[
https://issues.apache.org/jira/browse/IGNITE-15460?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17416450#comment-17416450
]
Alexey Kukushkin commented on IGNITE-15460:
-------------------------------------------
Closing the issue without a fix: discussed the issues with the community and
there were different opinions where this should be fixed. Some agree with
removing the suggestion but others think it is a good practice to always
specify {{MaxDirectMemorySize}}, as well as max heap size ({{-Xmx}}) and
off-heap size (sum of {{DataRegionConfiguration.maxSize}}) to make it explicit
that the total Ignite JVM memory does not exceed physical RAM that could be
allocated to the JVM process.
> Incorrect "Set max direct memory size" suggestion
> -------------------------------------------------
>
> Key: IGNITE-15460
> URL: https://issues.apache.org/jira/browse/IGNITE-15460
> Project: Ignite
> Issue Type: Improvement
> Affects Versions: 2.10
> Reporter: Alexey Kukushkin
> Priority: Major
>
> Ignite always outputs this performance suggestion on startup:
> {{Set max direct memory size if getting 'OOME: Direct buffer memory' (add
> '-XX:MaxDirectMemorySize=<size>[g|G|m|M|k|K]' to JVM options)}}
>
> That is incorrect since:
> * The Ignite [Memory and JVM
> Tuning|https://ignite.apache.org/docs/latest/perf-and-troubleshooting/memory-tuning#memory-and-jvm-tuning]
> page suggests NOT to explicitly set the {{MaxDirectMemorySize}} (unless
> native persistence is used but in this case set it to {{walSegmentSize *
> 4}}). Not setting {{MaxDirectMemorySize}} seems the right default option
> since in this case JVM would choose the most appropriate default size.
> * Increasing direct memory size when getting OOME for direct memory seems
> too obvious to always print this information.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
