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https://issues.apache.org/jira/browse/EAGLE-97?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15074608#comment-15074608
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Libin, Sun commented on EAGLE-97:
---------------------------------
In GC log monitoring, the key information is stop-the-world event
The following is some sample log from ParaNew GC, CMS GC & G1 GC
{code:title=ParaNew GC sample log}
2014-06-04T22:21:19.158-0700: 9.952: [GC 9.952: [ParNew:
2365777K->5223K(2831168K), 0.0155080 secs] 2365777K->5223K(100348736K),
0.0156030 secs] [Times: user=0.08 sys=0.05, real=0.02 secs]
{code}
{code:title=CMS GC sample log}
2014-06-04T22:47:31.218-0700: 1582.012: [GC [1 CMS-initial-mark:
78942227K(97517568K)] 79264643K(100348736K), 0.2334170 secs] [Times: user=0.23
sys=0.00, real=0.24 secs]
2014-06-04T22:49:50.603-0700: 1721.397: [GC[YG occupancy: 2777944 K (2831168
K)]1721.398: [Rescan (parallel) , 0.1706730 secs]1721.568: [weak refs
processing, 0.0156130 secs] [1 CMS-remark: 83730081K(97517568K)]
86508026K(100348736K), 0.1868130 secs] [Times: user=3.04 sys=0.01, real=0.18
secs]
{code}
{code:title=G1 GC sample log}
0.522: [GC pause (young), 0.15877971 secs]
1.730: [GC pause (mixed), 0.32714353 secs]
[Eden: 12M(12M)->0B(13M) Survivors: 0B->2048K Heap: 14M(64M)->9739K(64M)]
{code}
>From the log, we can extract the key information as the following stream
>definition for alert engine/metric generator to process
{code:title=gc log stream definition}
timestamp long
eventType string
pausedGCTimeSec double
youngAreaGCed boolean
youngUsedHeapK long
youngTotalHeapK long
tenuredAreaGCed boolean
tenuredUsedHeapK long
tenuredTotalHeapK long
permAreaGCed boolean
permUsedHeapK long
permTotalHeapK long
totalHeapUsageAvailable boolean
usedTotalHeapK long
totalHeapK long
logLine string
{code}
> Enable GC Log monitoring for important service like hadoop namenode
> -------------------------------------------------------------------
>
> Key: EAGLE-97
> URL: https://issues.apache.org/jira/browse/EAGLE-97
> Project: Eagle
> Issue Type: New Feature
> Affects Versions: 0.3.0
> Reporter: Libin, Sun
> Assignee: Libin, Sun
>
> Garbage Collection Monitoring refers to the process of figuring out how JVM
> is running GC.
> When GC happened, JVM will stop the application from running to execute a GC,
> every thread except for the threads needed for the GC will stop their tasks.
> The interrupted tasks will resume only after the GC task has completed, the
> stop interval is known as "stop-the-world"
> For service like namenode, GC will affect the performance, especially full
> GC, we should avoid full GC and if full GC happened, we should detected it
> ASAP and sent out alert
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