Yes. It is the "writer process". It is still called as background writer process. It displays as "writer process" since PostgreSQL-8.0.
Venkata Balaji N
Sr. Database Administrator
Fujitsu Australia
On Tue, Mar 11, 2014 at 10:32 AM, Matthew Chambers <mchambers@xxxxxxxxxxxx> wrote:
This is postgres 9.3.2.
This is what the log shows.
Mar 11 08:16:29 jupiter521 postgres[2026]: [8-1] 2014-03-11 08:16:29 NZDTLOG: received SIGHUP, reloading configuration files
Mar 11 08:16:29 jupiter521 postgres[2026]: [9-1] 2014-03-11 08:16:29 NZDTLOG: parameter "bgwriter_lru_maxpages" changed to "200"
Here are the processes I have running besides the connections.
postgres 2028 0.0 8.3 17245532 8279356 ? Ss Mar09 2:42 postgres: checkpointer process
postgres 2029 0.0 0.1 17245272 107900 ? Ss Mar09 0:08 postgres: writer process
postgres 2030 0.2 0.0 17245272 34248 ? Ss Mar09 6:44 postgres: wal writer process
postgres 2031 0.0 0.0 17246164 2596 ? Ss Mar09 0:09 postgres: autovacuum launcher process
postgres 2032 0.0 0.0 18152 1244 ? Ss Mar09 0:06 postgres: archiver process last was 0000000100000202000000F8
postgres 2033 0.0 0.0 18568 1636 ? Ss Mar09 1:47 postgres: stats collector process
postgres 3914 0.4 0.0 17246520 2844 ? Ss Mar09 14:04 postgres: wal sender process postgres 192.168.122.54(48686) streaming 202/F996C000
Is it the "writer process"? I was sure it was called the background writer before.
-Matt
On 11/03/14 12:03, Venkata Balaji Nagothi wrote:
On Tue, Mar 11, 2014 at 8:30 AM, Matthew Chambers <mchambers@xxxxxxxxxxxx> wrote:
Hi, just wondering if this is normal, DB is operating just fine.
I upped bgwriter_lru_maxpages to 200 and issued a reload. Normally, I'd see the bgwriter constantly churning as one of my main I/O using processes, but now I have:
postgres: wal writer process
postgres: checkpointer process
The wal writer seems to have taken over. Does this make sense?
What WAL writer does is completely different from the way bgwriter functions. These two critical background processes of PostgreSQL performing independent I/O operations independently.One cannot take over another.
which version of Postgres is this ?
Do you see anything in the Postgres logs ? Do you see any message which indicates that reloading of the new configuration in postgresql.conf file was successful ?
Venkata Balaji N
Sr. Database AdministratorFujitsu Australia
