pgbouncer — a Postgres Pro connection pooler
On Linux systems:
pgbouncer [ -d ] [ -R ] [ -v ] [ -u user ] pgbouncer.ini
pgbouncer -V | -h
On Windows systems:
pgbouncer [ -v ] [ -u user ] pgbouncer.ini
pgbouncer -V | -h
To use pgbouncer as a Windows service:
pgbouncer.exe --regservice pgbouncer.ini
pgbouncer.exe --unregservice pgbouncer.ini
pgbouncer is a Postgres Pro connection pooler. Any target application can be connected to pgbouncer as if it were a Postgres Pro 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 Postgres Pro.
In order not to compromise transaction semantics for connection pooling, pgbouncer supports several types of pooling when rotating connections:
Most polite method. When a 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.
A server connection is assigned to a client only during a transaction. When pgbouncer notices that transaction is over, the server connection will be put back into the pool.
Most aggressive method. The server connection will be put back into the 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.
Basic setup and usage is as follows.
Create a pgbouncer.ini file. Details
in the pgbouncer(5) man page. 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 = userlist.txt logfile = pgbouncer.log pidfile = pgbouncer.pid admin_users = someuser
Create a userlist.txt file that contains the users allowed in:
"someuser" "same_password_as_in_server"
Launch pgbouncer:
$ pgbouncer -d pgbouncer.ini
The above command does not work on Windows systems. Instead, pgbouncer must be launched as a service that first needs to be registered, as follows:
pgbouncer --regservice
Have your application (or the
psql client) connect to
pgbouncer instead of
directly to the Postgres Pro server:
$ psql -p 6543 -U someuser template1
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 [...]
If you made changes to the pgbouncer.ini file, you can reload
it with:
pgbouncer=# RELOAD;
-d
Run in the background. Without it, the process will run in the foreground.
Does not work on Windows, pgbouncer needs 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.
Works only if OS supports Unix sockets and the
unix_socket_dir is not disabled in configuration. Does not work on
Windows. 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.
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 to run as Windows service. The
service_name configuration
parameter value is used as the name to register under.
--unregservice
Win32: Unregister Windows service.
The console is available by connecting as normal to the database pgbouncer:
$ psql -p 6543 pgbouncer
Only users listed in the configuration parameters
admin_users or
stats_users are allowed to
log in to the console. (Except when auth_mode=any, then any user is
allowed in as a stats_user.)
Additionally, the user name
pgbouncer is allowed to log in
without password, if the login comes via the Unix socket and the
client has same Unix user uid as the running process.
The SHOW commands output
information. Each command is described below.
Shows statistics. In this and related commands, the total figures are
since process start, the averages are updated every stats_period.
database
Statistics are presented per database.
total_xact_count
Total number of SQL transactions pooled by pgbouncer.
total_query_count
Total number of SQL queries 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_xact_time
Total number of microseconds spent by pgbouncer when connected to Postgres Pro in a transaction, either idle in transaction or executing queries.
total_query_time
Total number of microseconds spent by pgbouncer when actively connected to Postgres Pro, executing queries.
total_wait_time
Time spent by clients waiting for a server, in microseconds.
avg_xact_count
Average transactions per second in last stat period.
avg_query_count
Average queries 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_xact_time
Average transaction duration, in microseconds.
avg_query_time
Average query duration, in microseconds.
avg_wait_time
Time spent by clients waiting for a server, in microseconds (average per second).
Subset of SHOW STATS showing the
total values (total_).
Subset of SHOW STATS showing the
average values (avg_).
Like SHOW STATS but aggregated
across all databases.
type
S, for server.
user
User name 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 Postgres Pro server.
port
Port of Postgres Pro 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.
wait
Current waiting time in seconds.
wait_us
Microsecond part of the current waiting time.
close_needed
1 if the connection will be closed as soon as possible,
because a configuration file reload or DNS update changed the
connection information or RECONNECT 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, its OS PID. Otherwise it's extracted from cancel packet the server sent, which should be the PID in case the server is Postgres Pro, but it's a random number in case the server is another pgbouncer.
tls
A string with TLS connection information, or empty if not using TLS.
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.
wait
Current waiting time in seconds.
wait_us
Microsecond part of the current waiting time.
close_needed
Not used for clients.
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.
tls
A string with TLS connection information, or empty if not using TLS.
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 a client.
sv_idle
Server connections that are unused and immediately usable for client queries.
sv_used
Server connections that have been idle for more than
server_check_delay, so they need server_check_query to
run on them before they can be used again.
sv_tested
Server connections that are currently running either
server_reset_query or server_check_query.
sv_login
Server connections currently in the process of logging in.
maxwait
How long the first (oldest) client in the queue has waited,
in seconds. If this starts increasing, then the current
pool of servers does not handle requests quickly enough.
The reason may be either an overloaded server or just too small
of a pool_size
setting.
maxwait_us
Microsecond part of the maximum waiting time.
pool_mode
The pooling mode in use.
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.
dns_names
Count of DNS names in the cache.
dns_zones
Count of DNS zones in the cache.
dns_queries
Count of in-flight DNS queries.
dns_pending
Not used.
name
The user name.
pool_mode
The user's override pool_mode, or NULL if the default
will be used instead.
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 the user is part of the connection string, the connection between pgbouncer and Postgres Pro is forced to the given user, whatever the client user.
pool_size
Maximum number of server connections.
reserve_pool
Maximum number of additional connections for this database.
pool_mode
The database's override pool_mode, or NULL if the
default will be used instead.
max_connections
Maximum number of allowed connections for this database, as set by
max_db_connections, either globally or per database.
current_connections
Current number of connections for this database.
paused
1 if this database is currently paused, else 0.
disabled
1 if this database is currently disabled, else 0.
Internal command — shows list of file descriptors (FDs) in use with internal state attached to them.
When the connected user has the user name pgbouncer,
connects through the Unix socket and has the same UID as the running
process, the actual FDs are passed over the connection. This
mechanism is used to do an online restart.
This does not work on Windows systems.
This command also blocks the 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
File descriptor for corresponding server/client. NULL if idle.
Shows low-level information about sockets or only active sockets.
This includes the information shown under SHOW CLIENTS
and SHOW SERVERS as well as other more low-level information.
Show the current configuration settings, one per row, with the 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 at boot-time. Use
SET to change a variable at run time.
Shows low-level information about the current sizes of various internal memory allocations. The information presented is subject to change.
Show host names in DNS cache.
hostname
Host name.
ttl
How many seconds until next lookup.
addrs
Comma separated list of addresses.
Show DNS zones in cache.
zonename
Zone name.
serial
Current serial.
count
Host names belonging to this zone.
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.
New client connections to a paused database will wait until
RESUME is called.
dbReject all new client connections on the given database.
db
Allow new client connections after a previous
DISABLE command.
dbClose each open server connection for the given database, or all databases, after it is released (according to the pooling mode), even if its lifetime is not up yet. New server connections can be made immediately and will connect as necessary according to the pool size settings.
This command is useful when the server connection setup has changed,
for example to perform a gradual switchover to a new server. It is
not necessary to run this command when the connection string in
pgbouncer.ini has been changed and reloaded
(see RELOAD) or when DNS resolution has changed,
because then the equivalent of this command will be run automatically.
This command is only necessary if something downstream of
pgbouncer routes the connections.
After this command is run, there could be an extended period where
some server connections go to an old destination and some server
connections go to a new destination. This is likely only sensible
when switching read-only traffic between read-only replicas, or when
switching between nodes of a multimaster replication setup. If all
connections need to be switched at the same time, PAUSE is
recommended instead. To close server connections without waiting (for
example, in emergency failover rather than gradual switchover
scenarios), also consider KILL.
dbImmediately drop all client and server connections on given database.
New client connections to a killed database will wait until
RESUME is called.
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.
New client connections to a suspended database will wait until
RESUME is called.
db]
Resume work from previous KILL,
PAUSE, or
SUSPEND command.
The pgbouncer process will exit.
The pgbouncer process will reload its configuration file and update changeable settings.
PgBouncer notices when a configuration file reload changes the connection parameters of a database definition. An existing server connection to the old destination will be closed when the server connection is next released (according to the pooling mode), and new server connections will immediately use the updated connection parameters.
db]
Wait until all server connections, either of the specified database or
of all databases, have cleared the close_needed state
(see the section called “SHOW SERVERS”). This can be called after
a RECONNECT or RELOAD to
wait until the respective configuration change has been fully
activated, for example in switchover scripts.
key = argChanges a configuration setting (see also the section called “SHOW CONFIG”). For example:
SET log_connections = 1; SET server_check_query = 'select 2';
(Note that this command is run on the pgbouncer
admin console and sets pgbouncer settings.
A SET command run on another database will be
passed to the Postgres Pro backend like any other SQL command.)
SIGHUP
Reload config. Same as issuing the command
RELOAD on the console.
SIGINT
Safe shutdown. Same as issuing
PAUSE and
SHUTDOWN on the console.
SIGTERM
Immediate shutdown. Same as issuing
SHUTDOWN on the console.
SIGUSR1
Same as issuing PAUSE on the console.
SIGUSR2
Same as issuing RESUME on the console.
From the libevent documentation:
It is possible to disable support for
epoll,kqueue,devpoll,poll, orselectby setting the environment variableEVENT_NOEPOLL,EVENT_NOKQUEUE,EVENT_NODEVPOLL,EVENT_NOPOLLorEVENT_NOSELECT, respectively.By setting the environment variable
EVENT_SHOW_METHOD,libeventdisplays the kernel notification method that it uses.
pgbouncer.ini Configuration File
The configuration file is in the .ini format. Section names are
between "[" and "]". Lines starting with
";" or "#" are taken as comments and ignored.
The characters ";" and "#" are not recognized
when they appear later in the line.
logfile
Specifies log file. Log file is kept open so after rotation
kill -HUP or on console
RELOAD; should be done. Note: On Windows
systems, the service must be stopped and started.
Default: not set
pidfile
Specifies the PID file. Without a pidfile, daemonization is not
allowed.
Default: not set
listen_addr
Specifies list of addresses, where to listen for TCP
connections. You may also use * meaning
"listen on all addresses". When not set, only Unix
socket connections are allowed.
Addresses can be specified numerically (IPv4/IPv6) or by name.
Default: not set
listen_portWhich port to listen on. Applies to both TCP and Unix sockets.
Default: 6432
unix_socket_dirSpecifies location for Unix sockets. Applies to both listening socket and server connections. If set to an empty string, Unix sockets are disabled. Required for online reboot (-R) to work. Note: Not supported on Windows systems.
Default: /tmp
unix_socket_modeFile system mode for Unix socket.
Default: 0777
unix_socket_groupGroup name to use for Unix socket.
Default: not set
userIf set, specifies the Unix user to change to after startup. Works only if pgbouncer is started as root or if it's already running as given user.
Note: Not supported on Windows systems.
Default: not set
auth_fileThe name of the file to load user names and passwords from. See the section called “Authentication File Format” for details.
Default: not set
auth_hba_file
HBA configuration file to use when auth_type is
hba. Supported from version 1.7 onwards.
Default: not set
auth_typeHow to authenticate users.
pam
Pluggable Authentication Modules (PAM) method is used to authenticate users, auth_file is ignored.
This method is not compatible with databases using
auth_user option. Service name reported to PAM is
pgbouncer. Also, PAM is still not supported in
HBA configuration file.
hba
Actual authentication type is loaded from auth_hba_file. This
allows different authentication methods different access
paths. Example: connection over Unix socket uses
peer authentication method, connection over TCP
must use TLS. Supported from version 1.7 onwards.
cert
Client must connect over TLS connection with valid client certificate. Username is then taken from CommonName field from certificate.
md5
Use MD5-based password check. This is the default authentication
method. auth_file may contain both
MD5-encrypted or plain-text passwords. If md5
is configured and a user has a SCRAM secret, then SCRAM
authentication is used automatically instead.
scram-sha-256
Use password check with SCRAM-SHA-256.
auth_file has to contain
SCRAM secrets or plain-text passwords. Note that SCRAM secrets
can only be used for verifying the password of a client but not
for logging into a server. To be able to use SCRAM on server
connections, use plain-text passwords.
plain
Clear-text password is sent over wire. Deprecated.
trust
No authentication is done. Username must still exist in
auth_file.
any
Like the trust method, but the username
given is ignored. Requires that all databases are
configured to log in as specific user. Additionally, the
console database allows any user to log in as admin.
auth_queryQuery to load user's password from database.
Direct access to pg_shadow requires admin rights. It's
preferable to use non-admin user that calls SECURITY DEFINER
function instead.
Note that the query is run inside target database, so if a function is used it needs to be installed into each database.
Default:
SELECT usename, passwd FROM pg_shadow WHERE usename=$1
auth_user
If auth_user is set, any user not specified
in auth_file will be queried through the
auth_query query from pg_shadow
in the database using auth_user.
auth_user's password will be taken from auth_file.
Direct access to pg_shadow requires admin rights. It's
preferable to use non-admin user that calls SECURITY DEFINER
function instead.
Default: not set
pool_modeSpecifies when a server connection can be reused by 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,
the file descriptor limits should also be increased. Note
that actual number of file descriptors used is more than
max_client_conn. If each user connects under its own username to server, theoretical maximum used is:
max_client_conn + (max pool_size * total databases * total users)
If a 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 set the number of file descriptors to a safely high number.
Search for ulimit in your favorite shell man
page. Note: ulimit does not apply in a
Windows environment.
Default: 100
default_pool_sizeHow many server connections to allow per user/database pair. Can be overridden in the per-database configuration.
Default: 20
min_pool_sizeAdd more server connections to pool if below this number. Improves behavior when usual load suddenly comes back after a period of total inactivity.
Default: 0 (disabled)
reserve_pool_sizeHow many additional connections to allow to a pool. The 0 value disables this parameter.
Default: 0 (disabled)
reserve_pool_timeoutIf a client has not been serviced in this many seconds, pgbouncer enables use of additional connections from reserve pool. The 0 value disables this parameter.
Default: 5.0
max_db_connectionsDo not allow more than this many connections per-database (regardless of pool — i.e. user). It should be noted that when you hit the limit, closing a client connection to one pool will not immediately allow a server connection to be established for another pool, because the server connection for the first pool is still open. Once the server connection closes (due to idle timeout), a new server connection will immediately be opened for the waiting pool.
Default: unlimited
max_user_connectionsDo not allow more than this many connections per-user (regardless of pool — i.e. user). It should be noted that when you hit the limit, closing a client connection to one pool will not immediately allow a server connection to be established for another pool, because the server connection for the first pool is still open. Once the server connection closes (due to idle timeout), a new server connection will immediately be opened for the waiting pool.
server_round_robinBy default, pgbouncer reuses server connections in LIFO (last-in, first-out) manner, so that few connections get the most load. This gives best performance if you have a single server serving a database. But if there is TCP round-robin behind a database IP, then it is better if pgbouncer also uses connections in that manner, thus achieving uniform load.
Default: 0
ignore_startup_parameters
By default, pgbouncer allows only parameters it can keep track
of in startup packets — client_encoding,
datestyle, timezone and
standard_conforming_strings.
All other parameters will raise an error. To allow other parameters, they can be specified here, so that pgbouncer knows that they are handled by admin and it can ignore them.
Default: empty
disable_pqexecDisable Simple Query protocol (PQexec). Unlike Extended Query protocol, Simple Query allows multiple queries in one packet, which allows some classes of SQL-injection attacks. Disabling it can improve security. Obviously this means only clients that exclusively use Extended Query protocol will stay working.
Default: 0
application_name_add_host
Add the client host address and port to the application name
setting set on connection start. This helps in identifying the
source of bad queries, etc. This logic applies only on start of
connection, if application_name is later changed with SET,
pgbouncer does not change it again.
Default: 0
conffile
Show location of current configuration file. Changing it will make
pgbouncer use another configuration file for next
RELOAD / SIGHUP.
Default: file from command line.
service_nameUsed on win32 service registration.
Default: pgbouncer
job_name
Alias for service_name.
stats_period
Sets how often the averages shown in various
SHOW commands are updated and how often
aggregated statistics are written to the log
(but see log_stats). [seconds]
Default: 60
syslogToggles syslog on/off. On Windows systems, eventlog is used instead.
Default: 0
syslog_identUnder what name to send logs to syslog.
Default: pgbouncer (program name)
syslog_facility
Under what facility to send logs to syslog. Possibilities:
auth, authpriv,
daemon, user,
local0-7.
Default: daemon
log_connectionsLog successful logins.
Default: 1
log_disconnectionsLog disconnections with reasons.
Default: 1
log_pooler_errorsLog error messages pooler sends to clients.
Default: 1
stats_periodPeriod for writing aggregated stats into log.
Default: 60
log_stats
Write aggregated statistics into the log, every
stats_period. This can be disabled if
external monitoring tools are used to grab the same data
from SHOW commands.
Default: 1
verbose
Increase verbosity. Mirrors "-v" switch on command
line. Using "-v -v" on command line is same as
verbose=2 in configuration file.
Default: 0
admin_users
Comma-separated list of database users that are allowed to
connect and run all commands on console. Ignored when auth_type
is any, in which case any username is allowed
in as admin.
Default: empty
stats_usersComma-separated list of database users that are allowed to connect and run read-only queries on console. That means all SHOW commands except SHOW FDS.
Default: empty.
server_reset_query
Query sent 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.
The query is supposed to clean any changes made to database
session so that next client gets connection in well-defined
state. Default is DISCARD ALL which cleans
everything, but that leaves next client no pre-cached state. It
can be made lighter, e.g. DEALLOCATE ALL to
just drop prepared statements, if application does not break
when some state is kept around.
When transaction pooling is used, the server_reset_query is not
used, as clients must not use any session-based features as each
transaction ends up in different connection and thus gets
different session state.
Default: DISCARD ALL
server_reset_query_always
Whether server_reset_query should be run in all pooling modes.
When this setting is off (default), the server_reset_query will
be run only in pools that are in sessions-pooling mode.
Connections in transaction-pooling mode should not have any need
for reset query.
It is workaround for broken setups that run apps that use session features over transaction-pooled pgbouncer. It changes non-deterministic breakage to deterministic breakage — client always lose their state after each transaction.
Default: 0
server_check_delayHow long to keep released connections available for immediate re-use, without running sanity-check queries on it. If 0 then the query is always run.
Default: 30.0
server_check_querySimple do-nothing query to check if the server connection is alive.
If an empty string, then sanity checking is disabled.
Default: SELECT 1;
server_fast_close
Disconnect a server in session pooling mode immediately or after the
end of the current transaction if it is in close_needed mode (set by
RECONNECT, RELOAD that changes connection settings, or DNS
change), rather than waiting for the session end. In statement or
transaction pooling mode, this has no effect since that is the default
behavior there.
If because of this setting a server connection is closed before the end of the client session, the client connection is also closed. This ensures that the client notices that the session has been interrupted.
This setting makes connection configuration changes take effect sooner if session pooling and long-running sessions are used. The downside is that client sessions are liable to be interrupted by a configuration change, so client applications will need logic to reconnect and reestablish session state. But note that no transactions will be lost, because running transactions are not interrupted, only idle sessions.
Default: 0
server_lifetimeThe pooler will close an unused server connection that has been connected longer than this. Setting it to 0 means the connection is to be used only once, then closed. [seconds]
Default: 3600.0
server_idle_timeoutIf a server connection has been idle more than this many seconds it will be dropped. If 0 then timeout is disabled. [seconds]
Default: 600.0
server_connect_timeoutIf connection and login won't finish in this amount of time, the connection will be closed. [seconds]
Default: 15.0
server_login_retryIf login failed, because of failure from connect() or authentication that pooler waits this much before retrying to connect. [seconds]
Default: 15.0
client_login_timeoutIf a client connects but does not manage to login in this amount of time, it will be disconnected. Mainly needed to avoid dead connections stalling SUSPEND and thus online restart. [seconds]
Default: 60.0
autodb_idle_timeoutIf the automatically created (via "*") database pools have been unused this many seconds, they are freed. The negative aspect of that is that their statistics are also forgotten. [seconds]
Default: 3600.0
dns_max_ttlHow long the DNS lookups can be cached. If a DNS lookup returns several answers, pgbouncer will robin-between them in the meantime. Actual DNS TTL is ignored. [seconds]
Default: 15.0
dns_nxdomain_ttlHow long error and NXDOMAIN DNS lookups can be cached. [seconds]
Default: 15.0
dns_zone_check_periodPeriod to check if zone serial has changed.
pgbouncer can collect DNS zones from host names (everything after first dot) and then periodically check if zone serial changes. If it notices changes, all host names under that zone are looked up again. If any host IP changes, it's connections are invalidated.
Works only with UDNS and c-ares backends (--with-udns
or --with-cares to configure).
Default: 0.0 (disabled)
client_tls_sslmode
TLS mode to use for connections from clients. TLS connections
are disabled by default. When enabled, client_tls_key_file and
client_tls_cert_file must be also configured to set up key and
cert pgbouncer uses to accept client connections.
disable
Plain TCP. If client requests TLS, it's ignored. Default.
allow
If client requests TLS, it is used. If not, plain TCP is used. If client uses client-certificate, it is not validated.
prefer
Same as allow.
require
Client must use TLS. If not, client connection is rejected. If client uses client-certificate, it is not validated.
verify-ca
Client must use TLS with valid client certificate.
verify-full
Same as verify-ca.
client_tls_key_filePrivate key for pgbouncer to accept client connections.
Default: not set.
client_tls_cert_fileCertificate for private key. Clients can validate it.
Default: not set.
client_tls_ca_fileRoot certificate file to validate client certificates.
Default: unset.
client_tls_protocols
Which TLS protocol versions are allowed. Allowed values:
tlsv1.0, tlsv1.1,
tlsv1.2, tlsv1.3. Shortcuts: all
(tlsv1.0,tlsv1.1,tlsv1.2,tlsv1.3), secure (tlsv1.2,tlsv1.3),
legacy (all).
Default: all
client_tls_ciphers
Default: fast
client_tls_ecdhcurveElliptic Curve name to use for ECDH key exchanges.
Allowed values: none (DH is disabled),
auto (256-bit ECDH), curve name.
Default: auto
client_tls_dheparamsDHE key exchange type.
Allowed values: none (DH is disabled),
auto (2048-bit DH), legacy
(1024-bit DH).
Default: auto
server_tls_sslmodeTLS mode to use for connections to Postgres Pro servers. TLS connections are disabled by default.
disable
Plain TCP. TLS is not even requested from server. Default.
prefer
TLS connection is always requested first from Postgres Pro, when refused connection will be established over plain TCP. Server certificate is not validated.
require
Connection must go over TLS. If server rejects it, plain TCP is not attempted. Server certificate is not validated.
verify-ca
Connection must go over TLS and server certificate must be
valid according to server_tls_ca_file. Server host name is
not checked against certificate.
verify-full
Connection must go over TLS and server certificate must be
valid according to server_tls_ca_file. Server host name
must match certificate info.
server_tls_ca_fileRoot certificate file to validate Postgres Pro server certificates.
Default: unset.
server_tls_key_filePrivate key for pgbouncer to authenticate against Postgres Pro server.
Default: not set.
server_tls_cert_fileCertificate for private key. Postgres Pro server can validate it.
Default: not set.
server_tls_protocols
Which TLS protocol versions are allowed. Allowed values:
tlsv1.0, tlsv1.1,
tlsv1.2, tlsv1.3. Shortcuts: all
(tlsv1.0,tlsv1.1,tlsv1.2,tlsv1.3), secure (tlsv1.2,tlsv1.3),
legacy (all).
Default: all
server_tls_ciphers
Default: fast
Setting the following timeouts causes unexpected 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. [seconds]
Default: 0.0 (disabled)
query_wait_timeoutMaximum time queries are allowed to spend waiting for execution. If the query is not assigned to a server during that time, the client is disconnected. This is used to prevent unresponsive servers from grabbing up connections. [seconds]
It also helps when server is down or database rejects connections for any reason. If this is disabled, clients will be queued infinitely.
Default: 120
client_idle_timeoutClient connections idling longer than this many seconds are closed. This should be larger than the client-side connection lifetime settings, and only used for network problems. [seconds]
Default: 0.0 (disabled)
idle_transaction_timeoutIf client has been in "idle in transaction" state longer, it will be disconnected. [seconds]
Default: 0.0 (disabled)
pkt_bufInternal 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: 4096
max_packet_sizeMaximum size for Postgres Pro packets that pgbouncer allows through. One packet is either one query or one result set row. Full result set can be larger.
Default: 2147483647
listen_backlogBacklog argument for listen(2). Determines how many new unanswered connection attempts are kept in queue. When queue is full, further new connections are dropped.
Default: 128
sbuf_loopcnt
How many times to process data on one connection, before
proceeding. Without this limit, one connection with a big
result set can stall pgbouncer for a long time. One loop
processes one pkt_buf amount of data. 0 means no limit.
Default: 5
suspend_timeoutHow many seconds to wait for buffer flush during SUSPEND or reboot (-R). Connection is dropped if flush does not succeed.
Default: 10
tcp_defer_accept
For details on this and other TCP options, please see
man 7 tcp.
Default: 45 on Linux, otherwise 0
tcp_socket_bufferDefault: not set
tcp_keepaliveTurns on basic keepalive with OS defaults.
On Linux, the system defaults are tcp_keepidle=7200, tcp_keepintvl=75, tcp_keepcnt=9. They are probably similar on other operating systems.
Default: 1
tcp_keepcntDefault: not set
tcp_keepidleDefault: not set
tcp_keepintvlDefault: not set
This contains key=value pairs where key will be taken as a database name and value as a libpq connect-string style list of key=value pairs. As actual libpq is not used, not all features from libpq can be used (service=, .pgpass).
Database name can contain characters _0-9A-Za-z
without quoting. Names that contain other chars need to be quoted
with standard SQL ident quoting: double quotes where ""
is taken as single quote.
"*" acts as fallback database: if the exact name does
not exist, its value is taken as connect string for requested
database. Such automatically created database entries are cleaned
up if they stay idle longer than the time specified in
autodb_idle_timeout parameter.
dbnameDestination database name.
Default: same as client-side database name.
host
Host name or IP address to connect to. Host names are resolved
at connect time, the result is cached per dns_max_ttl parameter.
When a host name's resolution changes, existing server connections are
automatically closed when they are released (according to the pooling
mode), and new server connections immediately use the new resolution.
If DNS returns several results, they are used in round-robin
manner.
Default: not set, meaning to use a Unix socket.
portDefault: 5432
user
If user= is set, all connections to the
destination database will be done with the specified user,
meaning that there will be only one pool for this database.
Otherwise pgbouncer tries to log into the destination database with client username, meaning that there will be one pool per user.
password
The length for password is limited to 160 characters maximum.
If no password is specified here, the password from the
auth_file or auth_query will be used.
auth_user
Override of the global auth_user setting, if specified.
pool_size
Set maximum size of pools for this database. If not set, the
default_pool_size is used.
reserve_pool
Set additional connections for this database.
If not set, reserve_pool_size is used.
connect_queryQuery to be executed after a connection is established, but before allowing the connection to be used by any clients. If the query raises errors, they are logged but ignored otherwise.
pool_modeSet the pool mode specific to this database. If not set, the default pool_mode is used.
max_db_connectionsConfigure a database-wide maximum (i.e. all pools within the database will not have more than this many server connections).
client_encoding
Ask specific client_encoding from server.
datestyle
Ask specific datestyle from server.
timezone
Ask specific timezone from
server.
This contains key=value pairs where the key will be taken as a user name and the value as a libpq connect-string style list of key=value pairs of configuration settings specific for this user. Only a few settings are available here.
pool_modeSet the pool mode to be used for all connections from this user. If not set, the database or default pool_mode is used.
max_user_connectionsConfigure a maximum for the user (i.e. all pools with the user will not have more than this many server connections).
The pgbouncer config file can contain include directives, which specify another configuration file to read and process. This allows for splitting the configuration file into physically separate parts. The include directives look like this:
%include filename
If the file name is not absolute path it is taken as relative to current working directory.
pgbouncer needs its own user database. The users are loaded from a text file in following format:
"username1" "password" ... "username2" "md5abcdef012342345" ... "username2" "SCRAM-SHA-256$iterations:salt$storedkey:serverkey"
There should be at least two fields, surrounded by double quotes. The first field is the username and the second is either a plain-text, a MD5-hidden password, or a SCRAM secret. pgbouncer ignores the rest of the line.
Postgres Pro MD5-hidden password format:
"md5" + md5(password + username)
So user admin with password 1234 will have MD5-hidden password
md545f2603610af569b6155c45067268c6b.
Postgres Pro SCRAM secret format:
SCRAM-SHA-256$iterations:salt$storedkey:serverkey
The authentication file can be written by hand, but it's also useful
to generate it from some other list of users and passwords. See
./etc/mkauth.py for a sample script to generate the authentication
file from the pg_shadow system table.
It follows the format of Postgres Pro pg_hba.conf file described in Section 19.1.
Supported record types: local, host, hostssl, hostnossl.
Database field: Supports all, sameuser,
@file, multiple names.
Not supported: replication, samerole, samegroup.
Username field: Supports all, @file, multiple names. Not
supported: +groupname.
Address field: Supported IPv4, IPv6.
Not supported: DNS names,
domain prefixes.
Auth-method field: Only methods supported by
pgbouncer's auth_type
are supported, except any and pam,
which only work globally. Username map (map=) parameter
is not supported.
Minimal config:
[databases] template1 = host=127.0.0.1 dbname=template1 auth_user=someuser [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 ; access to destination database will go with single user forcedb = host=127.0.0.1 port=300 user=baz password=foo client_encoding=UNICODE datestyle=ISO
Example of a secure function for auth_query:
CREATE OR REPLACE FUNCTION pgbouncer.user_lookup(in i_username text, out uname text, out phash text)
RETURNS record AS $$
BEGIN
SELECT usename, passwd FROM pg_catalog.pg_shadow
WHERE usename = i_username INTO uname, phash;
RETURN;
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;
REVOKE ALL ON FUNCTION pgbouncer.user_lookup(text) FROM public, pgbouncer;
GRANT EXECUTE ON FUNCTION pgbouncer.user_lookup(text) TO pgbouncer;