > > > > > Two questions ( I am being greedy here :) ) > > > > > > > > 1. It seems though that flushing the flushing the producer and > setting > > > the > > > > offset to the compacting topic is not atomic OR do we use > > > > transactions here ? > > > > > > > > 2. I see > > > > > > > > WorkerSourceTask{id=MirrorHeartbeatConnector-0} flushing 956435 > > > > > > > > WorkerSourceTask{id=MirrorSourceConnector-1} flushing 356251 > > > > > > > > WorkerSourceTask{id=MirrorCheckpointConnector-2} flushing 0 > > > > > > > > WorkerSourceTask{id=MirrorCheckpointConnector-3} flushing 0 > > outstanding > > > > messages > > > > > > > > > > > > I think these are 4 threads ( b'coz num.tasks=4 ), and I have 2 > topics > > > with > > > > 1 partition each. Do I assume this right, as in there are 4 consumer > > > groups > > > > ( on CG per thread ) ... > > > > > > > > > > > > > > > > > > > > > > > > THANKS A LOT > > > > > > > > > > > > Vishal. > > > > > > > > > > > > > > > > On Mon, Oct 14, 2019 at 3:42 PM Ryanne Dolan <ryannedo...@gmail.com> > > > > wrote: > > > > > > > > > > timed out > > > > > while waiting for producer to flush outstanding > > > > > > > > > > Yeah, that's what I'd expect to see if Connect was unable to send > > > records > > > > > to the downstream remote topics, e.g. if min.in-sync.replicas were > > > > > misconfigured. Given some data seems to arrive, it's possible that > > > > > everything is configured correctly but with too much latency to > > > > > successfully commit within the default timeouts. You may want to > > > increase > > > > > the number of tasks substantially to achieve more parallelism and > > > > > throughput. > > > > > > > > > > Ryanne > > > > > > > > > > On Mon, Oct 14, 2019, 2:30 PM Vishal Santoshi < > > > vishal.santo...@gmail.com > > > > > > > > > > wrote: > > > > > > > > > > > Aah no.. this is more to it. Note sure if related to the above. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://github.com/axbaretto/kafka/blob/master/connect/runtime/src/main/java/org/apache/kafka/connect/runtime/SourceTaskOffsetCommitter.java#L114 > > > > > > > > > > > > > > > > > > Is timing out based on > > > > > > > > > > > > > > > > > > > > > > > > > > > https://github.com/axbaretto/kafka/blob/master/connect/runtime/src/main/java/org/apache/kafka/connect/runtime/WorkerConfig.java#L133 > > > > > > > > > > > > [2019-10-14 18:55:20,820] ERROR > > > > > > WorkerSourceTask{id=MirrorSourceConnector-0} Failed to flush, > timed > > > out > > > > > > while waiting for producer to flush outstanding 36478 messages > > > > > > (org.apache.kafka.connect.runtime.WorkerSourceTask:423) > > > > > > > > > > > > > > > > > > > > > > > > On Mon, Oct 14, 2019 at 3:15 PM Vishal Santoshi < > > > > > vishal.santo...@gmail.com > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > I think this might be it.. Could you confirm. It seems to be on > > the > > > > > path > > > > > > > to commit the offsets.. but not sure... > > > > > > > > > > > > > > [2019-10-14 15:29:14,531] ERROR Scheduler for > > MirrorSourceConnector > > > > > > caught > > > > > > > exception in scheduled task: syncing topic ACLs > > > > > > > (org.apache.kafka.connect.mirror.Scheduler:102) > > > > > > > > > > > > > > java.util.concurrent.ExecutionException: > > > > > > > org.apache.kafka.common.errors.SecurityDisabledException: No > > > > Authorizer > > > > > > is > > > > > > > configured on the broker > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > org.apache.kafka.common.internals.KafkaFutureImpl.wrapAndThrow(KafkaFutureImpl.java:45) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > org.apache.kafka.common.internals.KafkaFutureImpl.access$000(KafkaFutureImpl.java:32) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > org.apache.kafka.common.internals.KafkaFutureImpl$SingleWaiter.await(KafkaFutureImpl.java:89) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > org.apache.kafka.common.internals.KafkaFutureImpl.get(KafkaFutureImpl.java:260) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > org.apache.kafka.connect.mirror.MirrorSourceConnector.listTopicAclBindings(MirrorSourceConnector.java:273) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > org.apache.kafka.connect.mirror.MirrorSourceConnector.syncTopicAcls(MirrorSourceConnector.java:214) > > > > > > > > > > > > > > at > > > > > > > > org.apache.kafka.connect.mirror.Scheduler.run(Scheduler.java:93) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > org.apache.kafka.connect.mirror.Scheduler.executeThread(Scheduler.java:112) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > org.apache.kafka.connect.mirror.Scheduler.lambda$scheduleRepeating$0(Scheduler.java:50) > > > > > > > > > > > > > > at > > > > > > > > > > > > java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) > > > > > > > > > > > > > > at > > > > > > > > java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) > > > > > > > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) > > > > > > > > > > > > > > at java.lang.Thread.run(Thread.java:748) > > > > > > > > > > > > > > Caused by: > > > org.apache.kafka.common.errors.SecurityDisabledException: > > > > No > > > > > > > Authorizer is configured on the broker > > > > > > > > > > > > > > On Mon, Oct 14, 2019 at 12:30 PM Ryanne Dolan < > > > ryannedo...@gmail.com > > > > > > > > > > > > wrote: > > > > > > > > > > > > > >> > I do not have a single record in the offsets topic > > > > > > >> > > > > > > >> That's definitely not normal. You are correct that without > > records > > > > in > > > > > > that > > > > > > >> topic, MM2 will restart from EARLIEST. The offsets should be > > > stored > > > > > > >> periodically and whenever the connectors gracefully shutdown > or > > > > > restart. > > > > > > >> > > > > > > >> Is it possible the topics don't have required ACLs or > something? > > > > Also > > > > > > >> note: > > > > > > >> Connect wants the offsets topic to have a large number of > > > partitions > > > > > and > > > > > > >> to > > > > > > >> be compacted. Though I can't imagine either would prevent > > commits > > > > from > > > > > > >> being sent. > > > > > > >> > > > > > > >> Ryanne > > > > > > >> > > > > > > >> On Mon, Oct 14, 2019 at 10:46 AM Vishal Santoshi < > > > > > > >> vishal.santo...@gmail.com> > > > > > > >> wrote: > > > > > > >> > > > > > > >> > 2nd/restore issue ( I think I need to solve the offsets > topic > > > > issue > > > > > > >> > before I go with the scale up and down issue ) > > > > > > >> > > > > > > > >> > As you had indicated, I went ahead and created the offsets > > > topic. > > > > > The > > > > > > >> > status of the cluster ( destination ) is thus > > > > > > >> > > > > > > > >> > opic# Partitions# BrokersBrokers Spread %Brokers Skew > %Brokers > > > > > Leader > > > > > > >> > Skew %# ReplicasUnder Replicated %Leader SizeProducer > > > > > > Message/SecSummed > > > > > > >> > Recent Offsets > > > > > > >> > s8k.checkpoints.internal > > > > > > >> > < > > > > > > >> > > > > > > > > > > > > > > > > > > > > > https://kafka-manager.bf2.tumblr.net/clusters/grete_test/topics/s8k.checkpoints.internal > > > > > > >> > > > > > > > >> > 1 3 60 0 0 3 0 0.00 0 > > > > > > >> > s8k.act_search_page > > > > > > >> > < > > > > > > >> > > > > > > > > > > > > > > > > > > > > > https://kafka-manager.bf2.tumblr.net/clusters/grete_test/topics/s8k.act_search_page > > > > > > >> > > > > > > > >> > 1 3 60 0 0 3 0 6675.30 4,166,842 > > > > > > >> > s8k.act_reach > > > > > > >> > < > > > > > > >> > > > > > > > > > > > > > > > > > > > > > https://kafka-manager.bf2.tumblr.net/clusters/grete_test/topics/s8k.act_reach > > > > > > >> > > > > > > > >> > 1 3 60 0 0 3 0 20657.92 11,579,529 > > > > > > >> > mm2-status.s8k.internal > > > > > > >> > < > > > > > > >> > > > > > > > > > > > > > > > > > > > > > https://kafka-manager.bf2.tumblr.net/clusters/grete_test/topics/mm2-status.s8k.internal > > > > > > >> > > > > > > > >> > 5 5 100 0 0 3 0 0.00 10 > > > > > > >> > mm2-offsets.s8k_test.internal > > > > > > >> > < > > > > > > >> > > > > > > > > > > > > > > > > > > > > > https://kafka-manager.bf2.tumblr.net/clusters/grete_test/topics/mm2-offsets.s8k_test.internal > > > > > > >> > > > > > > > >> > 1 3 60 0 0 3 0 0.00 0 > > > > > > >> > mm2-offsets.s8k.internal > > > > > > >> > < > > > > > > >> > > > > > > > > > > > > > > > > > > > > > https://kafka-manager.bf2.tumblr.net/clusters/grete_test/topics/mm2-offsets.s8k.internal > > > > > > >> > > > > > > > >> > 1 3 60 0 0 3 0 0.00 0 > > > > > > >> > mm2-configs.s8k.internal > > > > > > >> > < > > > > > > >> > > > > > > > > > > > > > > > > > > > > > https://kafka-manager.bf2.tumblr.net/clusters/grete_test/topics/mm2-configs.s8k.internal > > > > > > >> > > > > > > > >> > 1 3 60 0 0 3 0 0.00 13 > > > > > > >> > > > > > > > >> > You can see . that we have the 5 ( I created bot the > offsets, > > > to > > > > be > > > > > > >> safe > > > > > > >> > for the below ) > > > > > > >> > > > > > > > >> > *clusters = s8k, s8k_test* > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > *s8k.bootstrap.servers = .....* > > > > > > >> > > > > > > > >> > *s8k_test.bootstrap.servers = ......* > > > > > > >> > > > > > > > >> > > > > > > > >> > *# only allow replication dr1 -> dr2* > > > > > > >> > > > > > > > >> > *s8k->s8k_test.enabled = true* > > > > > > >> > > > > > > > >> > *s8k->s8k_test.topics = act_search_page|act_reach* > > > > > > >> > > > > > > > >> > *s8k->s8k_test.emit.heartbeats.enabled = false* > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > *s8k_test->s8k.enabled = false* > > > > > > >> > > > > > > > >> > *s8k_test->s8k.emit.heartbeats.enabled = false* > > > > > > >> > > > > > > > >> > *s8k_test.replication.factor = 3* > > > > > > >> > > > > > > > >> > *s8k.replication.factor = 3* > > > > > > >> > > > > > > > >> > *offsets.storage.replication.factor = 3* > > > > > > >> > > > > > > > >> > *replication.factor = 3* > > > > > > >> > > > > > > > >> > *replication.policy.separator = .* > > > > > > >> > > > > > > > >> > *tasks.max = 4* > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > What seems strange is that I do not have a single record in > > the > > > > > > offsets > > > > > > >> > topic.. Is that normal ? I would imagine that without a > > > record, > > > > > > there > > > > > > >> is > > > > > > >> > no way that a restore would happen.... And that is obvious > > when > > > I > > > > > > >> restart > > > > > > >> > the mm2 instance... Find the screenshot attached. In essence > > the > > > > > > latency > > > > > > >> > avg lag is reset \when the mm2 instance is reset indicating > no > > > > > restore > > > > > > >> but > > > > > > >> > restart from EARLIEST... I must be missing some thing simple > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > On Sun, Oct 13, 2019 at 7:41 PM Ryanne Dolan < > > > > ryannedo...@gmail.com > > > > > > > > > > > > >> > wrote: > > > > > > >> > > > > > > > >> >> Vishal, the first issue is easy: you must set tasks.max to > > > > > something > > > > > > >> above > > > > > > >> >> 1 (the default) in order to achieve any parallelism. This > > > > property > > > > > is > > > > > > >> >> passed along to the internal Connect workers. It's > > unfortunate > > > > that > > > > > > >> >> Connect > > > > > > >> >> is not smart enough to default this property to the number > of > > > > > > workers. > > > > > > >> I > > > > > > >> >> suspect that will improve before long. > > > > > > >> >> > > > > > > >> >> For the second issue, is it possible you are missing the > > > offsets > > > > > > >> topic? It > > > > > > >> >> should exist alongside the config and status topics. > Connect > > > > should > > > > > > >> create > > > > > > >> >> this topic, but there are various reasons this can fail, > e.g. > > > if > > > > > the > > > > > > >> >> replication factor is misconfigured. You can try creating > > this > > > > > topic > > > > > > >> >> manually or changing offsets.storage.replication.factor. > > > > > > >> >> > > > > > > >> >> Ryanne > > > > > > >> >> > > > > > > >> >> On Sun, Oct 13, 2019, 5:13 PM Vishal Santoshi < > > > > > > >> vishal.santo...@gmail.com> > > > > > > >> >> wrote: > > > > > > >> >> > > > > > > >> >> > Using > > > > https://github.com/apache/kafka/tree/trunk/connect/mirror > > > > > > as a > > > > > > >> >> > guide, > > > > > > >> >> > I have build from source the origin/KIP-382 of > > > > > > >> >> > https://github.com/apache/kafka.git. > > > > > > >> >> > > > > > > > >> >> > I am seeing 2 issues > > > > > > >> >> > > > > > > > >> >> > * I brought up 2 processes on 2 different nodes ( they > are > > > > > actually > > > > > > >> >> pods on > > > > > > >> >> > k8s but that should not matter ). They share the > > > mm2.properties > > > > > > file > > > > > > >> and > > > > > > >> >> > are replicating ( 1-way ) 3 topics with 8 partitions in > > > total. > > > > > > That > > > > > > >> >> seems > > > > > > >> >> > to be the way to create a standalone mm2 cluster. I do > not > > > > > however > > > > > > >> see( > > > > > > >> >> at > > > > > > >> >> > least the mbeans do not show ) any attempt to rebalance. > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > >> > > > > > > > > > > > > > > > > > > > > > https://github.com/apache/kafka/tree/trunk/connect/mirror#monitoring-an-mm2-process > > > > > > >> >> > mbeans > > > > > > >> >> > are all on a single node > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > * I restart the processes on the 2 nodes ( hard stop ans > > > start > > > > ). > > > > > > The > > > > > > >> >> > offsets for replication seem to be reset to the earliest, > > as > > > if > > > > > it > > > > > > >> is a > > > > > > >> >> > brand new mirroring. It is also obvious from the > > > > > > >> >> > "record-age-ms-avg|replication-latency-ms-avg" > > > > > > >> >> > which I track through the restart. > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > This implies that > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > 1. Load balancing by rebalancing is not working. I cannot > > > scale > > > > > up > > > > > > or > > > > > > >> >> down > > > > > > >> >> > by adding nodes to the mm2 cluster or removing them. > > > > > > >> >> > > > > > > > >> >> > 2. Restore on a mirror is not working. If the MM2 cluster > > is > > > > > > brought > > > > > > >> >> down, > > > > > > >> >> > it does not start mirroring from the last known state. I > > see > > > > the, > > > > > > >> >> > state/config topics etc created as expected.. > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > The mm2.properties is pretty mimimal > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > *clusters = a , b* > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > *a.bootstrap.servers = k.....* > > > > > > >> >> > > > > > > > >> >> > *b.bootstrap.servers = k.....* > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > *# only allow replication dr1 -> dr2* > > > > > > >> >> > > > > > > > >> >> > *a->b.enabled = true* > > > > > > >> >> > > > > > > > >> >> > *a->b.topics = act_search_page* > > > > > > >> >> > > > > > > > >> >> > *a->b.emit.heartbeats.enabled = false* > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > *b->a..enabled = false* > > > > > > >> >> > > > > > > > >> >> > *b->a.emit.heartbeats.enabled = false* > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > What do you think is the issue ? > > > > > > >> >> > > > > > > > >> >> > > > > > > > >> >> > Thanks > > > > > > >> >> > > > > > > > >> >> > > > > > > >> > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > >
