Request for review: 6941923: RFE: Handling large log files produced by long running Java Applications

[Y. S. Ramakrishna]

A possibility to pursue:

You could make the appropriate flags manageable, and re-sample/re-snapshot
into private variable (and when appropriate re-initialize the streams)
at each safepoint where you now just check for log rotation.

-- ramki

On 04/13/11 09:54, yumin.qi at oracle.com wrote:
>  Current implementation will not work with outside tool, ostream_init 
> called once in JVM starting and flags will not be changed rest of 
> running supposedly. Now need to think of what if flags changed by 
> outside tool.  Need reconsideration of changing flags from outside tool.
> 
> Thanks
> Yumin
> 
> On 4/13/2011 8:47 AM, Jon Masamitsu wrote:
>> Yasumasa ,
>>
>> Sounds like this is a request for an enhancement of the
>> feature that Yumin has implemented.   Or rather maybe
>> just a way of turning it on?  Or is it something more basic
>> to the feature?
>>
>> Jon
>>
>> On 4/12/2011 5:55 PM, Yasumasa Suenaga wrote:
>>> Hi Yumin,
>>>
>>> I would like to rotate GC log triggered by the outside.
>>> I think that it can be implemented using AttachLister 
>>> (AttachOperationFunctionInfo [])
>>> and invoker tool.
>>>
>>> Could you examine it?
>>>
>>>
>>> Best regards,
>>>
>>> Yasumasa
>>>
>>> (2011/04/13 3:41), yumin.qi at oracle.com wrote:
>>>> http://cr.openjdk.java.net/~minqi/6941923/webrev.00/ 
>>>> <http://cr.openjdk.java.net/%7Eminqi/6941923/webrev.00/>
>>>>
>>>> Summary:
>>>>
>>>> This is a RFE request for having a GC log rotation to prevent Java 
>>>> application from over flooding disk with GC output running for long 
>>>> time.
>>>> In the implementation, supply three JVM options
>>>> 1) -XX:+UseGCLogFileRotation must be used with -Xloggc:file
>>>> 2) -XX:MaxGCLogFileNumbers= set limit of rotation file numbers, 
>>>> default to 1, maximum set to 1024.
>>>> 3) -XX:GCLogFileSize= can be configured by user how big the file 
>>>> size should be. Default to 10M. Minimum set to 512K if given from 
>>>> option is less than 512K.
>>>>
>>>> If MaxGCLogFileNumbers=1, rotating output in same file, i.e write 
>>>> from beginning of the file when reach cap of the file; with 
>>>> MaxGCLogFileNumbers > 1 rotating files sequentially after reach cap 
>>>> in file, file.1, file.2, ..., file.<MaxGCLogFileNumbers-1> then back 
>>>> to file, file.1, ...
>>>> Check if rotation needed at safepoint ending.
>>>>
>>>> Tested with multiple GC choices.
>>>>
>>>> Thanks
>>>> Yumin
>>>>
>>>>
>>>>