RFR: 7164841: Improvements to the GC log file rotation

Yumin Qi yumin.qi at oracle.com
Wed Aug 28 17:34:11 UTC 2013

I really hate to add more flags, though it does not hurt with one more 
since we already have tons of them.
I think if the pattern exists in file name, we can just replace them 
with pid or timestamp so can save a flag:-)


On 8/28/2013 10:30 AM, Tao Mao wrote:
> How about a flag AppendDataAndTimeToGCLogFileName (and default is 
> false) or the like?
> Thanks.
> Tao
> On 8/28/13 9:59 AM, Yumin Qi wrote:
>> Not sure customer really wants to have like
>> -Xloggc:app.log[.%p][.%t]   (whatever the position of %p and %t)
>> at case rotate gc log or not.
>> I can add parsing for name pattern with %p and %t, but that really 
>> needs to have an apprehensive consideration of such change.
>> Any other opinion?
>> Yumin
>> On 8/28/2013 8:30 AM, STIRLING, SCOTT wrote:
>>> Disk overruns can be limited with dedicated log partitions.
>>> Logs can be pre-parsed with command line text tools into separate 
>>> runs, which everyone already has to do for stack traces in system 
>>> out/err logs.
>>> IBM logs work great in PMAT, which also keeps pace with 
>>> ever-evolving parsing nightmare of detailed Hotspot GC logging :-)
>>> Scott
>>> On Aug 28, 2013, at 11:13 AM, "Kirk Pepperdine" <kirk at kodewerk.com> 
>>> wrote:
>>>>> Append vs clobber: with or without rotation, -Xloggc always 
>>>>> clobbers the last log. That's why people want a time stamp or pid 
>>>>> in the gc file name, IMHO.
>>>> My client just clobbered his log files yet... I'd still *not* want 
>>>> the time stamp because this can potentially accidentally fill 
>>>> production disks. Better that my client over wrote the logs than 
>>>> filled his production disk because he didn't realize the behaviour. 
>>>> And, many don't realize the behaviour, they just follow the admin 
>>>> manual.
>>>>> Alternatively, give an option to append when -Xloggc is enabled, 
>>>>> vs default overwrite.
>>>> Allowing an append will break all current analysis tooling.
>>>> Regards,
>>>> Kirk

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