[
https://issues.apache.org/jira/browse/HADOOP-19461?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17929953#comment-17929953
]
ASF GitHub Bot commented on HADOOP-19461:
-----------------------------------------
chaijunjie0101 commented on PR #7406:
URL: https://github.com/apache/hadoop/pull/7406#issuecomment-2680168151
> Sorry, the PR title is misleading, I think the current trunk code could
report "Total GC Count" and "Total GC time in milliseconds" correctly for
Generational ZGC without this patch, and the implementation does not look
correct to me.
>
> Minor and Major GC are quite common concepts for GC, not specific to ZGC,
for example, the [Spark
docs](https://spark.apache.org/docs/latest/monitoring.html) say:
>
> > .MinorGCCount - Total minor GC count. For example, the garbage collector
is one of Copy, PS Scavenge, ParNew, G1 Young Generation and so on.
> > .MajorGCCount - Total major GC count. For example, the garbage collector
is one of MarkSweepCompact, PS MarkSweep, ConcurrentMarkSweep, G1 Old
Generation and so on.
hi, thanks reviwing~
I used JDK 21(https://gitee.com/openeuler/bishengjdk-21), you are right, but
for different GC, **has different bean name** for minor/Major GC, I just found
Generational ZGC use MajorGC/MinorGC directly, but for example CMS GC:
jmx["java.lang:type=GarbageCollector,name=ParNew","CollectionCount"]
jmx["java.lang:type=GarbageCollector,name=ParNew","CollectionTime"]
jmx["java.lang:type=GarbageCollector,name=ConcurrentMarkSweep","CollectionCount"]
jmx["java.lang:type=GarbageCollector,name=ConcurrentMarkSweep","CollectionTime"]
ParNew likely Minor GC, ConcurrentMarkSweep likely Major GC, but I do not
why they not use same bean name like "MajorGC", maybe some diiferent here?
when I test on JDK21, I just want get a more refined GC time to adjust
Youg/Old memory size, since ZGC provides them(Major/Minor), we could fetch
them...
you means we no need it, or need to support all GC's "MajorGC/MinorGC", but
it may be difficult, the JDK not define a common metric for them?
> JVM GC Metrics supports Generational ZGC pause time
> ---------------------------------------------------
>
> Key: HADOOP-19461
> URL: https://issues.apache.org/jira/browse/HADOOP-19461
> Project: Hadoop Common
> Issue Type: Improvement
> Reporter: chaijunjie
> Priority: Major
> Labels: pull-request-available
> Attachments: HADOOP-19461.JPG, HADOOP-19461.patch
>
>
> See [https://bugs.openjdk.org/browse/JDK-8307059] , The Generational ZGC
> separate the Cycles and Pauses as Minor and Major,like this:
> * Old ZGC: "ZGC Cycles", "ZGC Pauses"
> * Generational ZGC: "ZGC Minor Cycles", "ZGC Minor Pauses", "ZGC Major
> Cycles", "ZGC Major Pauses"
> let us separate it same and give 2 new metric about these, may be better...
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
