xenial (1) pgbouncer.1.gz

Provided by: pgbouncer_1.7-1_amd64 bug

NAME

       pgbouncer - lightweight connection pooler for PostgreSQL

SYNOPSIS

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

       On Windows computers, the options are:

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

       Additional options for setting up a Windows service:

       pgbouncer.exe --regservice   <pgbouncer.ini>
       pgbouncer.exe --unregservice <pgbouncer.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 create a connection to the  actual  server,  or  it  will
       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 types
       of pooling when rotating connections:

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

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

       Statement pooling
              Most aggressive method. The server connection will be put back into pool immediately 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 a pgbouncer.ini file.  Details in pgbouncer(5).  Simple example:

          [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 that contains users allowed in:

          "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 -p 6543 -U someuser template1

       5. Manage pgbouncer by connecting to the special administration database pgbouncer and issuing show help;
          to begin:

          $ psql -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 made changes to the pgbouncer.ini file, you can reload it with:

          pgbouncer=# RELOAD;

COMMAND LINE SWITCHES

       -d     Run in background. Without it the process will run in foreground.  Note: Does not work on Windows,
              pgbouncer need to run as service there.

       -R     Do an online restart. That means connecting to the running process, loading the open sockets  from
              it,  and  then  using them.  If there is no active process, boot normally.  Note: Works only if OS
              supports Unix sockets and the unix_socket_dir is not disabled in config.  Does not work on Windows
              machines.  Does not work with TLS connections, they are dropped.

       -u user
              Switch to the given user on startup.

       -v     Increase verbosity.  Can be used multiple times.

       -q     Be quiet - do not 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.

       --regservice
              Win32: Register pgbouncer to run as Windows service.  The service_name config parameter  value  is
              used as name to register under.

       --unregservice
              Win32: Unregister Windows service.

ADMIN CONSOLE

       The console is available by connecting as normal to the database pgbouncer:

       $ psql -p 6543 pgbouncer

       Only  users  listed  in  configuration  parameters admin_users or stats_users are allowed to login to the
       console.  (Except when auth_mode=any, then any user is allowed in as a stats_user.)

       Additionally, the 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 information. Each command is described below.

   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 microseconds 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 microseconds.

   SHOW SERVERS;
       type   S, for server.

       user   Username pgbouncer uses to connect to server.

       database
              Database name.

       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.

       remote_pid
              Pid  of  backend  server  process.   In  case  connection is made over unix socket and OS supports
              getting process ID info, it's OS pid.  Otherwise it's extracted from cancel  packet  server  sent,
              which should be PID in case server is Postgres, but it's a random number in case server it another
              PgBouncer.

   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 connect time.

       request_time
              Timestamp of latest client request.

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

       link   Address of server connection the client is paired with.

       remote_pid
              Process ID, in case client connects over UNIX socket and OS supports getting it.

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

       database
              Database name.

       user   User name.

       cl_active
              Client connections that are linked to server connection and can process queries.

       cl_waiting
              Client connections have sent queries but have not yet got a server connection.

       sv_active
              Server connections that linked to client.

       sv_idle
              Server connections that unused and immediately usable for client queries.

       sv_used
              Server  connections  that  have  been  idle  more   than   server_check_delay,   so   they   needs
              server_check_query to run on it before it can be used.

       sv_tested
              Server connections that are currently running either server_reset_query or server_check_query.

       sv_login
              Server connections currently in logging in process.

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

       pool_mode
              The pooling mode in use.

   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;
       name   The user name

       pool_mode
              The user's override pool_mode, or NULL if the default will be used instead.

   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.

       pool_mode
              The database's override pool_mode, or NULL if the default will be used instead.

   SHOW FDS;
       Internal command - shows list of fds in use with internal state attached to them.

       When the connected user has username "pgbouncer", connects through  Unix  socket  and  has  same  UID  as
       running  process,  the actual fds are passed over the connection.  This mechanism is used to do an online
       restart.  Note: This does not work on Windows machines.

       This command also blocks internal event loop, so it should not be used while PgBouncer is in use.

       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  Configuration value

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

   SHOW DNS_HOSTS;
       Show hostnames in DNS cache.

       hostname
              Host name.

       ttl    How meny seconds until next lookup.

       addrs  Comma separated list of addresses.

   SHOW DNS_ZONES
       Show DNS zones in cache.

       zonename
              Zone name.

       serial Current serial.

       count  Hostnames belonging to this zone.

   Process controlling commands
   PAUSE [db];
       PgBouncer  tries  to  disconnect from all servers, first waiting for all queries to complete. The command
       will not return before all queries are finished.  To be used at the time of database restart.

       If database name is given, only that database will be paused.

   DISABLE db;
       Reject all new client connections on the given database.

   ENABLE db;
       Allow new client connections after a previous DISABLE command.

   KILL db;
       Immediately drop all client and server connections on given database.

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

   RESUME [db];
       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://pgbouncer.github.io/

       https://wiki.postgresql.org/wiki/PgBouncer