Thanks Miguel, I did that
Based on the following Json file
{
"version":1,
"partitions":[
{"topic":"md","partition":0,"replicas":[1,3,7]},
{"topic":"md","partition":1,"replicas":[2,8,9]},
{"topic":"md","partition":2,"replicas":[7,10,12]}
]
}
I ran this command
kafka-reassign-partitions.sh --bootstrap-server rhes75:9092
--reassignment-json-file ./reduce_replication_factor2.json --execute
Current partition replica assignment
{"version":1,"partitions":[{"topic":"md","partition":0,"replicas":[1,3,7],"log_dirs":["any","any","any"]},{"topic":"md","partition":1,"replicas":[2,8,9],"log_dirs":["any","any","any"]},{"topic":"md","partition":2,"replicas":[7,10,12],"log_dirs":["any","any","any"]}]}
Save this to use as the --reassignment-json-file option during rollback
Successfully started partition reassignments for md-0,md-1,md-2
kafka-topics.sh --describe --bootstrap-server rhes75:9092 --topic md
Topic: md TopicId: UfQly87bQPCbVKoH-PQheg PartitionCount: 9
ReplicationFactor: 3 Configs: segment.bytes=1073741824,retention.ms
=1000,retention.bytes=1073741824
Topic: md Partition: 0 Leader: 1 Replicas: 1,3,7
Isr: 1,3,7
Topic: md Partition: 1 Leader: 2 Replicas: 2,8,9
Isr: 2,8,9
Topic: md Partition: 2 Leader: 7 Replicas: 7,10,12
Isr: 10,7,12
Topic: md Partition: 3 Leader: 1 Replicas:
1,12,9,11,7,3,10,8,2 Isr: 10,1,9,2,12,7,3,11,8
Topic: md Partition: 4 Leader: 7 Replicas:
7,9,11,1,3,10,8,2,12 Isr: 10,1,9,2,12,7,3,11,8
Topic: md Partition: 5 Leader: 3 Replicas:
3,11,1,7,10,8,2,12,9 Isr: 10,1,9,2,12,7,3,11,8
Topic: md Partition: 6 Leader: 10 Replicas:
10,1,7,3,8,2,12,9,11 Isr: 10,1,9,2,12,7,3,11,8
Topic: md Partition: 7 Leader: 8 Replicas:
8,7,3,10,2,12,9,11,1 Isr: 10,1,9,2,12,7,3,11,8
Topic: md Partition: 8 Leader: 2 Replicas:
2,3,10,8,12,9,11,1,7 Isr: 10,1,9,2,12,7,3,11,8
Mich
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<https://www.linkedin.com/in/mich-talebzadeh-ph-d-5205b2/>
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On Wed, 17 May 2023 at 00:21, Miguel A. Sotomayor <masfwo...@gmail.com>
wrote:
> Hi Mich,
>
> You can use the script `kafka-reassign-partitions.sh` to re-locate or
> change the number of replicas
>
> Regards
> Miguel
>
> El mar, 16 may 2023 a las 18:44, Mich Talebzadeh (<
> mich.talebza...@gmail.com>)
> escribió:
>
> > Thanks Peter. I meant reduce replication from 9 to 3 and Not partitions.
> > Apologies for any confusion
> >
> >
> > Cheers
> >
> > *Disclaimer:* Use it at your own risk. Any and all responsibility for any
> > loss, damage or destruction of data or any other property which may arise
> > from relying on this email's technical content is explicitly disclaimed.
> > The author will in no case be liable for any monetary damages arising
> from
> > such loss, damage or destruction.
> >
> >
> >
> >
> > On Tue, 16 May 2023 at 17:38, Peter Bukowinski <pmb...@gmail.com> wrote:
> >
> > > Mich,
> > >
> > > It is not possible to reduce the number of partitions for a kafka topic
> > > without deleting and recreating the topic. What previous responders to
> > your
> > > inquiry noted is that your topic replication of 9 is high. What you
> want
> > to
> > > do is reduce your replication, not the partitions. You can do this
> using
> > > the same json file you had the first time, with all 9 partitions. Just
> > > remove 6 of the 9 broker ids from the replicas array, e.g.
> > >
> > > cat reduce_replication_factor.json
> > > {
> > > "version":1,
> > > "partitions":[
> > > {"topic":"md","partition":0,"replicas":[12,10,8]},
> > > {"topic":"md","partition":1,"replicas":[9,8,2]},
> > > {"topic":"md","partition":2,"replicas":[11,2,12]},
> > > {"topic":"md","partition":3,"replicas":[1,12,9]},
> > > {"topic":"md","partition":4,"replicas":[7,9,11]},
> > > {"topic":"md","partition":5,"replicas":[3,11,1]}
> > > ]
> > > }
> > >
> > > You may want to adjust where the replicas sit to achieve a better
> balance
> > > across the cluster, but this arrangement only truncates the last 6
> > replicas
> > > from the list, so should complete quickly as no replica data would
> move,
> > > only be deleted.
> > >
> > > —
> > > Peter Bukowinski
> > >
> > >
> > >
> > > > On May 12, 2023, at 1:24 PM, Mich Talebzadeh <
> > mich.talebza...@gmail.com>
> > > wrote:
> > > >
> > > > My bad. Only need 3 partitions
> > > >
> > > > {
> > > > "version":1,
> > > > "partitions":[
> > > > {"topic":"md","partition":0,"replicas":[12,10,8,2,9,11,1,7,3]},
> > > > {"topic":"md","partition":1,"replicas":[9,8,2,12,11,1,7,3,10]},
> > > > {"topic":"md","partition":2,"replicas":[11,2,12,9,1,7,3,10,8]}
> > > > ]
> > > > }
> > > >
> > > > Mich Talebzadeh,
> > > > Lead Solutions Architect/Engineering Lead
> > > > Palantir Technologies Limited
> > > > London
> > > > United Kingdom
> > > >
> > > >
> > > > view my Linkedin profile
> > > > <https://www.linkedin.com/in/mich-talebzadeh-ph-d-5205b2/>
> > > >
> > > >
> > > > https://en.everybodywiki.com/Mich_Talebzadeh
> > > >
> > > >
> > > >
> > > > *Disclaimer:* Use it at your own risk. Any and all responsibility for
> > any
> > > > loss, damage or destruction of data or any other property which may
> > arise
> > > > from relying on this email's technical content is explicitly
> > disclaimed.
> > > > The author will in no case be liable for any monetary damages arising
> > > from
> > > > such loss, damage or destruction.
> > > >
> > > >
> > > >
> > > >
> > > > On Fri, 12 May 2023 at 21:18, Mich Talebzadeh <
> > mich.talebza...@gmail.com
> > > >
> > > > wrote:
> > > >
> > > >> This json file seemed to work
> > > >>
> > > >> cat reduce_replication_factor.json
> > > >> {
> > > >> "version":1,
> > > >> "partitions":[
> > > >> {"topic":"md","partition":0,"replicas":[12,10,8,2,9,11,1,7,3]},
> > > >> {"topic":"md","partition":1,"replicas":[9,8,2,12,11,1,7,3,10]},
> > > >> {"topic":"md","partition":2,"replicas":[11,2,12,9,1,7,3,10,8]},
> > > >> {"topic":"md","partition":3,"replicas":[1,12,9,11,7,3,10,8,2]},
> > > >> {"topic":"md","partition":4,"replicas":[7,9,11,1,3,10,8,2,12]},
> > > >> {"topic":"md","partition":5,"replicas":[3,11,1,7,10,8,2,12,9]}
> > > >> ]
> > > >> }
> > > >>
> > > >> kafka-reassign-partitions.sh --bootstrap-server
> > > >>
> > >
> >
> rhes75:9092,rhes75:9093,rhes75:9094,rhes76:9092,rhes76:9093,rhes76:9094,rhes76:9095,rhes76:9096,
> > > >> rhes76:9097 --reassignment-json-file
> ./reduce_replication_factor.json
> > > >> --execute
> > > >>
> > > >> The output
> > > >>
> > > >> Successfully started partition reassignments for
> > > >> md-0,md-1,md-2,md-3,md-4,md-5
> > > >>
> > > >>
> > > >> I guess it is going to take sometime before it is completed.
> > > >>
> > > >> Thanks
> > > >>
> > > >>
> > > >>
> > > >>
> > > >> On Fri, 12 May 2023 at 20:16, Mich Talebzadeh <
> > > mich.talebza...@gmail.com>
> > > >> wrote:
> > > >>
> > > >>> Thanks Matthias.
> > > >>>
> > > >>> with regard to your point below:
> > > >>>
> > > >>> A replication factor of 9 sounds very high. For production, a
> > > replication
> > > >>> factor of 3 is recommended.
> > > >>>
> > > >>> Is it possible to dynamically reduce this number to 3 when the
> topic
> > is
> > > >>> actively consumed)?
> > > >>>
> > > >>>
> > > >>>
> > > >>> *Disclaimer:* Use it at your own risk. Any and all responsibility
> for
> > > >>> any loss, damage or destruction of data or any other property which
> > may
> > > >>> arise from relying on this email's technical content is explicitly
> > > >>> disclaimed. The author will in no case be liable for any monetary
> > > damages
> > > >>> arising from such loss, damage or destruction.
> > > >>>
> > > >>>
> > > >>>
> > > >>>
> > > >>> On Fri, 12 May 2023 at 19:38, Matthias J. Sax <mj...@apache.org>
> > > wrote:
> > > >>>
> > > >>>>> Does having 9 partitions with 9 replication factors make sense
> > here?
> > > >>>>
> > > >>>> A replication factor of 9 sounds very high. For production,
> > > replication
> > > >>>> factor of 3 is recommended.
> > > >>>>
> > > >>>> How many partitions you want/need is a different question, and
> > cannot
> > > be
> > > >>>> answered in a general way.
> > > >>>>
> > > >>>>
> > > >>>> "Yes" to all other questions.
> > > >>>>
> > > >>>>
> > > >>>> -Matthias
> > > >>>>
> > > >>>>
> > > >>>>
> > > >>>> On 5/12/23 9:50 AM, Mich Talebzadeh wrote:
> > > >>>>> Hi,
> > > >>>>>
> > > >>>>> I have used Apache Kafka in conjunction with Spark as a messaging
> > > >>>>> source. This rather dated diagram describes it
> > > >>>>>
> > > >>>>> I have two physical hosts each 64 GB, running RHES 7.6, these are
> > > >>>> called
> > > >>>>> rhes75 and rhes76 respectively. The Zookeeper version is 3.7.1
> and
> > > >>>> kafka
> > > >>>>> version is 3.4.0
> > > >>>>>
> > > >>>>>
> > > >>>>> image.png
> > > >>>>> I have a topic md -> MarketData that has been defined as below
> > > >>>>>
> > > >>>>> kafka-topics.sh --create --bootstrap-server
> > > >>>>>
> > > >>>>
> > >
> >
> rhes75:9092,rhes75:9093,rhes75:9094,rhes76:9092,rhes76:9093,rhes76:9094,rhes76:9095,rhes76:9096,
> > > >>>> rhes76:9097 --replication-factor 9 --partitions 9 --topic md
> > > >>>>>
> > > >>>>> kafka-topics.sh --describe --bootstrap-server
> > > >>>>>
> > > >>>>
> > >
> >
> rhes75:9092,rhes75:9093,rhes75:9094,rhes76:9092,rhes76:9093,rhes76:9094,rhes76:9095,rhes76:9096,
> > > >>>> rhes76:9097 --topic md
> > > >>>>>
> > > >>>>>
> > > >>>>> This is working fine
> > > >>>>>
> > > >>>>> Topic: md TopicId: UfQly87bQPCbVKoH-PQheg PartitionCount: 9
> > > >>>>
> > > >>>>> ReplicationFactor: 9 Configs: segment.bytes=1073741824
> > > >>>>> Topic: md Partition: 0 Leader: 12 Replicas:
> > > >>>>> 12,10,8,2,9,11,1,7,3 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>> Topic: md Partition: 1 Leader: 9 Replicas:
> > > >>>>> 9,8,2,12,11,1,7,3,10 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>> Topic: md Partition: 2 Leader: 11 Replicas:
> > > >>>>> 11,2,12,9,1,7,3,10,8 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>> Topic: md Partition: 3 Leader: 1 Replicas:
> > > >>>>> 1,12,9,11,7,3,10,8,2 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>> Topic: md Partition: 4 Leader: 7 Replicas:
> > > >>>>> 7,9,11,1,3,10,8,2,12 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>> Topic: md Partition: 5 Leader: 3 Replicas:
> > > >>>>> 3,11,1,7,10,8,2,12,9 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>> Topic: md Partition: 6 Leader: 10 Replicas:
> > > >>>>> 10,1,7,3,8,2,12,9,11 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>> Topic: md Partition: 7 Leader: 8 Replicas:
> > > >>>>> 8,7,3,10,2,12,9,11,1 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>> Topic: md Partition: 8 Leader: 2 Replicas:
> > > >>>>> 2,3,10,8,12,9,11,1,7 Isr: 10,1,9,2,12,7,3,11,8
> > > >>>>>
> > > >>>>> However, I have a number of questions
> > > >>>>>
> > > >>>>> 1. Does having 9 partitions with 9 replication factors make
> sense
> > > >>>> here?
> > > >>>>> 2. As I understand the parallelism is equal to the number of
> > > >>>> partitions
> > > >>>>> for a topic.
> > > >>>>> 3. Kafka only provides a total order over messages *within a
> > > >>>>> partition*, not between different partitions in a topic and in
> > > >>>>> this case I have one topic
> > > >>>>> 4.
> > > >>>>>
> > > >>>>> Data within a Partition will be stored in the order in which
> it
> > is
> > > >>>>> written, therefore, data read from a Partition will be read in
> > > >>>> order
> > > >>>>> for that partition?
> > > >>>>>
> > > >>>>> 5.
> > > >>>>>
> > > >>>>> Finally if I want to get messages in order across multiple
> all 9
> > > >>>>> partitionss, then I need to group messages with a key, so that
> > > >>>>> messages with the samekey goto the samepartition and
> withinthat
> > > >>>>> partition the messages are ordered
> > > >>>>>
> > > >>>>> Thanks
> > > >>>>>
> > > >>>>>
> > > >>>>> *Disclaimer:* Use it at your own risk.Any and all responsibility
> > for
> > > >>>> any
> > > >>>>> loss, damage or destruction of data or any other property which
> may
> > > >>>>> arise from relying on this email's technical content is
> explicitly
> > > >>>>> disclaimed. The author will in no case be liable for any monetary
> > > >>>>> damages arising from such loss, damage or destruction.
> > > >>>>>
> > > >>>>
> > > >>>
> > >
> > >
> >
>
>
> --
>
>
> Saludos.
> Miguel Ángel
>
