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Interpreting Concurrent Mark Sweep GC-Log

843829Dec 3 2008 — edited Dec 12 2008
Hi.

I am trying to extract some metrics from the garbage collector log of the concurrent mark sweep garbage collector. I have found a nice walkthrough a this site:
[http://www.sun.com/bigadmin/content/submitted/cms_gc_logs.html |http://www.sun.com/bigadmin/content/submitted/cms_gc_logs.html ]

I'm using CMS in incremental mode and that's where I am having interpretation problems. The site above states that the incremental mode takes over the job of the "concurrent mark"-phase. If this is correct (is it?) that means that I have two different statistics that state how long the "concurrent mark"-phase took. First the incremental CMS statistics and second the ordinary CMS statistics.

The first incremental stats look like this:
2803.125: [GC 2803.125: [ParNew: 408832K->0K(409216K), 0.5371950 secs] 
           611130K->206985K(1048192K) icms_dc=4 , 0.5373720 secs]
2824.209: [GC 2824.209: [ParNew: 408832K->0K(409216K), 0.6755540 secs] 
           615806K->211897K(1048192K) icms_dc=4 , 0.6757740 secs] 
The second ordinary statistics look like this:
40.683: [CMS-concurrent-mark: 0.521/0.529 secs]
I'm wondering wether the second (ordinary) statistics are still valid when using incremental mode.

Kind regards
Frank
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