Re: Streaming Replication Randomly Locking Up

The only thing I see that is a possibility for the issue is in the slave
log:

LOG: unexpected EOF on client connection
LOG: could not receive data from client: Connection reset by peer

I don't know if that's related or not as it could just be somebody running
a query. The log file does seem to be riddled with these but the
replication failures don't happen constantly.

As far as I know I'm not swallowing any errors. The logging is all set as
the default:

log_destination = 'stderr'
logging_collector = on
#client_min_messages = notice
#log_min_messages = warning
#log_min_error_statement = error
#log_min_duration_statement = -1
#log_checkpoints = off
#log_connections = off
#log_disconnections = off
#log_error_verbosity = default

I'm going to have a look at the NICs to make sure there's no issue there.

Thanks again for your help!

On Thu, Aug 15, 2013 at 11:51 AM, Lonni J Friedman <netllama(at)gmail(dot)com>wrote:

> Are you certain that there are no relevant errors in the database logs
> (on both master & slave)? Also, are you sure that you didn't
> misconfigure logging such that errors wouldn't appear?
>
> On Thu, Aug 15, 2013 at 11:45 AM, Andrew Berman <rexxe98(at)gmail(dot)com> wrote:
> > Hi Lonni,
> >
> > Yes, I am using PG 9.1.9.
> > Yes, 1 slave syncing from the master
> > CentOS 6.4
> > I don't see any network or hardware issues (e.g. NIC) but will look more
> > into this. They are communicating on a private network and switch.
> >
> > I forgot to mention that after I restart the slave, everything syncs
> right
> > back up and all if working again so if it is a network issue, the
> > replication is just stopping after some hiccup instead of retrying and
> > resuming when things are back up.
> >
> > Thanks!
> >
> >
> >
> > On Thu, Aug 15, 2013 at 11:32 AM, Lonni J Friedman <netllama(at)gmail(dot)com>
> > wrote:
> >>
> >> I've never seen this happen. Looks like you might be using 9.1? Are
> >> you up to date on all the 9.1.x releases?
> >>
> >> Do you have just 1 slave syncing from the master?
> >> Which OS are you using?
> >> Did you verify that there aren't any network problems between the
> >> slave & master?
> >> Or hardware problems (like the NIC dying, or dropping packets)?
> >>
> >>
> >> On Thu, Aug 15, 2013 at 11:07 AM, Andrew Berman <rexxe98(at)gmail(dot)com>
> wrote:
> >> > Hello,
> >> >
> >> > I'm having an issue where streaming replication just randomly stops
> >> > working.
> >> > I haven't been able to find anything in the logs which point to an
> >> > issue,
> >> > but the Postgres process shows a "waiting" status on the slave:
> >> >
> >> > postgres 5639 0.1 24.3 3428264 2970236 ? Ss Aug14 1:54
> >> > postgres:
> >> > startup process recovering 000000010000053D0000003F waiting
> >> > postgres 5642 0.0 21.4 3428356 2613252 ? Ss Aug14 0:30
> >> > postgres:
> >> > writer process
> >> > postgres 5659 0.0 0.0 177524 788 ? Ss Aug14 0:03
> >> > postgres:
> >> > stats collector process
> >> > postgres 7159 1.2 0.1 3451360 18352 ? Ss Aug14 17:31
> >> > postgres:
> >> > wal receiver process streaming 549/216B3730
> >> >
> >> > The replication works great for days, but randomly seems to lock up
> and
> >> > replication halts. I verified that the two databases were out of sync
> >> > with
> >> > a query on both of them. Has anyone experienced this issue before?
> >> >
> >> > Here are some relevant config settings:
> >> >
> >> > Master:
> >> >
> >> > wal_level = hot_standby
> >> > checkpoint_segments = 32
> >> > checkpoint_completion_target = 0.9
> >> > archive_mode = on
> >> > archive_command = 'rsync -a %p foo(at)foo:/var/lib/pgsql/9.1/wals/%f
> >> > </dev/null'
> >> > max_wal_senders = 2
> >> > wal_keep_segments = 32
> >> >
> >> > Slave:
> >> >
> >> > wal_level = hot_standby
> >> > checkpoint_segments = 32
> >> > #checkpoint_completion_target = 0.5
> >> > hot_standby = on
> >> > max_standby_archive_delay = -1
> >> > max_standby_streaming_delay = -1
> >> > #wal_receiver_status_interval = 10s
> >> > #hot_standby_feedback = off
> >> >
> >> > Thank you for any help you can provide!
> >> >
> >> > Andrew
> >> >
>