[Gluster-devel] Geo-replication fills up inode by saving processed changelog files

[Vijay Bellur]

On 12/15/2014 11:13 AM, Aravinda wrote:
> On 12/15/2014 10:39 AM, Vijay Bellur wrote:
>> On 12/11/2014 11:40 AM, Aravinda wrote:
>>> Hi,
>>>
>>>
>>> While geo-replication is running it keeps processed changelog files in
>>> $WORKING_DIR/.processed or $WORKING_DIR/.history/.processed. These
>>> changelog files are useful for debugging processed changelogs. But these
>>> changelogs eats up the space/available inodes. The changelog files saved
>>> in processed directory is duplicate of changelogs available in brick
>>> backend(Difference is in the format, changelogs in processed dir are
>>> parsed and human readable).
>>
>> Do we consume 2 inodes per changelog - one in $WORKING_DIR and another
>> in the brick? If yes, how do we avoid consuming inodes in the
>> filesystem that contains the brick?
> Changelog generated by changelog translator saved in brick. When a
> consumer is registers working dir through libgfchangelog api processes
> brick changelog and copies to working dir.
>>

How are the changelogs in the bricks cleaned up?


>>>
>>> How about keeping only the reference to changelog file after processed.
>>> For debugging their will be additional step to look for changelog from
>>> backend($BRICK/.glusterfs/changelogs) using this reference.
>>>
>>> After syncing data to slave(In geo-replication)
>>> echo $changelog_filename >> $WORKING_DIR/.processed_files
>>> rm $WORKING_DIR/.processing/$changelog_filename
>>>
>>> We need to modify `gf_changelog_done` and `gf_history_changelog_done`
>>> functions in
>>> libgfchangelog($GLUSTER_SRC/xlators/features/changelog/lib/src)
>>>
>>> Any thoughts?
>>
>> Archiving retired changelogs may be an option. What would be the
>> scenario when there are multiple changelog consumers (apart from
>> geo-replication)?
> Each consumer registers a working dir, so it will not affect other
> consumers if we archive. Only issue could be backend changelogs are not
> copied in sosreports,(may be difficult to debug without copy of
> changelog in working dir)

sosreport plugin does pick up everything in working directory. If the 
changelogs get archived in the working directory, this should not be a 
problem right?

-Vijay