RFR: 8146879: Add option for handling existing log files in UL

[Marcus Larsson]

Thanks for reviewing, Robbin!

Marcus

On 03/22/2016 03:24 PM, Robbin Ehn wrote:
> Hi Marcus,
>
> On 03/18/2016 02:04 PM, Marcus Larsson wrote:
>> Updated patch after feedback.
>>
>> New webrev:
>> http://cr.openjdk.java.net/~mlarsson/8146879/webrev.04/
>>
>> Incremental:
>> http://cr.openjdk.java.net/~mlarsson/8146879/webrev.03-04/
>>
>> Tested with internal VM tests through RBT.
>>
>> Changes:
>> * Rotation filecount is now limited to 1000 files.
>> * Removed loop in os::compare_file_modified_times.
>> * Added a check before rotating/truncating an existing log file, and
>> will only do so if it's a regular file.
>> * Added test case to check that logging to a directory gives the
>> intended error message.
>> * Fixed test help method to handle arbitrary length log lines.
>
> I tested this and it works fine.
>
> Code looks good to me.
>
> Thanks for fixing this!
>
> /Robbin
>
>>
>> Thanks,
>> Marcus
>>
>> On 03/11/2016 03:21 PM, Marcus Larsson wrote:
>>> Third time's the charm.
>>>
>>> Webrev:
>>> http://cr.openjdk.java.net/~mlarsson/8146879/webrev.03/
>>>
>>> This patch makes log file rotation the default. Default thresholds are
>>> 5 rotated files with a target size of 20MiB. Truncating behavior can
>>> be achieved by setting filecount to 0 (-Xlog::myfile.log::filecount=0).
>>>
>>> If a log file already exists during log file initialization it will be
>>> rotated. If any of the target file names (file.0 to file.4 in the
>>> default case) are available, that filename will be used for the
>>> existing log. If all names are taken the VM will attempt to overwrite
>>> the oldest file.
>>>
>>> This should prevent unlimited log file creations and avoid accidental
>>> loss of log files from previous runs. The default thresholds (5 files,
>>> 20MiB each) is just a suggestion. If you think it should be
>>> higher/lower let me know.
>>>
>>> Tested with included internal VM tests through RBT.
>>>
>>> Thanks,
>>> Marcus
>>>
>>> On 2016-03-01 15:05, Marcus Larsson wrote:
>>>> Hi,
>>>>
>>>> After some offline discussions I'm withdrawing this patch. I will
>>>> instead investigate if I can achieve similar behavior using log
>>>> rotation as the default.
>>>>
>>>> Thanks,
>>>> Marcus
>>>>
>>>> On 03/01/2016 12:11 PM, Marcus Larsson wrote:
>>>>> Hi again,
>>>>>
>>>>> Taking a different approach to this.
>>>>>
>>>>> New webrev:
>>>>> http://cr.openjdk.java.net/~mlarsson/8146879/webrev.01/
>>>>>
>>>>> Existing files will now by default be renamed/archived with a .X
>>>>> suffix where X is the lowest number such that the resulting file
>>>>> name is available (jvm.log becomes jvm.log.0). A mode option for
>>>>> controlling this behavior has been added as well. It can be set to
>>>>> archive, append, or truncate (i.e. -Xlog::jvm.log::mode=truncate).
>>>>>
>>>>> Tested with included jtreg test through JPRT.
>>>>>
>>>>> Thanks,
>>>>> Marcus
>>>>>
>>>>> On 01/14/2016 04:00 PM, Marcus Larsson wrote:
>>>>>> Hi,
>>>>>>
>>>>>> Please review the following patch to make sure UL truncates
>>>>>> existing log files before writing to them. Since files are opened
>>>>>> in append mode, truncation isn't done automatically, so instead the
>>>>>> patch adds an attempt to remove the log file before opening it.
>>>>>>
>>>>>> Webrev:
>>>>>> http://cr.openjdk.java.net/~mlarsson/8146879/webrev.00/
>>>>>>
>>>>>> Issue:
>>>>>> https://bugs.openjdk.java.net/browse/JDK-8146879
>>>>>>
>>>>>> Testing:
>>>>>> Included test through JPRT
>>>>>>
>>>>>> Thanks,
>>>>>> Marcus
>>>>>
>>>>
>>>
>>