What is the size of your new gen?  Is it growing?  Does it level off?
St.Ack

On Mon, May 16, 2011 at 12:39 PM, Jack Levin <[email protected]> wrote:
> There HEAP would be 8G used out of 12G total.  The gc-log would be
> full of ParNew, no FULL GC at all, ParNew just starts at hight rate
> (10-15 lines per second).  Even if you remove queries, the JVM will
> not recover, and user CPU will remain 100%.  Only thing left to do is
> to kill the process.  We are not writing in nearly as fast to case
> such an issue.  This looks like a systemic problem, e.g. low enough
> load when it comes to QPS, and the problem effectively kills HBASE.
> There should be a way to tune things so that ParNew does not jump to
> an inappropriate levels.
>
> -Jack
>
> On Mon, May 16, 2011 at 12:02 PM, Stack <[email protected]> wrote:
>> On Sun, May 15, 2011 at 5:37 PM, Jack Levin <[email protected]> wrote:
>>> I've added occupancy:  export HBASE_OPTS="$HBASE_OPTS -verbose:gc
>>> -XX:CMSInitiatingOccupancyFraction=70 -XX:+PrintGCDetails
>>> -XX:+PrintGCDateStamps -XX:+HeapDumpOnOutOfMemoryError
>>> -Xloggc:$HBASE_HOME/logs/gc-hbase.log"
>>>
>>
>> Does the big CPU usage correlate to a Full GC?  Do you  notice that in
>> your logs Jack?
>>
>> I took a look at your thread dumps.  Nothing untoward (blocking on hdfs 
>> access).
>>
>> St.Ack
>>
>

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