[Pgpool-committers] pgpool - pgpool-II: Add "failover_command" and "failback_command"

[User Y-asaba]

Log Message:
-----------
Add "failover_command" and "failback_command" directives.
If failover or failback occur, pgpool execute setting command by system(3).
These directives evaluate special characters with the following rule.

  %d: node id
  %h: backend's hostname
  %p: backend's port number
  %D: backend's data directory

example)
pgpool.conf:
---
  failover_command = 'echo %h %p %D %d > /tmp/failover'
  failback_command = 'echo %h %p %D %d > /tmp/failback'

  backend_hostname1 = 'localhost'
  backend_port1 = 5433
  backend_weight1 = 1
  backend_data_directory1 = '/home/postgres/pgdata/data5433'
---

When node 1 is down, pgpool execute the following failover command.

  failover localhost 5433 /home/postgres/pgdata/data5433 1

/tmp/failover is created.

  % cat /tmp/failover
  failover localhost 5433 /home/postgres/pgdata/data5433 1

Modified Files:
--------------
    pgpool-II:
        pgpool.conf.sample (r1.6 -> r1.7)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/pgpool.conf.sample.diff?r1=1.6&r2=1.7)
        main.c (r1.15 -> r1.16)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/main.c.diff?r1=1.15&r2=1.16)
        pool.h (r1.14 -> r1.15)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/pool.h.diff?r1=1.14&r2=1.15)
        pool_config.c (r1.9 -> r1.10)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/pool_config.c.diff?r1=1.9&r2=1.10)
        pool_config.l (r1.7 -> r1.8)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/pool_config.l.diff?r1=1.7&r2=1.8)
        pool_process_query.c (r1.44 -> r1.45)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/pool_process_query.c.diff?r1=1.44&r2=1.45)
    pgpool-II/parser:
        gram.c (r1.3 -> r1.4)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/parser/gram.c.diff?r1=1.3&r2=1.4)
        gram.h (r1.3 -> r1.4)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/parser/gram.h.diff?r1=1.3&r2=1.4)
        gram.y (r1.1.1.1 -> r1.2)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/parser/gram.y.diff?r1=1.1.1.1&r2=1.2)
        pool_string.c (r1.2 -> r1.3)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/parser/pool_string.c.diff?r1=1.2&r2=1.3)
        pool_string.h (r1.2 -> r1.3)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgpool/pgpool-II/parser/pool_string.h.diff?r1=1.2&r2=1.3)