JEP 158: Unified JVM logging

Wed Aug 15 09:29:49 UTC 2012

Kirk,

Thank you. I'm downloading it.

PS:
Tags vs hierarchy discussion is as old as taxonomy it self.

-Dmitry

On 2012-08-15 13:25, Kirk Pepperdine wrote:
> Hi Dmitry,
> 
> Neal Ford talk is call "Abstraction Distraction".. it's downloadable and
> you can see it here. http://vimeo.com/44235657
> 
> -- Kirk
> 
> On 2012-08-14, at 12:17 PM, Dmitry Samersoff
> <Dmitry.Samersoff at oracle.com <mailto:Dmitry.Samersoff at oracle.com>> wrote:
> 
>> Kirk,
>>
>>> However I do have very serious concerns about this JEP in that it
>>> doesn't fix the problems that exist in current logging frameworks,
>>> it only mimics them.
>>
>>> http://openjdk.java.net/jeps/158
>>
>> Any comments is much appreciated.
>>
>> Personally, I think that log rotation is out of scope and responsibility
>> of JVM.
>>
>> -Dmitry
>>
>>
>> On 2012-08-14 13:26, Kirk Pepperdine wrote:
>>> Hi Yasumasa,
>>>
>>> I'm not sure that log file rotation is a part of this JEP.
>>> However I do have very serious concerns about this JEP in that it
>>> doesn't fix the problems that exist in current logging frameworks, it
>>> only mimics them.
>>>
>>> Regards,
>>> Kirk
>>>
>>> On 2012-08-14, at 11:20 AM, Yasumasa Suenaga
>>> <suenaga.yasumasa at lab.ntt.co.jp
>>> <mailto:suenaga.yasumasa at lab.ntt.co.jp>> wrote:
>>>
>>>> Hi Staffan,
>>>>
>>>> May I ask you 2 questions about this JEP?
>>>>
>>>> 1. One of goals of this JEP is defined as following:
>>>>     "File rotation of log files by size (similar to what is
>>>> available for GC logs today)"
>>>>   My patch realizes log rotation by external trigger.
>>>>   7090324 is included in this JEP?
>>>>   (Is 7090324 included in "Logging can be configured dynamically at
>>>> runtime via jcmd or MBeans" ? )
>>>>
>>>> 2. I've posted a patch for "6950794: Make the GC log file name
>>>> parameterized" .
>>>>     http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2012-July/004758.html
>>>>   Could you include this RFE in this JEP?
>>>>   If we use log rotation, I think that name of logs is very
>>>> important for log management.
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Yasumasa
>>>>
>>>>
>>>> On 2012/08/14 16:50, Staffan Larsen wrote:
>>>>> Hi Yasumasa,
>>>>>
>>>>> This work should be done in the context of the Unified Logging JEP
>>>>> [1]. Unfortunately, that work has not yet started due to resource
>>>>> constraints. Comments on the proposal are welcome.
>>>>>
>>>>> [1] http://openjdk.java.net/jeps/158
>>>>>
>>>>> /Staffan
>>>>>
>>>>> On 31 jul 2012, at 12:45, Yasumasa Suenaga
>>>>> <suenaga.yasumasa at lab.ntt.co.jp
>>>>> <mailto:suenaga.yasumasa at lab.ntt.co.jp>
>>>>> <mailto:suenaga.yasumasa at lab.ntt.co.jp>> wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I've posted a patch for gc log rotation via jinfo tool last year.
>>>>>> Then I received an email that essence of my patch will be
>>>>>> implemented as
>>>>>> "subcommands" of jcmd.
>>>>>>
>>>>>> Now, jcmd is provided by OpenJDK. However, current jcmd does not
>>>>>> seem to
>>>>>> implement function of gclog rotation.
>>>>>>
>>>>>> Will this RFE be implemented?
>>>>>>
>>>>>> I need to rotate gclog which is synchronized with signal, cron,
>>>>>> etc... on Linux.
>>>>>> So, if this RFE is not implemented for a while, I would like to
>>>>>> contribute
>>>>>> patch for jcmd.
>>>>>>
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> Yasumasa
>>>>>>
>>>>>>
>>>>>> On 2011/09/29 21:15, James Melvin wrote:
>>>>>>> Hi Yasumasa,
>>>>>>>
>>>>>>> Thanks very much for your OpenJDK contribution! As part of the
>>>>>>> effort to
>>>>>>> port JRockit features to HotSpot, we plan to introduce a consolidated
>>>>>>> commandline serviceability tool (jcmd) to potentially replace many of
>>>>>>> the existing tools in the bin directory, such as jmap, jstack,
>>>>>>> jinfo and
>>>>>>> others. Over the next few update releases, we plan to add several
>>>>>>> jcmd
>>>>>>> *subcommands* instead to accomplish specific tasks or affect the
>>>>>>> running
>>>>>>> JVM instance. We'd like to use the essence of your contribution
>>>>>>> in one
>>>>>>> of the jcmd subcommands (instead of extending jinfo) to ask the
>>>>>>> JVM to
>>>>>>> begin rotating GC logs. We hope you find this attractive and hope you
>>>>>>> will help review and perfect the change.
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Jim Melvin
>>>>>>> Sr. Engineering Manager
>>>>>>> Oracle
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 9/26/11 6:38 AM, Yasumasa Suenaga wrote:
>>>>>>>> (I've changed subject of this email to new RFE.)
>>>>>>>>
>>>>>>>> This RFE is enhancement of current gclog implementation.
>>>>>>>> So, I'd like to discuss about rotating gclog.
>>>>>>>>
>>>>>>>> My customers need gclog rotation which is invoked by external
>>>>>>>> trigger.
>>>>>>>> So I've requested this RFE and made a patch.
>>>>>>>>
>>>>>>>>
>>>>>>>> In many case on Linux, logfile is rotated by signal (e.g. SIGHUP) .
>>>>>>>> The aim of this RFE is to synchronize gclog and the other logs.
>>>>>>>>
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>>
>>>>>>>> Yasumasa
>>>>>>>>
>>>>>>>> (2011/09/22 20:55), Rainer Jung wrote:
>>>>>>>>> On 22.09.2011 13:20, Dmitry Samersoff wrote:
>>>>>>>>>>
>>>>>>>>>> Yasumasa,
>>>>>>>>>>
>>>>>>>>>> On 2011-09-22 04:47, Yasumasa Suenaga wrote:
>>>>>>>>>>> If we can think Java on Linux and Solaris only, syslog is best
>>>>>>>>>>> solution.
>>>>>>>>>>> However, Windows usually doesn't have syslog.
>>>>>>>>>>>
>>>>>>>>>>> So, I think that gclog is needed for logging GC stats with
>>>>>>>>>>> platform
>>>>>>>>>>> independent in realtime.
>>>>>>>>>>
>>>>>>>>>> Windows has it's own logging API as reach as syslog is or ever
>>>>>>>>>> better
>>>>>>>>>> as well as numerous syslog implementations.
>>>>>>>>>>
>>>>>>>>>> Native windows logging API was completely redesigned for
>>>>>>>>>> Windows 2008
>>>>>>>>>> server and now it allows for developers to send a structured
>>>>>>>>>> events from
>>>>>>>>>> theirs application.
>>>>>>>>>
>>>>>>>>> AFAIK log rotation for loggc is already implemented though not
>>>>>>>>> necessarily yet released. The change discussed here is about
>>>>>>>>> supporting
>>>>>>>>> an externally generated rotation trigger, e.g. via a signal,
>>>>>>>>> instead of
>>>>>>>>> only rotating by size or time via a startup parameter.
>>>>>>>>>
>>>>>>>>> If you want support for syslog or Windows APIs included, it
>>>>>>>>> would be
>>>>>>>>> best to start a new discussion.
>>>>>>>>>
>>>>>>>>> A GC log for an application under load might easily produce a
>>>>>>>>> block of
>>>>>>>>> about 1.5 KB size every few seconds. I seriously doubt, that
>>>>>>>>> the need
>>>>>>>>> for log file rotation can be argued away by referring to syslog or
>>>>>>>>> Windows log API as the correct solution.
>>>>>>>>>
>>>>>>>>> The messages are not really line formatted, the format can vary
>>>>>>>>> a lot
>>>>>>>>> (depending on the excat XX switches), the traffic can be quite
>>>>>>>>> high and
>>>>>>>>> AFAIK the JVM writes it synchronously, so there must be
>>>>>>>>> absolutely no
>>>>>>>>> risk in writing it out with very little latency. In addition, for
>>>>>>>>> analysis, you wouldn't want to look at each event individually, but
>>>>>>>>> instead process the whole file through a script or tool, which
>>>>>>>>> should
>>>>>>>>> not depend on the output specifics of a platform specific log
>>>>>>>>> apparatus.
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>>
>>>>>>>>> Rainer
>>>>>>>>>
>>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>>
>> -- 
>> Dmitry Samersoff
>> Java Hotspot development team, SPB04
>> * There will come soft rains ...
>>
>>
> 

-- 
Dmitry Samersoff
Java Hotspot development team, SPB04
* There will come soft rains ...