# Resetting the last seen epoch of partition

**URL:** <https://forum.confluent.io/t/resetting-the-last-seen-epoch-of-partition/6740>\
**Category:** Clients\
**Created:** [1 December 2022 15:04 UTC](https://forum.confluent.io/t/resetting-the-last-seen-epoch-of-partition/6740 "2022-12-01T15:04:02Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![FrVaBe](https://avatars.discourse-cdn.com/v4/letter/f/278dde/32.png) [@FrVaBe](https://forum.confluent.io/u/FrVaBe)\
**Post date:** [1 December 2022 15:04 UTC](https://forum.confluent.io/t/resetting-the-last-seen-epoch-of-partition/6740/1 "2022-12-01T15:04:02Z")

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Hi,

we use version 1 of Kafka Mirror Maker to mirror data between systems. I am aware that there is now a version 2, but version 1 is a solid piece of software that does exactly what we need.

We use Kafka Server verison 2.6.x at the moment. However, after updating from Kafka 2.7.x to Kafka 3.3.1 (on the dedicated client / MirrorMaker side - we are still on 2.6.x at the server side), we keep getting the following messages during mirroring from the Mirror Maker process:

```auto
2022-12-01 13:57:45,296 INFO Metadata - [Producer clientId= *****] Resetting the last seen epoch of partition MyTopic-0 to 101 since the associated topicId changed from null to c59OzubzRAO-yhA72TSFEw
2022-12-01 14:02:45,296 INFO Metadata - [Producer clientId= *****] Resetting the last seen epoch of partition MyTopic-0 to 101 since the associated topicId changed from null to c59OzubzRAO-yhA72TSFEw
2022-12-01 14:07:45,298 INFO Metadata - [Producer clientId= *****] Resetting the last seen epoch of partition MyTopic-0 to 101 since the associated topicId changed from null to c59OzubzRAO-yhA72TSFEw
2022-12-01 14:12:45,305 INFO Metadata - [Producer clientId= *****] Resetting the last seen epoch of partition MyTopic-0 to 101 since the associated topicId changed from null to c59OzubzRAO-yhA72TSFEw
2022-12-01 14:17:45,309 INFO Metadata - [Producer clientId= *****] Resetting the last seen epoch of partition MyTopic-0 to 101 since the associated topicId changed from null to c59OzubzRAO-yhA72TSFEw
2022-12-01 14:27:45,317 INFO Metadata - [Producer clientId= *****] Resetting the last seen epoch of partition MyTopic-0 to 101 since the associated topicId changed from null to c59OzubzRAO-yhA72TSFEw

```

MirrorMaker handles hundreds of partitions in our application. The message always appears regularly at 5 (here once at 10) minute intervals - also for other topics and partitions.

Obviously, the message came into the system with a fix to fix KAFKA-12257.

I am now wondering what the message means and whether I can change a configuration to avoid this message. I know that it is only an INFO message, but it still seems to me that I should get to the bottom of the cause.

Can anyone here explain why this message is appearing and what I can do to prevent it. Is there something special about the partitions mentiond?

Thanks in advance,  
Franz

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<div class="post-metadata">

**Author:** ![faizsliet](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.confluent.io/faizsliet/32/3010_2.png) [@faizsliet](https://forum.confluent.io/u/faizsliet)\
**Post date:** [30 May 2023 04:12 UTC](https://forum.confluent.io/t/resetting-the-last-seen-epoch-of-partition/6740/2 "2023-05-30T04:12:10Z")

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These are INFO messages logged in the producer log.

Sample log message as below.

2023-05-05 09:26:29.477 INFO 1 — [ad | producer-1] org.apache.kafka.clients.Metadata : [Producer clientId=producer-1]  
Resetting the last seen epoch of partition topic.name-0 to 6 since the associated topicId changed from null to 6zB3byhITIaqmS6SfM3OQQ

When a client first try to consume/produce from/to a topic, it will initialise an object in memory to track the topic metadata, and upon the first metadata response received from the kafka cluster.It will update its state from the default `null` to the actual topic ID.

If you delete and recreate a topic using the same name, the topic ID will also change and you will see an actual topicId instead of `null` in the message when the client refreshes its metadata.