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matanster
Asked: 2014-11-10 00:24:26 +0800 CST

how to nicely stop all postgres processes

  • 772

How do you nicely stop all postgres processes with pg_ctl (or otherwise), when you don't recall what the database directory is, nor have the PGDATA environment variable defined?

postgresql

4 Answers

  1. Best Answer

    It's safe to:

    sudo pkill -u postgres

    That kills all processes running as user postgres. Or:

    pkill postgres

    That kills all processes named 'postgres'.

    Do not use kill -9 (kill -KILL). Just kill (without options) does a SIGTERM, which is what you want.

    Alternatively, you can check the pgdata location if you can connect to PostgreSQL. For example:

    sudo -u postgres psql -c "SHOW data_directory";

    ...or by checking its environment variables in /proc/[postmaster pid]/environ, where you identify the postmaster with ps -fHC postgres. Look for the one that's the parent of the other postgres processes. For example:

    postgres   794     1  0 Nov06 ?        00:00:03 /usr/pgsql-9.3/bin/postgres -D /var/lib/pgsql/9.3/data -p 5432
postgres   857   794  0 Nov06 ?        00:00:00   postgres: logger process   
postgres   871   794  0 Nov06 ?        00:00:00   postgres: checkpointer process   
postgres   872   794  0 Nov06 ?        00:00:00   postgres: writer process   
postgres   873   794  0 Nov06 ?        00:00:00   postgres: wal writer process   
postgres   874   794  0 Nov06 ?        00:00:03   postgres: autovacuum launcher process   
postgres   875   794  0 Nov06 ?        00:00:07   postgres: stats collector process

    Its datadir will generally be shown on its command line.

    • 70

  2. It makes me nervous seeing kill and postgres in the same command. To answer the question using only pg_ctl, that would be:

    pg_ctl -D $(psql -Xtc 'show data_directory') stop

    The -X argument says to ignore the .psqlrc file. This is useful if you have psql configured to emit the time taken by a query (via the \timing command).

    The -t argument says to remove the column name at the top of the output and the total number of rows produced.

    The -c argument contains the SQL code to be executed.

    Running a bare psql -c 'show data_directory' will probably produce the following output:

          data_directory
--------------------------
 /path/to/postgresql/data
(1 row)

    Hence, backticking this through $( ... ) will deliver /path/to/postgresql/data to the -D argument of pg_ctl, which will then stop the database in an orderly manner.

    • 6

  3. This work for me ref. https://stackoverflow.com/a/5408501/248616

    SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = 'YOUR_NAME';
    • 1

  4. You can simply run the command

    systemctl stop postgresql

    When you wish to restart it run

    systemctl start postgresql
    • It is likely these commands will require you to append sudo
    • 0