Syncing just WAL archive directory every minute should not be a problem at all (running rsync every minute for a data directory is not recommended).
As said earlier, we had configured warm standby for a db of size 2 TB and wal archive generation was in 100s.
We did not encounter any issues in running an rsync job with a frequency of even less than a minute. We made sure that
rsync job is running on standby server (we were pulling the wal archives to standby).
1. compress the wal archives
2. rsync on standby site
3. uncompress on standby site
Thanks
Venkat
On Sat, Sep 17, 2011 at 6:06 PM, MirrorX
<mirrorx@gmail.com> wrote:
just another update since the system is up and running and one more question
:p
the secondary server is able to restore the wal archives practically
immediately after they arrive. i have set a rsync cron job to send the new
wals every 5 minutes. the procedure to transfer the files and to restore
them takes about 30 seconds (the number of archives is about 20-30). i ve
tried to set it to 2 minutes, and then the procedure takes about 20 seconds
(both transfer and restoration) while i didnt notice any impact on the
primary server (the procedure is initiated on the secondary server). what is
your opinion about the time interval that the cron job should run? i ve
read many articles online indicating that rsync should not run every 1
minute, but in my case isn't it different since it just syncs two folder
containing only wals and not the whole disks? plus both folders on the
servers are in different partitions.
thx in advance for your insight
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