postgres$ ps -o pid,command --ppid `head -n 1 $PGDATA/postmaster.pid`
PID COMMAND 10810 postgres: 9.6/main: checkpointer process 10811 postgres: 9.6/main: writer process 10812 postgres: 9.6/main: wal writer process 10813 postgres: 9.6/main: autovacuum launcher process 10814 postgres: 9.6/main: stats collector process 30953 postgres: 9.6/main: autovacuum worker process plpgsql_exceptions
К процессам, обслуживающим буферный кэш и журнал, можно отнести:
postgres$ rm /var/log/postgresql/postgresql-9.6-main.log
student$ sudo pg_ctlcluster 9.6 main restart
Журнал сообщений сервера:
postgres$ cat /var/log/postgresql/postgresql-9.6-main.log
2017-08-25 22:15:54 MSK [2349-1] LOG: database system was shut down at 2017-08-25 22:15:52 MSK 2017-08-25 22:15:54 MSK [2349-2] LOG: MultiXact member wraparound protections are now enabled 2017-08-25 22:15:54 MSK [2348-1] LOG: database system is ready to accept connections 2017-08-25 22:15:54 MSK [2353-1] LOG: autovacuum launcher started 2017-08-25 22:15:54 MSK [2357-1] [unknown]@[unknown] LOG: incomplete startup packet
postgres$ rm /var/log/postgresql/postgresql-9.6-main.log
student$ sudo pg_ctlcluster 9.6 main stop -m immediate --skip-systemctl-redirect
student$ sudo pg_ctlcluster 9.6 main restart
Журнал сообщений сервера:
postgres$ cat /var/log/postgresql/postgresql-9.6-main.log
2017-08-25 22:15:56 MSK [2429-1] LOG: database system was interrupted; last known up at 2017-08-25 22:15:54 MSK 2017-08-25 22:15:56 MSK [2430-1] [unknown]@[unknown] LOG: incomplete startup packet 2017-08-25 22:15:57 MSK [2429-2] LOG: database system was not properly shut down; automatic recovery in progress 2017-08-25 22:15:57 MSK [2429-3] LOG: invalid record length at F/60A7A35C: wanted 24, got 0 2017-08-25 22:15:57 MSK [2429-4] LOG: redo is not required 2017-08-25 22:15:57 MSK [2433-1] postgres@postgres FATAL: the database system is starting up 2017-08-25 22:15:57 MSK [2429-5] LOG: MultiXact member wraparound protections are now enabled 2017-08-25 22:15:57 MSK [2428-1] LOG: database system is ready to accept connections 2017-08-25 22:15:57 MSK [2437-1] LOG: autovacuum launcher started
Перед тем, как начать принимать соединения, СУБД выполнила восстановление (automatic recovery in progress).