Update example of process titles shown by "ps".

This example was quite old: it lacked the WAL writer and autovac launcher
as well as the more recently added checkpointer.  Linux "ps" seems to show
slightly different stuff now too.
This commit is contained in:
Tom Lane 2012-05-11 18:33:39 -04:00
parent d0c231d132
commit f35ebd2aa1
1 changed files with 19 additions and 11 deletions

View File

@ -48,23 +48,27 @@
<screen>
$ ps auxww | grep ^postgres
postgres 960 0.0 1.1 6104 1480 pts/1 SN 13:17 0:00 postgres -i
postgres 963 0.0 1.1 7084 1472 pts/1 SN 13:17 0:00 postgres: writer process
postgres 965 0.0 1.1 6152 1512 pts/1 SN 13:17 0:00 postgres: stats collector process
postgres 998 0.0 2.3 6532 2992 pts/1 SN 13:18 0:00 postgres: tgl runbug 127.0.0.1 idle
postgres 1003 0.0 2.4 6532 3128 pts/1 SN 13:19 0:00 postgres: tgl regression [local] SELECT waiting
postgres 1016 0.1 2.4 6532 3080 pts/1 SN 13:19 0:00 postgres: tgl regression [local] idle in transaction
postgres 15551 0.0 0.1 57536 7132 pts/0 S 18:02 0:00 postgres -i
postgres 15554 0.0 0.0 57536 1184 ? Ss 18:02 0:00 postgres: writer process
postgres 15555 0.0 0.0 57536 916 ? Ss 18:02 0:00 postgres: checkpointer process
postgres 15556 0.0 0.0 57536 916 ? Ss 18:02 0:00 postgres: wal writer process
postgres 15557 0.0 0.0 58504 2244 ? Ss 18:02 0:00 postgres: autovacuum launcher process
postgres 15558 0.0 0.0 17512 1068 ? Ss 18:02 0:00 postgres: stats collector process
postgres 15582 0.0 0.0 58772 3080 ? Ss 18:04 0:00 postgres: joe runbug 127.0.0.1 idle
postgres 15606 0.0 0.0 58772 3052 ? Ss 18:07 0:00 postgres: tgl regression [local] SELECT waiting
postgres 15610 0.0 0.0 58772 3056 ? Ss 18:07 0:00 postgres: tgl regression [local] idle in transaction
</screen>
(The appropriate invocation of <command>ps</> varies across different
platforms, as do the details of what is shown. This example is from a
recent Linux system.) The first process listed here is the
master server process. The command arguments
shown for it are the same ones used when it was launched. The next two
shown for it are the same ones used when it was launched. The next five
processes are background worker processes automatically launched by the
master process. (The <quote>stats collector</> process will not be present
if you have set
the system not to start the statistics collector.) Each of the remaining
if you have set the system not to start the statistics collector; likewise
the <quote>autovacuum launcher</> process can be disabled.)
Each of the remaining
processes is a server process handling one client connection. Each such
process sets its command line display in the form
@ -79,8 +83,12 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
or a command type name such as <literal>SELECT</>. Also,
<literal>waiting</> is appended if the server process is presently waiting
on a lock held by another session. In the above example we can infer
that process 1003 is waiting for process 1016 to complete its transaction and
thereby release some lock.
that process 15606 is waiting for process 15610 to complete its transaction
and thereby release some lock. (Process 15610 must be the blocker, because
there is no other active session. In more complicated cases it would be
necessary to look into the
<link linkend="view-pg-locks"><structname>pg_locks</structname></link>
system view to determine who is blocking whom.)
</para>
<para>