Re: archive falling behind

The shell script call used in the archive_command is a bad idea.

Each time a new segment is archived a new shell is started and this add a
be massive overload, then and you have an extra overload for the ssh
transfer.....

I suggest you to stick with the simple cp command with the test option from
the manual then transfer the archived segments in a second time using a
more reliable system like rsync.

Cheers
Federico

On 26 April 2013 14:06, German Becker <german(dot)becker(at)gmail(dot)com> wrote:

> Here is the archive part of the config:
>
> archive_mode = on # allows archiving to be done
> # (change requires restart)
> archive_command = '/var/lib/postgresql/scripts/archive_copy.sh %p %f'
> # command to use to archive a logfile segment
> #archive_timeout = 0 # force a logfile segment switch after this
> # number of seconds; 0 disables
>
>
> The archive coommand makes a local copy and then it copies to the backup
> server via ssh. Both copies are md5-checked and retried up to 3 times in
> case of failure.
>
> I have seen under heavy load that some WALs are skipped, some have less
> size, some are corrupted (i,e, the loop fails 3 times).
> I'm not sure about the return value (checking it). What is the expected
> behaviour of the archiver? Will it retry de archive if archive command
> returns differnt than 0? Will it retain the WAL segment until it is
> succesfuly archived?
>
>
> On Fri, Apr 26, 2013 at 9:53 AM, Albe Laurenz <laurenz(dot)albe(at)wien(dot)gv(dot)at>wrote:
>
>> German Becker wrote:
>> > From my experience, postgres will delete WAL (after checkpoint)
>> regardless if they have been archived.
>> > Are you saying this is abnormal?
>>
>> That would be quite abnormal.
>> Could it be that your archive_command has exit status 0
>> even if something goes wrong?
>>
>> What are the archive settings?
>>
>> Yours,
>> Laurenz Albe
>>
>
>

--
Federico Campoli
DE MATERIALIZING, UK, Planet Earth, The Milky Way Galaxy
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