Hi Andrew & Alex,
Thanks for all your help on this, it's much appreciated.
We have 4 brokers and don't really see this expanding on our platform, would
you recommend a replication factor of 3 or 4 for the __consumer_offsets &
__transaction_state topics, just think about server maintenance and resiliency?
Many Thanks,
Chris
-----Original Message-----
From: Alex Craig <alexcrai...@gmail.com>
Sent: 17 December 2022 13:27
To: users@kafka.apache.org
Subject: Re: __consumer_offsets & __transaction_state topics have
ReplicationFactor: 1
Andrew - your example would give him a replication factor of 2 though, and it
sounds like he wants 3 unless I missed something. So add an additional broker
id to each of the replicas arrays in your example and you'd have an RF of 3.
-alex
On Sat, Dec 17, 2022 at 7:12 AM Andrew Grant <agr...@confluent.io.invalid>
wrote:
> Here's an example with four partitions which should be pretty easily
> extended to include up to partition 49:
> {
> "version": 1,
> "partitions": [
> {
> "topic": "__consumer_offsets",
> "partition": 0,
> "replicas": [ 0, 1 ]
> },
> {
> "topic": "__consumer_offsets",
> "partition": 1,
> "replicas": [ 1, 2 ]
> },
> {
> "topic": "__consumer_offsets",
> "partition": 2,
> "replicas": [ 2, 3 ]
> },
> {
> "topic": "__consumer_offsets",
> "partition": 3,
> "replicas": [ 3, 4 ]
> },
> {
> "topic": "__consumer_offsets",
> "partition": 4,
> "replicas": [ 4, 0 ]
> }
> ]
> }
>
>
> Andrew
>
> On Fri, Dec 16, 2022 at 6:54 PM Chris Peart <ch...@peart.me.uk> wrote:
>
> > Hi Andrew,
> > Would you be able to provide an example of the json with all the
> > partitions in please, I tried this on our dev cluster but it didn’t work.
> > Many Thanks,
> > Chris
> >
> > > On 16 Dec 2022, at 9:03 pm, Andrew Grant
> > > <agr...@confluent.io.invalid>
> > wrote:
> > >
> > > Hey Chris,
> > >
> > > You'd need to do the same for all partitions. I just showed
> > > partition
> 49
> > as
> > > an example - I picked 49 because when I ran a describe it showed
> > > up at
> > the
> > > bottom of my terminal :) You could do all the partitions in the
> > > same reassignment. In that JSON I just put partition 49 but you
> > > could add
> all
> > > the other partitions in it.
> > >
> > > Yeah I'm pretty sure you'd do basically the same for
> > __transaction_state. I
> > > havent tested that myself locally so might be worth doing so on
> > > your
> end.
> > >
> > > Hope that helps a bit.
> > >
> > > Andrew
> > >
> > >> On Fri, Dec 16, 2022 at 11:41 AM Chris Peart <ch...@peart.me.uk>
> wrote:
> > >>
> > >> Hi Andrew,
> > >>
> > >> Thanks for the speedy reply, so do I just need to do this for
> partition
> > >> 49? What about partitions 0-48, will these be covered by
> > >> reassigning partition 49.
> > >>
> > >> Do I need to do this for the __transaction_state topics too?
> > >>
> > >> Many thanks,
> > >> Chris
> > >>
> > >>> On 16 Dec 2022, at 4:17 pm, Andrew Grant
> > >>> <agr...@confluent.io.invalid
> >
> > >> wrote:
> > >>>
> > >>> Hey Chris,
> > >>> I think you should be able to use the reassignment tool to add
> > replicas.
> > >>> You should be able to do something similar to migrate the
> > >>> partitions
> > away
> > >>> from the old brokers and onto the new ones and also increase the
> > >>> replication factor at the same time. I tested just increasing
> > >>> the replication factor with the following commands:
> > >>>
> > >>> kafka % ./bin/kafka-topics.sh --bootstrap-server localhost:9092
> --topic
> > >>> __consumer_offsets --describe | grep 'Partition: 49'
> > >>> Topic: __consumer_offsets Partition: 49 Leader: 1 Replicas: 1
> > >>> Isr: 1
> > >>> Offline:
> > >>>
> > >>> kafka % cat reassignment.json
> > >>> {
> > >>> "version": 1,
> > >>> "partitions": [
> > >>> {
> > >>> "topic": "__consumer_offsets",
> > >>> "partition": 49,
> > >>> "replicas": [ 1, 0 ]
> > >>> }
> > >>> ]
> > >>> }
> > >>>
> > >>> kafka % ./bin/kafka-reassign-partitions.sh --bootstrap-server
> > >>> localhost:9092 --reassignment-json-file reassignment.json
> > >>> --execute Current partition replica assignment
> > >>>
> > >>>
> > >>
> >
> {"version":1,"partitions":[{"topic":"__consumer_offsets","partition":4
> 9,"replicas":[1],"log_dirs":["any"]}]}
> > >>>
> > >>> Save this to use as the --reassignment-json-file option during
> rollback
> > >>> Successfully started partition reassignment for
> > >>> __consumer_offsets-49 kafka % ./bin/kafka-topics.sh
> > >>> --bootstrap-server localhost:9092
> --topic
> > >>> __consumer_offsets --describe | grep 'Partition: 49'
> > >>> Topic: __consumer_offsets Partition: 49 Leader: 1 Replicas: 1,0 Isr:
> > 1,0
> > >>> Offline:
> > >>>
> > >>>
> > >>> Andrew
> > >>>
> > >>>
> > >>>> On Fri, Dec 16, 2022 at 9:46 AM Chris Peart <ch...@peart.me.uk>
> > wrote:
> > >>>>
> > >>>>
> > >>>>
> > >>>> Hi,
> > >>>>
> > >>>> We have a kafka production cluster that was setup with the
> > >>>> defaults
> > for
> > >>>> __consumer_offsets & __transaction_state topics.
> > >>>>
> > >>>> Is there a way to increase the replication factor from 1 to 3
> > >>>> using
> > the
> > >>>> kafka-reassign-partitions tool?
> > >>>>
> > >>>> We are also replacing our 4 brokers with new brokers, this has
> > >>>> been completed so we now have an 8 broker cluster and have
> > >>>> migrated all
> the
> > >>>> topics to the new brokers using the reassign tool except for
> > >>>> the __consumer_offsets & __transaction_state topics.
> > >>>>
> > >>>> We stopped kafka on the old brokers today but all out consumers
> failed
> > >>>> due to the __consumer_offsets & __transaction_state topics
> > >>>> residing
> on
> > >>>> the old brokers.
> > >>>>
> > >>>> I'm thinking we should could move the __consumer_offsets &
> > >>>> __transaction_state topics to the now brokers using the
> > >>>> reassign
> > tool, i
> > >>>> have done this on our dev platform and all is good. If you
> > >>>> think
> this
> > is
> > >>>> good idea we can then can stop kafka on the old nodes and then
> > >>>> work
> on
> > >>>> the replication factoron the new nodes?
> > >>>>
> > >>>> The problem i have is how do we change the replication factor
> > >>>> to 3
> > after
> > >>>> we migrate the __consumer_offsets & __transaction_state topics?
> > >>>>
> > >>>> Thanks in advance.
> > >>>>
> > >>>> Chris
> > >>
> > >>
> >
> >
>
