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https://issues.apache.org/jira/browse/CASSANDRA-8907?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14730751#comment-14730751
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Joshua McKenzie commented on CASSANDRA-8907:
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bq. any unreasonably high GC
While I *personally * agree that 1000ms is unreasonably high, I'd also say that 
I think 500ms is unreasonably high. Or 250ms. Unfortunately there's no single 
right answer for a default value for GC duration on a node and I was thinking 
we err on the side of Least Astonishment.

That being said I'm not married to the idea and I'm core dev, not in ops. For 
the folks in ops reading this - what are your thoughts on a default at 1k vs. 
disabled? cc [~jeromatron] / [~johnny15676] / [~ahattrell]

> Raise GCInspector alerts to WARN
> --------------------------------
>
>                 Key: CASSANDRA-8907
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8907
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Adam Hattrell
>              Labels: patch
>         Attachments: cassnadra-8907.patch
>
>
> I'm fairly regularly running into folks wondering why their applications are 
> reporting down nodes.  Yet, they report, when they grepped the logs they have 
> no WARN or ERRORs listed.
> Nine times out of ten, when I look through the logs we see a ton of ParNew or 
> CMS gc pauses occurring similar to the following:
> INFO [ScheduledTasks:1] 2013-03-07 18:44:46,795 GCInspector.java (line 122) 
> GC for ConcurrentMarkSweep: 1835 ms for 3 collections, 2606015656 used; max 
> is 10611589120
> INFO [ScheduledTasks:1] 2013-03-07 19:45:08,029 GCInspector.java (line 122) 
> GC for ParNew: 9866 ms for 8 collections, 2910124308 used; max is 6358564864
> To my mind these should be WARN's as they have the potential to be 
> significantly impacting the clusters performance as a whole.



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