pgpool is a connection pool server for PostgreSQL.
pgpool runs between PostgreSQL's client and server.
Any PostgreSQL client can connect to pgpool as if it's a real PostgreSQL server.
pgpool caches the connection to the PostgreSQL server to reduce the overhead
involved in establishing the connection to it. pgpool can also be
used with two PostgreSQL servers for fail over purposes. If the first
server goes down, pgpool will automatically switch to the secondary server.
When started without arguments, pgpool starts as a daemon in the background.
When started with the argument stop, pgpool is shut down.
With the argument switch, pgpool will switch between master
and secondary servers. If only one server is configured, this will only
restart the child processes.
pgpool is typically started and stopped via system initialization scripts.
Print lots of debug messages.
Sets the path to the configuration file (default: /etc/pgpool.conf).
Print a help message and exit.
Shutdown mode: smart, fast, or immediate.
Do not start as daemon. Error messages go to stdout or stderr. Thus
you could play with utilities such as logger(1) and
You need to run in background explicitly if you use this option.
-sm[aster] | s[econdary]
Determines which server to switch away from. If this option is omitted,
the master goes down.