[Bucardo-general] Swap replication latency

[Itamar Reis Peixoto]

On Sun, May 1, 2011 at 7:30 AM, Alex Balashov <abalashov at evaristesys.com> wrote:
> Greetings,
>
> I apologise if this is a poorly researched question;  I looked through
> the list archived extensively and wasn't able to find anything that
> addressed my issue specifically.
>
> I've got a simple swap replication setup between two servers,
> consisting of a single sync of a single herd of a single database
> consisting of about 50 tables and about as many sequences.  Right now,
> it's kind of an active-passive setup, it's just that the slave needs
> to be writable in principle.
>
> Compared to the setups that I'm sure some users of Bucardo are
> running, I wouldn't say it's under a demanding load--maybe 5-6 writes
> transactions/sec at most?  Yet, I am seeing a lag of about 15-20
> minutes until changes on the primary server show up on the secondary.
>
> According to 'bucardo_ctl status <sync name>', I'm getting a "Last
> good" run time between 10 and 12 minutes, and typically involving
> ~250/2349/10 Ins/Upd/Del ops.  Ping is on.  Obviously, my logs are
> full of kicks and this message:
>
>   May  1 06:26:59 db Bucardo[28374]: CTL Could not add to q
>   sync=xxxxxxx_sync,source=xxxxxxx,target=xxxxxxxx_remote,count=1.
>   Sending manual notification
>
> Is this normal (not the message, the 15-20 minute lag)?  Is there
> anything I can do to speed it up and make the replication process a
> little more timely, if not necessarily real-time?  I have tinkered
> with a few of the options in the config table (i.e. 'bucardo_ctl show
> all'), but without much luck.  They aren't documented anywhere that I
> can find, so I'm reluctant to mess with them too much.
>
> I'm guessing that if there is a solution, it probably involves
> squeezing more out of each sync through increased statement
> length/value tuples, or by somehow further parallelising the sync
> process when it runs.
>
> Any light that can be shed would be deeply appreciated!
>
> Thanks,
>
> -- Alex
>
> --
> Alex Balashov - Principal
> Evariste Systems LLC
> 260 Peachtree Street NW
> Suite 2200
> Atlanta, GA 30303
> Tel: +1-678-954-0670
> Fax: +1-404-961-1892
> Web: http://www.evaristesys.com/


have you setup cron job ?

http://bucardo.org/wiki/Bucardo/Cron

-- 
------------

Itamar Reis Peixoto
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