Why i see several postgres server processes sometimes ?
Hi,
I wander why i see several postgres server processes with different PIDs
I don't mean those normal query processes. I see several of these:
/usr/lib/postgresql/8.4/bin/postgres -D /database/postgresql/8.4/main -c
config_file=/etc/postgresql/8.4/main/postgresql.conf
With different pids. Is this normal ?
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
COMMAND
27662 postgres 20 0 1623m 14m 10m R 5 0.3 0:00.14 postgres: wmg
wmg 172.18.9.21(43725)
idle
15489 postgres 20 0 1610m 33m 33m S 3 0.7 76:51.46
/usr/lib/postgresql/8.4/bin/postgres -D /database/postgresql/8.4/main -c
config_file=/etc/postgresql/8.4/main/postgresql.conf
27714 postgres 20 0 1613m 7720 5228 S 1 0.2 0:00.03 postgres: wmg
wmg 172.18.9.12(42434)
idle
27730 postgres 20 0 1611m 2336 1228 R 1 0.0 0:00.02
/usr/lib/postgresql/8.4/bin/postgres -D /database/postgresql/8.4/main -c
config_file=/etc/postgresql/8.4/main/postgresql.conf
27731 postgres 20 0 1610m 1572 1044 R 1 0.0 0:00.02
/usr/lib/postgresql/8.4/bin/postgres -D /database/postgresql/8.4/main -c
config_file=/etc/postgresql/8.4/main/postgresql.conf
15494 postgres 20 0 1611m 1.5g 1.5g S 0 30.6 6:10.54 postgres:
writer
process
27711 postgres 20 0 1613m 7752 5248 S 0 0.2 0:00.01 postgres: wmg
wmg 172.18.9.13(53169)
idle
27729 postgres 20 0 1610m 1572 1044 R 0 0.0 0:00.01
/usr/lib/postgresql/8.4/bin/postgres -D /database/postgresql/8.4/main -c
config_file=/etc/postgresql/8.4/main/postgresql.conf
15495 postgres 20 0 1611m 1020 652 S 0 0.0 0:23.09 postgres: wal
writer
process
15496 postgres 20 0 1612m 1648 564 S 0 0.0 0:24.77 postgres:
autovacuum launcher
process
15497 postgres 20 0 73524 1308 296 S 0 0.0 18:29.63 postgres: stats
collector
process
17480 postgres 20 0 37052 940 936 S 0 0.0 0:00.01 su
postgres
17481 postgres 20 0 19384 1236 1232 S 0 0.0 0:00.01
bash
17510 postgres 20 0 67696 2400 1992 S 0 0.0 0:00.12
/usr/lib/postgresql/8.4/bin/psql
wmg
17537 postgres 20 0 1617m 26m 21m S 0 0.5 0:00.12 postgres:
postgres wmg [local]
idle
27722 postgres 20 0 1614m 10m 7372 R 0 0.2 0:00.00 postgres: wmg
wmg 172.18.9.13(53195)
idle
27724 postgres 20 0 1613m 7700 5208 R 0 0.2 0:00.00 postgres: wmg
wmg 172.18.9.12(42452)
PARSE
27727 postgres 20 0 1613m 4324 2336 R 0 0.1 0:00.00 postgres: wmg
wmg 172.18.9.13(53204)
startup
27732 postgres 20 0 1610m 424 0 R 0 0.0 0:00.00
/usr/lib/postgresql/8.4/bin/postgres -D /database/postgresql/8.4/main -c
config_file=/etc/postgresql/8.4/main/postgresql.conf
27733 postgres 20 0 1610m 424 0 R 0 0.0 0:00.00
/usr/lib/postgresql/8.4/bin/postgres -D /database/postgresql/8.4/main -c
config_file=/etc/postgresql/8.4/main/postgresql.conf
On 6 October 2010 15:44, Georgi Ivanov <georgi.r.ivanov@gmail.com> wrote:
Hi,
I wander why i see several postgres server processes with different PIDs
I don't mean those normal query processes. I see several of these:
/usr/lib/postgresql/8.4/bin/postgres -D /database/postgresql/8.4/main -c
config_file=/etc/postgresql/8.4/main/postgresql.conf
With different pids. Is this normal ?
This is normal. Postgres is said to have a multi-process architecture
(which is often contrasted with a multi threaded architecture). The
number of processes isn't very predictable.
--
Regards,
Peter Geoghegan
Peter,
This is normal. Postgres is said to have a multi-process architecture
(which is often contrasted with a multi threaded architecture). The
number of processes isn't very predictable.you are right, it is normal.
But the number of processes is quite predictable:
on default PostgreSQL starts up with 5 processes:
one background-writer
one postmaster who masters the startup of additional progresses
one autovacuum-daemon
two processes which I have not leveled up enough to know what they are doing
And then there is one additional process for every client connection.
Harald
--
GHUM GmbH
Harald Armin Massa
Spielberger Straße 49
70435 Stuttgart
0173/9409607
Amtsgericht Stuttgart, HRB 734971
-
persuadere.
et programmare
On 06/10/2010 18:53, Massa, Harald Armin wrote:
Peter,
This is normal. Postgres is said to have a multi-process architecture
(which is often contrasted with a multi threaded architecture). The
number of processes isn't very predictable.you are right, it is normal.
But the number of processes is quite predictable:
on default PostgreSQL starts up with 5 processes:
one background-writer
one postmaster who masters the startup of additional progresses
one autovacuum-daemon
two processes which I have not leveled up enough to know what they are doing
And then there is one additional process for every client connection.
So that's where the extra processes are coming from - something is
holding connections open.
Ray.
--
Raymond O'Donnell :: Galway :: Ireland
rod@iol.ie