= pgbouncer(5) =

== NAME ==

pgbouncer - Lightweight connection pooler for PostgreSQL.

== SYNOPSIS ==

  [databases]
  db = ...

  [pgbouncer]
  ...

== DESCRIPTION == 

Config file is in "ini" format. Section names are between " and
". Lines starting with ";" or "#" are taken as comment and
ignored. The characters ";" and "#" are not recognized when they
appear later in the line.

== SECTION [pgbouncer] ==

=== Generic settings ===

==== logfile ====

Specifies log file. Log file is kept open so after rotation
`kill -HUP` or on console `RELOAD;` should be done.

Default: not set.

==== pidfile ====

Specifies pid file. Without pidfile, the daemonization is not allowed.

Default: not set.

==== listen_addr ====

Specifies IPv4 address, where to listen for TCP connections. Or `*`
meaning "listen on all addresses". When not set, only unix socket
connections are allowed.

Default: not set

==== listen_port ====

On which port to listen on. Applies to both TCP and Unix sockets.

Default: 6000

==== unix_socket_dir ====

Specifies location for Unix sockets. Applies to both listening socket and
server connections. If set to empty string, Unix sockets are disabled.

Default: +/tmp+

==== auth_file ====

Load user names and passwords from this file. File format used is same as for
PostgreSQL pg_auth/pg_pwd file, so can be pointed directly to backend file.

Default: not set.

==== auth_type ====

How to authenticate users.

md5::
      Use MD5-based password check. `auth_file` may contain both md5-encrypted
      or plain-text passwords.  Default.

crypt::
      Use crypt(3) based bassword check. `auth_file` must contain plain-text
      passwords.

plain::
      Clear-text password is sent over wire.

trust::
      No authentication is done. Username must still exists in `auth_file`.

any::
      Like `trust` but username given is ignored. Requires that all databases
      have configured to log in as specific user.

==== pool_mode ====

Specifies when server connection is tagged as reusable for other clients.

session::
      Server is released back to pool after client disconnects.  Default.

transaction::
      Server is released back to pool after transaction finishes.

statement::
      Server is released back to pool after query finishes. Long transactions
      spanning multiple statements are disallowed in this mode.

==== max_client_conn ====

Maximum number of client connections allowed.  When increased then the file
descriptor limits should also be increased.  Note that actual number of file
descriptiors used is more that max_client_conn.  Theoretical maximum used is:

  max_client_conn + (max_pool_size * total_databases * total_users)

if each user connects under it's own username to server.  If database user
is specified in connect string (all users connect under same username),
the theoretical maximum is:

  max_client_conn + (max_pool_size * total_databases)

The theoretical maximum should be never reached, unless somebody deliberately
crafts special load for it.  Still, it means you should give fds liberately.

Search for `ulimit` in your favourite shell man page.

Default: 100

==== default_pool_size ====

How many server connection to allow per user/database pair. Can be overrided in
per-database config.

Default: 20

==== server_round_robin ====

By default, pgbouncer reuses server connections in LIFO manner, so that few
connections get the most load.  This gives best performance if you have single
server serving a database.  But if there is TCP round-robin behind a database
IP then it's better if pgbouncer also uses connections in that manner, thus
achieving uniform load.

Default: 0

=== Log settings ===

==== log_connections ====

Log successful logins.

Default: 1

==== log_disconnections ====

Log disconnections with reasons.

Default: 1

==== log_pooler_errors ====

Log error messaged pooler sends to clients.

Default: 1

=== Console access control ===

==== admin_users ====

List of users that are allowed to run all commands on console.

Default: empty

==== stats_users ====

List of users that are allowed to run read-only queries on console. Thats means
all SHOW commands except SHOW FDS.

Default: empty.

=== Connection sanity checks, timeouts ===

==== server_reset_query ====

Query send to server on connection release, before making it
available to other clients.  At that moment no transaction is in
progress so it should not include `ABORT` or `ROLLBACK`.

Good choice for 8.2 and below is:

  server_reset_query = RESET ALL; SET SESSION AUTHORIZATION DEFAULT;

for 8.3 and above its enough to do:

  server_reset_query = DISCARD ALL;

==== server_check_delay ====

How long to keep released immidiately available, without running sanity-check
query on it. If 0 then the query is ran always.

Default: 30

==== server_check_query ====

Simple do-nothing query to check if server connection is alive.

If empty string, then sanity checking is disabled.

Default: SELECT 1;

==== server_lifetime ====

Pooler tries to close server connections that are been connected longer than
this.

Default: 3600

==== server_idle_timeout ====

If server connection has been idle more than this then there's too many
connections in the pool and this one can be dropped.

Default: 600

==== server_connect_timeout ====

If connection and login wont finish in this time, the connection will be
closed.

Default: 15

==== server_login_retry ====

If login failed, because of failure from connect() or authentication that
pooler waits this much before retrying to connect.

Default: 15

==== client_login_timeout ====

If client connect but does not manage to login in this time, it will be
disconnected. Mainly needed to avoid dead connections stalling SUSPEND and thus
online restart.

Default: 60

=== Dangerous timeouts ===

Setting following timeouts cause unexcpected errors.

==== query_timeout ====

Queries running longer than that are canceled. This should be used only with
slightly smaller server-side statement_timeout, to apply only for network
problems.

Default: 0 (disabled)

==== client_idle_timeout ====

Client connections idling longer than that are closed. This should be larger
then client-side connection lifetime settings, to apply only for network
problems.

Default: 0 (disabled)

=== Low-level network settings ===

==== pkt_buf ====

Internal buffer size for packets. Affects size of TCP packets sent and general
memory usage. Actual libpq packets can be larger than this so no need to set it
large.

Default: 2048

==== tcp_defer_accept ====

Details about following options shouldbe looked from man 7 tcp

Default: 45 on Linux, otherwise 0

==== tcp_socket_buffer ====

Default: not set

==== tcp_keepalive ====

Default: Not set

==== tcp_keepcnt ====

Default: not set

==== tcp_keepidle ====

Default: not set

==== tcp_keepintvl ====

Default: not set

== SECTION [databases] ==

This contains key=value pairs where key will be taken as database name and
value as libpq-connstring style list of key=value pairs. As actual libpq is not
used, so not all features from libpq can be used (service=, quoting).

=== Location parameters ===

==== dbname ====

Destination database name.

Default: same as client-side database name.

==== host ====

IP-address to connect to.

Default: not set, meaning to use unix-socket.

==== port ====

Default: 5432

==== user, password ====

If +user=+ is set, all connections to destination database will be
done with that user, meaning that there will be only one pool for this
database.

Otherwise pgbouncer tries to log into destination database with client
username, meaning that there will be one pool per user.

=== Per-database pool Size ===

==== pool_size ====

Set maximum size of pools for this database.  If not set,
the default_pool_size is used.

=== Extra parameters ===

They allow setting default parameters on server connection.

Note that since version 1.1 PgBouncer tracks client
changes for their values, so their use in pgbouncer.ini
is deprecated now.

==== client_encoding ====

Ask specific +client_encoding+ from server.

==== datestyle ====

Ask specific +datestyle+ from server.

==== timezone ====

Ask specific +timezone+ from server.

== Example ==

=== Minimal config ===

  [databases]
  template1 = host=127.0.0.1 dbname=template1

  [pgbouncer]
  pool_mode = session
  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
  stats_users = stat_collector

=== Database defaults ===

  [databases]

  ; foodb over unix socket
  foodb =

  ; redirect bardb to bazdb on localhost
  bardb = host=127.0.0.1 dbname=bazdb

  ; acceess to dest database will go with single user
  forcedb = host=127.0.0.1 port=300 user=baz password=foo client_encoding=UNICODE datestyle=ISO

== SEE ALSO ==

pgbouncer(1)

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

