On Thu, 18 Jun 2015 15:17 Xavier 12 <maniatux@xxxxxxxxx>
wrote:
On 18/06/2015 04:00, Sameer Kumar wrote:
On Wed, 17 Jun 2015 15:24 Xavier 12 <maniatux@xxxxxxxxx>
wrote:
On 17/06/2015 03:17, Sameer Kumar wrote:
On Tue, 16 Jun 2015 16:55 Xavier 12 <maniatux@xxxxxxxxx>
wrote:
Hi everyone,
Questions about pg_xlogs again...
I have two Postgresql 9.1 servers in a master/slave
stream replication
(hot_standby).
Psql01 (master) is backuped with Barman and
pg_xlogs is correctly
purged (archive_command is used).
Hower, Psql02 (slave) has a huge pg_xlog
(951 files, 15G for 7 days
only, it keeps growing up until disk space is full). I
have found
documentation and tutorials, mailing list, but I don't
know what is
suitable for a Slave. Leads I've found :
- checkpoints
- archive_command
- archive_cleanup
Master postgresq.conf :
[...]
wal_level = 'hot_standby'
archive_mode = on
archive_command = 'rsync -az
/var/lib/postgresql/9.1/main/pg_xlog/%f
barman@xxxxxxx:/data/pgbarman/psql01/incoming/%f'
max_wal_senders = 5
wal_keep_segments = 64
What's this parameter's value on Slave?
Hm... You have a point.
That autovacuum parameter seems to be useless on a slave.
I'll try to remove it and check pg_xlog.
That was not my point. I was actually asking about
wal_keep_segment. Nevermind I found that I had misses the
info (found it below. Please see my response).
Besides I try to keep my master and standby config as same
as possible(so my advise ia to not switchoff autovacuum).
The parameters which are imeffective on slave anyways won't
have an effect. Same goes for parameters on master.
This helps me when I swap roles or do a failover. I have
less parameters to be worried about.
Okay
Can you check the pg_log for log files. They may
have se info? I am sorry if you have already provided that
info (after I finish I will try to look at your previous
emails on this thread)
Nothing...
/var/log/postgresql/postgresql-2015-06-17_111131.log is empty
(except old messages at the begining related to a
configuration issue - which is now solved - after rebuilding
the cluster yesterday).
/var/log/syslog has nothing but these :
Jun 18 09:10:11 Bdd02 postgres[28400]: [2-1]
2015-06-18 09:10:11 CEST LOG: paquet de d?marrage incomplet
Jun 18 09:10:41 Bdd02 postgres[28523]: [2-1] 2015-06-18
09:10:41 CEST LOG: paquet de d?marrage incomplet
Jun 18 09:11:11 Bdd02 postgres[28557]: [2-1] 2015-06-18
09:11:11 CEST LOG: paquet de d?marrage incomplet
Jun 18 09:11:41 Bdd02 postgres[28652]: [2-1] 2015-06-18
09:11:41 CEST LOG: paquet de d?marrage incomplet
Jun 18 09:12:11 Bdd02 postgres[28752]: [2-1] 2015-06-18
09:12:11 CEST LOG: paquet de d?marrage incomplet
Jun 18 09:12:41 Bdd02 postgres[28862]: [2-1] 2015-06-18
09:12:41 CEST LOG: paquet de d?marrage incomplet
Jun 18 09:13:11 Bdd02 postgres[28891]: [2-1] 2015-06-18
09:13:11 CEST LOG: paquet de d?marrage incomplet
Jun 18 09:13:40 Bdd02 postgres[28987]: [2-1] 2015-06-18
09:13:40 CEST LOG: paquet de d?marrage incomplet
These messages are related to Zabbix (psql port
check).
You sure these are the only messages you have in the log files?
Also can you share the vacuum cost parameters in
your environm
en
t?
I don't understand that part... is this in
postgresql.conf ?
There are vacuum cost parameters in postgresql.conf
http://www.postgresql.org/docs/9.4/static/runtime-config-resource.html#RUNTIME-CONFIG-RESOURCE-VACUUM-COST
autovacuum = on
Slave postgresql.conf :
[...]
wal_level = minimal
wal_keep_segments = 32
Sorry I missed this somehow earlier. Any reason why you
think you need to retain 32 wal files on slave?
No but I get the feeling that the parameter is
ignored by my slave... should I try another value ?
AFAIK you don't nees this parameter to set to > 0 unless you
have cascaded replica pull wal from stand by or you have backup
jobs running to backup from standby. Set it to 0 on the standby
and check.
hot_standby = on
Slave recovery.conf :
standby_mode = 'on'
primary_conninfo = 'host=10.0.0.1 port=5400
user=postgres'
trigger_file = '/var/lib/postgresql/9.1/triggersql'
restore_command='cp
/var/lib/postgresql/9.1/wal_archive/%f "%p"'
archive_cleanup_command =
'/usr/lib/postgresql/9.1/bin/pg_archivecleanup
/var/lib/postgresql/9.1/wal_archive/ %r'
Also consider setting hot_standby_feesback to on.
I will check that parameter in the documentation,
Thanks
How can I reduce the number of WAL files on
the hot_stanby slave ?
