The configuration file is in "ini" format. Section names are between "[" and "]". Lines starting with ";" or "#" are taken as comments and ignored. The characters ";" and "#" are not recognized as special when they appear later in the line.
Specifies the log file. For daemonization (-d), either this or syslog need to be set.
The log file is kept open, so after rotation, kill -HUP or on console RELOAD; should be done. On Windows, the service must be stopped and started.
Note that setting logfile does not by itself turn off logging to stderr. Use the command-line option -q or -d for that.
Default: not set
Specifies the PID file. Without pidfile set, daemonization (-d) is not allowed.
Default: not set
Specifies a list (comma-separated) 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 accepted.
Addresses can be specified numerically (IPv4/IPv6) or by name.
Default: not set
Which port to listen on. Applies to both TCP and Unix sockets.
Default: 6432
Specifies the location for Unix sockets. Applies to both the listening socket and to server connections. If set to an empty string, Unix sockets are disabled. A value that starts with @ specifies that a Unix socket in the abstract namespace should be created (currently supported on Linux and Windows).
For online reboot (-R) to work, a Unix socket needs to be configured, and it needs to be in the file-system namespace.
Default: /tmp (empty on Windows)
File system mode for Unix socket. Ignored for sockets in the abstract namespace. Not supported on Windows
Default: 0777
Group name to use for Unix socket. Ignored for sockets in the abstract namespace. Not supported on Windows
Default: not set
If 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 the given user. Not supported on Windows
Default: not set
Specifies 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. Transactions spanning multiple statements are disallowed in this mode.
Maximum number of client connections allowed.
Default: 100
How many server connections to allow per user/database pair. Can be overridden in the per-database configuration
Default: 20
Add more server connections to pool if below this number. Improves behavior when the normal load suddenly comes back after a period of total inactivity. The value is effectively capped at the pool size.
Default: 0 (disabled)
How many additional connections to allow to a pool (see reserve_pool_timeout). 0 disables.
Default: 0 (disabled)
If a client has not been serviced in this time, use additional connections from the reserve pool. 0 disables. [seconds]
Default: 5.0
Do not allow more than this many server connections per database (regardless of user). This considers the PgBouncer database that the client has connected to, not the PostgreSQL database of the outgoing connection
Default: 0 (unlimited)
Do not allow more than this many server connections per user (regardless of database). This considers the PgBouncer user that is associated with a pool, which is either the user specified for the server connection or in absence of that the user the client has connected as.
Default: 0 (unlimited)
By 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 a round-robin system behind a database address (TCP, DNS, or host list), then it is better if PgBouncer also uses connections in that manner, thus achieving uniform load.
Default: 0
By default, PgBouncer tracks client_encoding, datestyle, timezone, standard_conforming_strings and application_name parameters per client. To allow other parameters to be tracked, they can be specified here, so that PgBouncer knows that they should be maintained in the client variable cache and restored in the server whenever the client becomes active.
If you need to specify multiple values, use a comma-separated list (e.g. default_transaction_readonly, IntervalStyle)
Default: IntervalStyle
By default, PgBouncer allows only parameters it can keep track of in startup packets: client_encoding, datestyle, timezone and standard_conforming_strings. All others parameters will raise an error. To allow others parameters, they can be specified here, so that PgBouncer knows that they are handled by the admin and it can ignore them.
If you need to specify multiple values, use a comma-separated list (e.g. options,extra_float_digits)
Default: empty
The peer id used to identify this PgBouncer process in a group of PgBouncer processes that are peered together. The peer_id value should be unique within a group of peered PgBouncer processes. When set to 0 pgbouncer peering is disabled. See the docs for the [peers] section for more information. The maximum value that can be used for the peer_id is 16383.
Default: 0
Disable the Simple Query protocol (PQexec). Unlike the 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 the Extended Query protocol will stay working.
Default: 0
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 at the start of a connection. If application_name is later changed with SET, PgBouncer does not change it again.
Default: 0
Show location of current config file. Changing it will make PgBouncer use another config file for next RELOAD / SIGHUP
Default: file from command line
Used on win32 service registration
Default: pgbouncer
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
When this is set to a non-zero value PgBouncer tracks protocol-level named prepared statements related commands sent by the client in transaction and statement pooling mode. PgBouncer makes sure that any statement prepared by a client is available on the backing server connection. Even when the statement was originally prepared on another server connection.
PgBouncer internally examines all the queries that are sent as a prepared statement by clients and gives each unique query string an internal name with the format PGBOUNCER_{unique_id}. Prepared statements are only prepared using this name on the corresponding PostgreSQL server. PgBouncer keeps track of the name that the client gave to each prepared statement. It rewrites each command that uses a prepared statement to use the matching internal name (e.g. PGBOUNCER_123) before forwarding that command to the server. More importantly, if the prepared statement that the client wants to use is not prepared on the server yet, it automatically prepares that statement before forwarding the command that the client sent.
Note: This tracking and rewriting of prepared statement commands does not work for SQL-level prepared statement commands such as PREPARE, EXECUTE, DEALLOCATE, DEALLOCATE ALL and DISCARD ALL. Running DEALLOCATE ALL and DISCARD ALL is especially problematic, since those commands appear to run successfully, but they mess up with the state of the server connection significantly without PgBouncer noticing. Which in turn will very likely break the execution of any further prepared statements on that server connection.
The actual value of this setting controls the number of prepared statements kept active on a single server connection. When the setting is set to 0 prepared statement support for transaction and statement pooling is disabled. To get the best performance you should try to make sure that this setting is larger than the amount of commonly used prepared statements in your application. Keep in mind that the higher this value, the larger the memory footprint of each PgBouncer connection will be on your PostgreSQL server, because it will keep more queries prepared on those connections. It also increases the memory footprint of PgBouncer itself, because it now needs to keep track of query strings.
Default: 0
PgBouncer handles its own client authentication and has its own database of users. These settings control this.
How to authenticate users.
cert: Client must connect over TLS connection with a valid client certificate. The user name is then taken from the CommonName field from the certificate.
md5: Use MD5-based password check. This is the default authentication method. auth_file may contain both MD5-encrypted and 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.
plain: The clear-text password is sent over the wire. Deprecated.
trust: No authentication is done. The user name must still exist in auth_file.
any: Like the trust method, but the user name given is ignored. Requires that all databases are configured to log in as a specific user. Additionally, the console database allows any user to log in as admin.
hba: The actual authentication type is loaded from auth_hba_file. This allows different authentication methods for different access paths, for example: connections over Unix socket use the peer auth method, connections over TCP must use TLS.
pam: PAM is used to authenticate users, auth_file is ignored. This method is not compatible with databases using the auth_user option. The service name reported to PAM is “pgbouncer”. pam is not supported in the HBA configuration file.
HBA configuration file to use when auth_type is hba.
The name of the file to load user names and passwords from
Most authentication types (see above) require that either auth_file or auth_user be set; otherwise there would be no users defined.
If auth_user is set, then any user not specified in auth_file will be queried through the auth_query query from pg_shadow in the database, using auth_user. The password of auth_user will be taken from auth_file. (If the auth_user does not require a password then it does not need to be defined in auth_file.)
Direct access to pg_shadow requires admin rights. It’s preferable to use a non-superuser that calls a SECURITY DEFINER function instead.
Query to load user’s password from database.
Direct access to pg_shadow requires admin rights. It’s preferable to use a non-superuser that calls a SECURITY DEFINER function instead.
Note that the query is run inside the 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
Database name in the [database] section to be used for authentication purposes. This option can be either global or overridden in the connection string if this parameter is specified.
Comma-separated list of database users that are allowed to connect and run all commands on the console. Ignored when auth_type is any, in which case any user name is allowed in as admin.
Comma-separated list of database users that are allowed to connect and run read-only queries on the console. That means all SHOW commands except SHOW FDS.
Query sent to server on connection release, before making it available to other clients. At that moment no transaction is in progress, so the value should not include ABORT or ROLLBACK
The query is supposed to clean any changes made to the database session so that the next client gets the connection in a well-defined state. The default is DISCARD ALL, which cleans everything, but that leaves the next client no pre-cached state. It can be made lighter, e.g. DEALLOCATE ALL to just drop prepared statements, if the application does not break when some state is kept around.
When transaction pooling is used, the server_reset_query is not used, because in that mode, clients must not use any session-based features, since each transaction ends up in a different connection and thus gets a different session state.
Default: DISCARD ALL
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 a reset query.
This setting is for working around broken setups that run applications that use session features over a transaction-pooled PgBouncer. It changes non-deterministic breakage to deterministic breakage: Clients always lose their state after each transaction.
Default: 0
How long to keep released connections available for immediate re-use, without running server_check_query on it. If 0 then the check is always run
Default: 30
Simple do-nothing query to check if the server connection is alive
If an empty string, then sanity checking is disabled
Default: select 1
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
The pooler will close an unused (not currently linked to any client connection) 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
If a server connection has been idle more than this many seconds it will be closed. If 0 then this timeout is disabled. [seconds]
Default: 600.0
If connection and login don’t finish in this amount of time, the connection will be closed. [seconds]
Default: 15
If login to the server failed, because of failure to connect or from authentication, the pooler waits this much before retrying to connect. During the waiting interval, new clients trying to connect to the failing server will get an error immediately without another connection attempt. [seconds]
The purpose of this behavior is that clients don’t unnecessarily queue up waiting for a server connection to become available if the server is not working. However, it also means that if a server is momentarily failing, for example during a restart or if the configuration was erroneous, then it will take at least this long until the pooler will consider connecting to it again. Planned events such as restarts should normally be managed using the PAUSE command to avoid this
Default: 15
If a client connects but does not manage to log in 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
If 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
How long DNS lookups can be cached. The actual DNS TTL is ignored. [seconds]
Default: 15
How long DNS errors and NXDOMAIN DNS lookups can be cached. [seconds]
Default: 15
Period to check if a zone serial has changed
Default: 0.0 (disabled)
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 the key and certificate 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 the client presents a client certificate, it is not validated
prefer: Same as allow
require: Client must use TLS. If not, the client connection is rejected. If the client presents a client certificate, it is not validated.
verify-ca: Client must use TLS with valid client certificate
verify-full: Same as verify-ca
Private key for PgBouncer to accept client connections.
Certificate for private key. Clients can validate it.
Root certificate file to validate client certificates.
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: secure
Allowed TLS ciphers, in OpenSSL syntax. Shortcuts:
- default/secure/fast/normal (these all use system wide OpenSSL defaults)
- all (enables all ciphers, not recommended)
Only connections using TLS version 1.2 and lower are affected. There is currently no setting that controls the cipher choices used by TLS version 1.3 connections.
Default: default
TLS mode to use for connections to PostgreSQL servers. The default mode is prefer
disable: Plain TCP. TLS is not even requested from the server.
allow: FIXME: if server rejects plain, try TLS?
prefer: TLS connection is always requested first from PostgreSQL. If refused, the connection will be established over plain TCP. Server certificate is not validated. Default
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 information.
Root certificate file to validate PostgreSQL server certificates.
Private key for PgBouncer to authenticate against PostgreSQL server.
Certificate for private key. PostgreSQL server can validate it.
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: secure
Allowed TLS ciphers, in OpenSSL syntax. Shortcuts:
- default/secure/fast/normal (these all use system wide OpenSSL defaults)
- all (enables all ciphers, not recommended)
Only connections using TLS version 1.2 and lower are affected. There is currently no setting that controls the cipher choices used by TLS version 1.3 connections.
Default: default
The section [databases] defines the names of the databases that clients of PgBouncer can connect to and specifies where those connections will be routed. The section contains key=value lines like
dbname = connection string
where the key will be taken as a database name and the value as a connection string, consisting of key=value pairs of connection parameters, described below (similar to libpq, but the actual libpq is not used and the set of available features is different). Example:
foodb = host=host1.example.com port=5432
bardb = host=localhost dbname=bazdb
The database name can contain characters _0-9A-Za-z without quoting. Names that contain other characters need to be quoted with standard SQL identifier quoting: double quotes, with “” for a single instance of a double quote.
The database name “pgbouncer” is reserved for the admin console and cannot be used as a key here.
"*" acts as a fallback database: If the exact name does not exist, its value is taken as connection string for the requested database. For example, if there is an entry (and no other overriding entries)
* = host=foo
then a connection to PgBouncer specifying a database “bar” will effectively behave as if an entry
bar = host=foo dbname=bar
exists (taking advantage of the default for dbname being the client-side database name; see below).
Such automatically created database entries are cleaned up if they stay idle longer than the time specified by the autodb_idle_timeout parameter.
Destination database name
Default: same as client-side database name
Host name or IP address to connect to. Host names are resolved at connection 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 a round-robin manner.
If the value begins with /, then a Unix socket in the file-system namespace is used. If the value begins with @, then a Unix socket in the abstract namespace is used.
A comma-separated list of host names or addresses can be specified. In that case, connections are made in a round-robin manner. (If a host list contains host names that in turn resolve via DNS to multiple addresses, the round-robin systems operate independently. This is an implementation dependency that is subject to change.) Note that in a list, all hosts must be available at all times: There are no mechanisms to skip unreachable hosts or to select only available hosts from a list or similar. (This is different from what a host list in libpq means.) Also note that this only affects how the destinations of new connections are chosen. See also the setting server_round_robin for how clients are assigned to already established server connections.
Examples:
host=localhost
host=127.0.0.1
host=2001:0db8:85a3:0000:0000:8a2e:0370:7334
host=/var/run/postgresql
host=192.168.0.1,192.168.0.2,192.168.0.3
Default: 5432
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 logs into the destination database with the client user name, meaning that there will be one pool per user.
If no password is specified here, the password from the auth_file or auth_query will be used.
Override of the global auth_user setting, if specified
Set the maximum size of pools for this database. If not set, the default_pool_size is used
Set the minimum pool size for this database. If not set, the global min_pool_size is used
Set additional connections for this database. If not set, reserve_pool_size is used
Query 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
Set the pool mode specific to this database. If not set, the default pool_mode is used
Configure a database-wide maximum (i.e. all pools within the database will not have more than this many server connections)
Ask specific client_encoding from server
Ask specific datestyle from server
Ask specific timezone from server