Provided by: pgbouncer_1.3-1_i386 bug

NAME

       pgbouncer - Lightweight connection pooler for PostgreSQL.

SYNOPSIS

       pgbouncer [-d][-R][-v][-u user] <pgbouncer.ini>
       pgbouncer -V|-h

       The windows environment serves as the following options.

       pgbouncer.exe [-v][-u user] <pgbouncer.ini>
       pgbouncer.exe -V|-h

       Furthermore, this option is specially offered for windows-service.

       <windows service registration>
        -regservice   [servicename]
        -unregservice [servicename]
        -listengines  [servicename]
        -addengine    [servicename] config.ini
        -delengine    [servicename] config.ini

DESCRIPTION

       pgbouncer is a PostgreSQL connection pooler. Any target application can
       be connected to pgbouncer as if it were a PostgreSQL server, and
       pgbouncer will manage to connect to the server, or to reuse one of its
       existing connections.

       The aim of pgbouncer is to lower the performance impact of opening new
       connections to PostgreSQL.

       In order not to compromise transaction semantics for connection
       pooling, pgbouncer supports several levels of brutality when rotating
       connections:

       Session pooling
           Most polite method. When client connects, a server connection will
           be assigned to it for the whole duration it stays connected. When
           client disconnects, the server connection will be put back into
           pool.

       Transaction pooling
           Server connection is assigned to client only during a transaction.
           When PgBouncer notices that transaction is over, the server will be
           put back into pool.

       Statement pooling
           Most aggressive method. The server connection will be put back into
           pool immidiately after a query completes. Multi-statement
           transactions are disallowed in this mode as they would break.

       The administration interface of pgbouncer consists of some new SHOW
       commands available when connected to a special virtual database
       pgbouncer.

QUICK-START

       Basic setup and usage as following.

        1. Create config file. Details in pgbouncer(5). Simplest:

               [databases]
               template1 = host=127.0.0.1 port=5432 dbname=template1

               [pgbouncer]
               listen_port = 6543
               listen_addr = 127.0.0.1
               auth_type = md5
               auth_file = users.txt
               logfile = pgbouncer.log
               pidfile = pgbouncer.pid
               admin_users = someuser

        2. Create users.txt file:

               "someuser" "same_password_as_in_server"

        3. Launch pgbouncer:

               $ pgbouncer -d pgbouncer.ini

        4. have your application (or the psql client) connect to pgbouncer
           instead of directly to PostgreSQL server.

               $ psql -h 127.0.0.1 -p 6543 -U someuser template1

        5. manage pgbouncer by connecting to special administration database
           pgbouncer and issue show help; to begin:

               $ psql -h 127.0.0.1 -p 6543 -U someuser pgbouncer
               pgbouncer=# show help;
               NOTICE:  Console usage
               DETAIL:
                 SHOW [HELP|CONFIG|DATABASES|FDS|POOLS|CLIENTS|SERVERS|SOCKETS|LISTS|VERSION]
                 SET key = arg
                 RELOAD
                 PAUSE
                 SUSPEND
                 RESUME
                 SHUTDOWN

        6. If you change some changeable configuration settings in the
           configuration file, you can reload the file with:

               pgbouncer=# RELOAD;

COMMAND LINE SWITCHES

       -d
           Run in background. Without it the process will run in foreground.
           Note: The windows environment should use the special option for
           service operation.

       -R
           Do a online restart. That means connecting to running process,
           loading open sockets from it and using them. If there is no active
           process, boot normally. Note: The windows environment is not
           equipped.

       -u user
           Switch to user on startup.

       -v
           Increase verbosity. Can be used multiple times.

       -q
           Be quiet - don’t log to stdout. Note this does not affect logging
           verbosity, only that stdout is not to be used. For use in init.d
           scripts.

       -V
           Show version.

       -h
           Show short help.

ADMIN CONSOLE

       Console is available by connecting into standard
       listen_addr/listen_port and specifying string pgbouncer as database.

           $ psql -h 127.0.0.1 -p 6543 pgbouncer

       Only users listed in configuration parameters admin_users or
       stats_users are allowed to login to the console.

       Additionally, username pgbouncer is allowed to log in without password,
       if the login comes via UNIX socket and the client has same UNIX user
       uid as the running process.

   SHOW COMMANDS
       The SHOW commands output some rows, the columns contained are described
       here.

       SHOW STATS;
           Shows statistics.

           database
               Statistics are presented per database.

           total_requests
               Total number of SQL requests pooled by pgbouncer.

           total_received
               Total volume in bytes of network traffic received by pgbouncer.

           total_sent
               Total volume in bytes of network traffic sent by pgbouncer.

           total_query_time
               Total number of milliseconds spent by pgbouncer when actively
               connected to PostgreSQL.

           avg_req
               Average requests per second in last stat period.

           avg_recv
               Average received (from clients) bytes per second.

           avg_sent
               Average sent (to clients) bytes per second.

           avg_query
               Average query duration in milliseconds.

       SHOW SERVERS;
           type
               S, for server.

           user
               Username pgbouncer uses to connect to server.

           database
               database name on server.

           state
               State of the pgbouncer server connection, one of active, used
               or idle.

           addr
               IP address of PostgreSQL server.

           port
               Port of PostgreSQL server.

           local_addr
               Connection start address on local machine.

           local_port
               Connection start port on local machine.

           connect_time
               When the connection was made.

           request_time
               When last request was issued.

           ptr
               Address of internal object for this connection. Used as unique
               ID.

           link
               Address of client connection the server is paired with.

       SHOW CLIENTS;
           type
               C, for client.

           user
               Client connected user.

           database
               database name.

           state
               State of the client connection, one of active, used, waiting or
               idle.

           addr
               IP address of client.

           port
               port client is connected to.

           local_addr
               Connection end address on local machine.

           local_port
               Connection end port on local machine.

           connect_time
               Timestamp of later client connection.

           request_time
               Timestamp of later client request.

           ptr
               Address of internal object for this connection. Used as unique
               ID.

           link
               Address of server connection the client is paired with.

       SHOW POOLS;
           A new pool entry is made for each couple of (database, user).

           database
               database name.

           user
               username.

           cl_active
               Count of currently active client connections.

           cl_waiting
               Count of currently waiting client connections.

           sv_active
               Count of currently active server connections.

           sv_idle
               Count of currently idle server connections.

           sv_used
               Count of currently used server connections.

           sv_tested
               Count of currently tested server connections.

           sv_login
               Count of server connections currently login to PostgreSQL.

           maxwait
               How long has first (oldest) client in queue waited, in second.
               If this start increasing, then current pool of servers does not
               handle requests quick enough. Reason may be either overloaded
               server or just too small pool_size.

       SHOW LISTS;
           Show following internal information, in columns (not rows):

           databases
               Count of databases.

           users
               Count of users.

           pools
               Count of pools.

           free_clients
               Count of free clients.

           used_clients
               Count of used clients.

           login_clients
               Count of clients in login state.

           free_servers
               Count of free servers.

           used_servers
               Count of used servers.

       SHOW USERS;
           Show one line per user, under the name column name.

       SHOW DATABASES;
           name
               name of configured database entry.

           host
               Host pgbouncer connects to.

           port
               Port pgbouncer connects to.

           database
               Actual database name pgbouncer connects to.

           force_user
               When user is part of the connection string, the connection
               between pgbouncer and PostgreSQL is forced to the given user,
               whatever the client user.

           pool_size
               Maximum number of server connections.

       SHOW FDS;
           Shows list of fds in use. When the connected user has username
           "pgbouncer", connects thru unix socket and has same UID as running
           process, the actual fds are passed over connection. This mechanism
           is used to do online restart. Note: The windows environment is not
           supported.

           fd
               File descriptor numeric value.

           task
               One of pooler, client or server.

           user
               User of the connection using the FD.

           database
               database of the connection using the FD.

           addr
               IP address of the connection using the FD, unix if a unix
               socket is used.

           port
               port used by the connection using the FD.

           cancel
               cancel key for this connection.

           link
               fd for corresponding server/client. NULL if idle.

       SHOW CONFIG;
           Show the current configuration settings, one per row, with
           following columns:

           key
               configuration variable name

           value
               configures value

           changeable
               Either yes or no, shows if the variable is changeable when
               running. If no, the variable can be changed only boot-time.

   PROCESS CONTROLLING COMMANDS
       PAUSE;
           PgBouncer tries to disconnect from all servers, first waiting for
           all queries to complete. The command will not return before all is
           done. To be used at the time of database restart.

       SUSPEND;
           All socket buffers are flushed and PgBouncer stops listening data
           on them. The command will not return before all is done. To be used
           at the time of PgBouncer restart.

       RESUME;
           Resume work from previous PAUSE or SUSPEND command.

       SHUTDOWN;
           The PgBouncer process will exit.

       RELOAD;
           The PgBouncer process will reload its configuration file and update
           changeable settings.

   SIGNALS
       SIGHUP
           Reload config. Same as issuing command RELOAD; on console.

       SIGINT
           Safe shutdown. Same as issuing PAUSE; and SHUTDOWN; on console.

       SIGTERM
           Immediate shutdown. Same as issuing SHUTDOWN; on console.

   LIBEVENT SETTINGS
       From libevent docs:

           It is possible to disable support for epoll, kqueue, devpoll, poll
           or select by setting the environment variable EVENT_NOEPOLL,
           EVENT_NOKQUEUE, EVENT_NODEVPOLL, EVENT_NOPOLL or EVENT_NOSELECT,
           respectively.

           By setting the environment variable EVENT_SHOW_METHOD, libevent
           displays the kernel notification method that it uses.

SEE ALSO

       pgbouncer(5) - manpage of configuration settings descriptions.

       https://developer.skype.com/SkypeGarage/DbProjects/PgBouncer

[FIXME: source]                   05/05/2009                      PGBOUNCER(1)