[
https://issues.apache.org/jira/browse/KAFKA-8270?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jiangtao Liu updated KAFKA-8270:
--------------------------------
Description:
I have a particular blog to explain the whole context at here
[https://medium.com/@jiangtaoliu/a-kafka-pitfall-when-to-set-log-message-timestamp-type-to-createtime-c17846813ca3]
What's the issue?
{quote}There were log segments, which can not be deleted over configured
retention hours.
{quote}
What are impacts?
{quote} # Log space keep in increasing and finally cause space shortage.
# There are lots of log segment rolled with a small size. e.g log segment may
be only 50mb, not the expected 1gb.
# Kafka stream or client may experience missing data.{quote}
How to reproduce it?
#
{quote}Make sure Kafka client and server are not on the same machine.{quote}
#
{quote}Configure log.message.timestamp.type as *CreateTime*, not
LogAppendTime.{quote}
#
{quote}Hack Kafka client's system clock time as a *future time*, e.g
03/04/*2025*, 3:25:52 PM
[GMT-08:00|https://www.epochconverter.com/timezones?q=1741130752]{quote}
#
{quote}Send message from Kafka client to server.{quote}
What's Next?
#
{quote}Check the timestamp in log time index and record in log segment(e.g
00000000035957300794.timeindex). You will see all the timestamp values in
*.timeindex are messed up with a future time after `03/04/*2025*, 3:25:52 PM
[GMT-08:00|https://www.epochconverter.com/timezones?q=1741130752]`.
{quote}
#
{quote}You will also see the new rolled log segment's size smaller than the
configured log segment size after waiting for a while.
{quote}
#
{quote}Log segment (00000000035957300794.log|timeindex) and the rest of new
rolled log segments will not be deleted over retention hours.
{quote}
What's the particular logic to cause this issue?
#
{quote}private def deletableSegments(predicate: (LogSegment,
Option[LogSegment]) =>
Boolean)|[https://github.com/apache/kafka/blob/1.1/core/src/main/scala/kafka/log/Log.scala#L1227]]
will always return empty deletable log segments.{color:#172b4d} {color}
{quote}
was:
What's the issue?
{quote}There were log segments, which can not be deleted over configured
retention hours.
{quote}
What are impacts?
{quote} # Log space keep in increasing and finally cause space shortage.
# There are lots of log segment rolled with a small size. e.g log segment may
be only 50mb, not the expected 1gb.
# Kafka stream or client may experience missing data.{quote}
How to reproduce it?
#
{quote}Configure message.timestamp.type as CreateTime.
{quote}
#
{quote}Reset Kafka client's system clock time as a future time, e.g
03/04/*2025*, 3:25:52 PM
[GMT-08:00|https://www.epochconverter.com/timezones?q=1741130752]
Send message to Kafka.
{quote}
What's Next?
#
{quote}Go to check the timestamp in log time index and record (e.g
00000000035957300794.log|timeindex). You should see all the value of the
timestamp is messed up with future time after `03/04/*2025*, 3:25:52 PM
[GMT-08:00|https://www.epochconverter.com/timezones?q=1741130752]`.
{quote}
#
{quote}You may also see the new rolled log segment's size smaller than the
configured log segment size).
{quote}
#
{quote}Log segment (00000000035957300794.log|timeindex) and any of rolled log
segments will not be deleted.
{quote}
What's the particular logic to cause this issue?
#
{quote}private def deletableSegments(predicate: (LogSegment,
Option[LogSegment]) =>
Boolean)|[https://github.com/apache/kafka/blob/1.1/core/src/main/scala/kafka/log/Log.scala#L1227]]
will always return empty deletable log segments.
{quote}
> Kafka timestamp-based retention policy is not working when Kafka client's
> time is not reliable.
> -----------------------------------------------------------------------------------------------
>
> Key: KAFKA-8270
> URL: https://issues.apache.org/jira/browse/KAFKA-8270
> Project: Kafka
> Issue Type: Bug
> Components: log, log cleaner, logging
> Affects Versions: 1.1.1
> Reporter: Jiangtao Liu
> Priority: Major
> Labels: storage
> Attachments: Screen Shot 2019-04-20 at 10.57.59 PM.png
>
>
> I have a particular blog to explain the whole context at here
> [https://medium.com/@jiangtaoliu/a-kafka-pitfall-when-to-set-log-message-timestamp-type-to-createtime-c17846813ca3]
> What's the issue?
> {quote}There were log segments, which can not be deleted over configured
> retention hours.
> {quote}
> What are impacts?
> {quote} # Log space keep in increasing and finally cause space shortage.
> # There are lots of log segment rolled with a small size. e.g log segment
> may be only 50mb, not the expected 1gb.
> # Kafka stream or client may experience missing data.{quote}
> How to reproduce it?
> #
> {quote}Make sure Kafka client and server are not on the same machine.{quote}
> #
> {quote}Configure log.message.timestamp.type as *CreateTime*, not
> LogAppendTime.{quote}
> #
> {quote}Hack Kafka client's system clock time as a *future time*, e.g
> 03/04/*2025*, 3:25:52 PM
> [GMT-08:00|https://www.epochconverter.com/timezones?q=1741130752]{quote}
> #
> {quote}Send message from Kafka client to server.{quote}
> What's Next?
> #
> {quote}Check the timestamp in log time index and record in log segment(e.g
> 00000000035957300794.timeindex). You will see all the timestamp values in
> *.timeindex are messed up with a future time after `03/04/*2025*, 3:25:52 PM
> [GMT-08:00|https://www.epochconverter.com/timezones?q=1741130752]`.
> {quote}
> #
> {quote}You will also see the new rolled log segment's size smaller than the
> configured log segment size after waiting for a while.
> {quote}
> #
> {quote}Log segment (00000000035957300794.log|timeindex) and the rest of new
> rolled log segments will not be deleted over retention hours.
> {quote}
> What's the particular logic to cause this issue?
> #
> {quote}private def deletableSegments(predicate: (LogSegment,
> Option[LogSegment]) =>
> Boolean)|[https://github.com/apache/kafka/blob/1.1/core/src/main/scala/kafka/log/Log.scala#L1227]]
> will always return empty deletable log segments.{color:#172b4d} {color}
> {quote}
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