Question about Object Copy times

[D vd Reddy]

Oh sorry for the mistake in the throughput definition,

The options we were using were just setting MaxGCPause to 1000ms, here is
the exhaustive list
"-XX:+AggressiveOpts -XX:InitialHeapSize=154618822656 -XX:+ManagementServer
-XX:MaxGCPauseMillis=1000 -XX:MaxHeapSize=154618822656
-XX:MaxMetaspaceSize=268435456 -XX:MetaspaceSize=268435456
-XX:ObjectAlignmentInBytes=16 -XX:+PrintAdaptiveSizePolicy -XX:+PrintGC
-XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintTenuringDistribution
-XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions
-XX:-UseCompressedOops -XX:+UseG1GC "

The numbers we were seeing in other applications (one is HBase)  were close
to 99 % , that's when we took a look in the GC logs to see if there is
anything more we can extract, the only thing that caught our eye was the
high object copy times which we did not see in the other applications.

Thanks for the help and suggestions.


On Mon, Aug 24, 2015 at 12:54 PM, Tao Mao <yiyeguhu at gmail.com> wrote:

> You are almost correct: this throughput number is defined as the ratio of
> user application time to the total run time, i.e., 100% is the "ideal"
>
> From your reporting, ~97% is the best result so far. It's near the limit.
> If you don't have a particular reason to push further, you can walk away
> with your current tuning. Can you post the JVM options for your best run?
>
> Thanks.
> Tao Mao
>
>
> On Mon, Aug 24, 2015 at 12:28 PM, D vd Reddy <dvdeepankar.reddy at gmail.com>
> wrote:
>
>> This is the number given out by GCViewer, it is the ratio of time spent
>> in GC to total time of the JVM running.
>>
>>
>>
>>
>> Thanks
>>
>>
>> On Mon, Aug 24, 2015 at 12:15 PM, Yu Zhang <yu.zhang at oracle.com> wrote:
>>
>>> Reddy,
>>>
>>> Can you explain how you measure the throughput? For example, what does
>>> it mean 'throughput of 92%'?
>>>
>>> Thanks,
>>> Jenny
>>>
>>> On 8/24/2015 12:05 PM, D vd Reddy wrote:
>>>
>>> I made a couple of experiments run over the weekend, first I ran a
>>> experiment with lowering the maxGCPause it did help, lowered the throughput
>>> to 92%.
>>>
>>>
>>>
>>
>
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