Thread: pg_xlog piling

Hi,

I have a standby that is in replication only mode but the pg_xlog 
directory is currently at 577GB utilized and is growing daily and I 
can't figure out why. This was a problem before when we were on 
postgresl 9.2 but changed some postgresql.conf parameters and then 
rebuilt it but still running into the same problem.


Thanks in advance,

Chris


Here is some more info about the standby.


# WRITE AHEAD LOG
#------------------------------------------------------------------------------

# - Settings -

wal_level = hot_standby            # minimal, archive, or hot_standby

                     # (change requires restart)
#fsync = off                # turns forced synchronization on or off
#synchronous_commit = off        # synchronization level;
                     # off, local, remote_write, or on
#wal_sync_method = fsync        # the default is the first option
                     # supported by the operating system:
                     #   open_datasync
                     #   fdatasync (default on Linux)
                     #   fsync
                     #   fsync_writethrough
                     #   open_sync
#full_page_writes = on            # recover from partial page writes
#wal_buffers = -1            # min 32kB, -1 sets based on shared_buffers
                     # (change requires restart)
#wal_writer_delay = 200ms        # 1-10000 milliseconds

#commit_delay = 0            # range 0-100000, in microseconds
#commit_siblings = 5            # range 1-1000

# - Checkpoints -

checkpoint_segments = 128        # in logfile segments, min 1, 16MB each
checkpoint_timeout = 30min
#checkpoint_timeout = 5min        # range 30s-1h
#checkpoint_completion_target = 0.5    # checkpoint target duration, 0.0 
- 1.0
checkpoint_warning = 30min
#checkpoint_warning = 30s        # 0 disables


# REPLICATION
#------------------------------------------------------------------------------

# - Sending Server(s) -

# Set these on the master and on any standby that will send replication 
data.

max_wal_senders = 3        # max number of walsender processes
                 # (change requires restart)
wal_keep_segments = 256        # in logfile segments, 16MB each; 0 disables
#wal_keep_segments = 500        # in logfile segments, 16MB each; 0 disables
#replication_timeout = 60s    # in milliseconds; 0 disables

# - Master Server -

# These settings are ignored on a standby server.

#synchronous_standby_names = ''    # standby servers that provide sync rep
                 # comma-separated list of application_name
                 # from standby(s); '*' = all
#vacuum_defer_cleanup_age = 0    # number of xacts by which cleanup is 
delayed

# - Standby Servers -

# These settings are ignored on a master server.

hot_standby = on            # "on" allows queries during recovery
                     # (change requires restart)
#max_standby_archive_delay = 30s    # max delay before canceling queries
                     # when reading WAL from archive;
                     # -1 allows indefinite delay
#max_standby_streaming_delay = 30s    # max delay before canceling queries
                     # when reading streaming WAL;
                     # -1 allows indefinite delay
#wal_receiver_status_interval = 10s    # send replies at least this often
                     # 0 disables
#hot_standby_feedback = off        # send info from standby to prevent
                     # query conflicts


postgres=# show checkpoint_segments;
  checkpoint_segments
---------------------
  128
(1 row)

postgres=# show wal_keep_segments;
  wal_keep_segments
-------------------
  256
(1 row)

On Tuesday, January 30, 2018, chris <chrisk@pgsqlrocket.com> wrote:

This was a problem before when we were on postgresl 9.2 

still on version 9.2

On Tuesday, January 30, 2018, chris <chrisk@pgsqlrocket.com> wrote:

This was a problem before when we were on postgresl 9.2 

What version are you on now?

David J. 

postgres=# select * from pg_stat_replication;pid  | usesysid | usename  | application_name |  client_addr   |
client_hostname | client_port |         backend_start         |   state   |
sent_location | write_location | flush_location | replay_locatio
n | sync_priority | sync_state 
------+----------+----------+------------------+----------------+-----------------+-------------+-------------------------------+-----------+---------------+----------------+----------------+---------------
--+---------------+------------5303 |       10 | postgres | walreceiver      | 198.161.184.74 |               |       57049 | 2017-12-14 11:13:16.339948-07 | streaming | 2FD3/41A38140 |
2FD3/41A38140  | 2FD3/41A38140  | 2F47/7015D490  |             0 | async
(1 row)

postgres=# 

# - Archiving -

archive_mode = on        # allows archiving to be done

archive_command = 'cp %p /ComplianceDB/pitr/walstage/%f; mv /ComplianceDB/pitr/walstage/%f /ComplianceDB/pitr/wal/%f'                # (change requires restart)
#archive_command = ''        # command to use to archive a logfile segment
                # placeholders: %p = path of file to archive
                #               %f = file name only
                # e.g. 'test ! -f /mnt/server/archivedir/%f && cp %p /mnt/server/archivedir/%f'
#archive_timeout = 0        # force a logfile segment switch after this
                # number of seconds; 0 disables
Thanks

what is your archive command and is your replica up to date?  Any messages in the pg_log that would indicate the replica is not receiving update ?

On Tue, Jan 30, 2018 at 11:09 AM, David G. Johnston <david.g.johnston@gmail.com> wrote:

On Tuesday, January 30, 2018, chris <chrisk@pgsqlrocket.com> wrote:

This was a problem before when we were on postgresl 9.2 

What version are you on now?

David J. 

--

Thanks,

Jorge Torralba
----------------------------

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chris wrote:
> I have a standby that is in replication only mode but the pg_xlog 
> directory is currently at 577GB utilized and is growing daily and I 
> can't figure out why. This was a problem before when we were on 
> postgresl 9.2 but changed some postgresql.conf parameters and then 
> rebuilt it but still running into the same problem.

What do you get on the primary for

   SELECT state, sent_location, write_location, flush_location, replay_location
   FRPM pg_stat_replication;

Yours,
Laurenz Albe