Thread: Should data directories match between master and hot standby?

Should data directories match between master and hot standby?

From
Brian Fehrle
Date:
Hi all,

I have a hot standby (via streaming replication) set up on a postgresql
9.0.4 system.

(I'm looking at base to eliminate differences in xlog and pg_log, etc)
The size of my base directory on the master is 775G, the size of the
base directory on the hot standby is 804G.

Is this normal? Collecting the info from the master and the slave using
the following shows I'm in sync:

[on the master]  select pg_current_xlog_location()   ->
pg_xlogfile_name_offset -> (0000000100007AB0000000E7,7282688)
[on the slave]  select pg_last_xlog_receive_location() ->
pg_xlogfile_name_offset -> (0000000100007AB0000000E7,7282688)
[on the slave]  select pg_last_xlog_replay_location() ->
pg_xlogfile_name_offset -> (0000000100007AB0000000E7,7281296)

So I'm in sync, not like the slave is waiting on a huge delete or anything.

Any thoughts or ideas what this could be?

Thanks in advance,

- Brian F


Re: Should data directories match between master and hot standby?

From
Brian Fehrle
Date:
Hi all,

Looks like I found the reason. There is a huge query on the slave that
has been running for 5 hours. It's doing major sorting and has claimed
29 gigs in the base/pgsql_tmp/ directory, which is the excact
discrepancy between the master and the slave.

So makes sense, I'm good,

- Brian F

On 10/03/2012 02:01 PM, Brian Fehrle wrote:
> Hi all,
>
> I have a hot standby (via streaming replication) set up on a
> postgresql 9.0.4 system.
>
> (I'm looking at base to eliminate differences in xlog and pg_log, etc)
> The size of my base directory on the master is 775G, the size of the
> base directory on the hot standby is 804G.
>
> Is this normal? Collecting the info from the master and the slave
> using the following shows I'm in sync:
>
> [on the master]  select pg_current_xlog_location()   ->
> pg_xlogfile_name_offset -> (0000000100007AB0000000E7,7282688)
> [on the slave]  select pg_last_xlog_receive_location() ->
> pg_xlogfile_name_offset -> (0000000100007AB0000000E7,7282688)
> [on the slave]  select pg_last_xlog_replay_location() ->
> pg_xlogfile_name_offset -> (0000000100007AB0000000E7,7281296)
>
> So I'm in sync, not like the slave is waiting on a huge delete or
> anything.
>
> Any thoughts or ideas what this could be?
>
> Thanks in advance,
>
> - Brian F
>
>