PgBouncer Administration Console.

Synopsis

psql -p <port> pgbouncer

Description

The PgBouncer Administration Console is available via psql. Connect to the PgBouncer <port> and the virtual database named pgbouncer to log in to the console.

Users listed in the pgbouncer.ini configuration parameters admin_users and stats_users have privileges to log in to the PgBouncer Administration Console. When auth_type=any, then any user is allowed in as a stats_user.

Additionally, the user name pgbouncer is allowed to log in without password when the login comes via the Unix socket and the client has same Unix user UID as the running process.

You can control connections between PgBouncer and Greenplum Database from the console. You can also set PgBouncer configuration parameters.

Options

-p <port>

The PgBouncer port number.

Command Syntax

pgbouncer=# SHOW help;
NOTICE:  Console usage
DETAIL:  
    SHOW HELP|CONFIG|USERS|DATABASES|POOLS|CLIENTS|SERVERS|VERSION
    SHOW FDS|SOCKETS|ACTIVE_SOCKETS|LISTS|MEM
    SHOW DNS_HOSTS|DNS_ZONES
    SHOW STATS|STATS_TOTALS|STATS_AVERAGES
    SHOW TOTALS
    SET key = arg
    RELOAD
    PAUSE [<db>]
    RESUME [<db>]
    DISABLE <db>
    ENABLE <db>
    RECONNECT [<db>]
    KILL <db>
    SUSPEND
    SHUTDOWN

Administration Commands

The following PgBouncer administration commands control the running pgbouncer process.

PAUSE [<db>]

If no database is specified, PgBouncer tries to disconnect from all servers, first waiting for all queries to complete. The command will not return before all queries are finished. This command is to be used to prepare to restart the database.

If a database name is specified, PgBouncer pauses only that database.

New client connections to a paused database will wait until a RESUME command is invoked.

DISABLE <db>

Reject all new client connections on the database.

ENABLE <db>

Allow new client connections after a previous DISABLE command.

RECONNECT

Close 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.

KILL <db>

Immediately drop all client and server connections to the named database.

New client connections to a killed database will wait until RESUME is called.

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 when rebooting PgBouncer online.

New client connections to a suspended database will wait until RESUME is called.

RESUME [<db>]

Resume work from a previous KILL, PAUSE, or SUSPEND command.

SHUTDOWN

The PgBouncer process will exit. To exit from the psql command line session, enter \q.

RELOAD

The PgBouncer process reloads the current configuration file and updates the 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

WAIT_CLOSE [<db>]

Wait until all server connections, either of the specified database or of all databases, have cleared the “close_needed” state (see 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.

SET key = value

Changes the specified configuration setting. See the SHOW CONFIG; command.

(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 PostgreSQL backend like any other SQL command.)

SHOW Command

The SHOW <category> command displays different types of PgBouncer information. You can specify one of the following categories:

• CLIENTS
• CONFIG
• DATABASES
• DNS_HOSTS
• DNS_ZONES
• FDS
• LISTS
• MEM
• POOLS
• SERVERS
• SOCKETS, ACTIVE_SOCKETS,
• STATS
• STATS_TOTALS
• STATS_AVERAGES
• TOTALS
• USERS
• VERSION

CLIENTS

CONFIG

Show the current PgBouncer configuration settings, one per row, with the following columns:

DATABASES

DNS_HOSTS

Show host names in DNS cache.

DNS_ZONES

Show DNS zones in cache.

FDS

SHOW FDS is an internal command used for an online restart, for example when upgrading to a new PgBouncer version. It displays a list of file descriptors in use with the internal state attached to them. This command blocks the internal event loop, so it should not be used while PgBouncer is in use.

When the connected user has username “pgbouncer”, connects through a Unix socket, and has the same UID as the running process, the actual file descriptors are passed over the connection. This mechanism is used to do an online restart.

LISTS

Shows the following PgBouncer internal information, in columns (not rows):

MEM

Shows low-level information about the current sizes of various internal memory allocations. The information presented is subject to change.

POOLS

A new pool entry is made for each pair of (database, user).

SERVERS

SOCKETS, ACTIVE_SOCKETS

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.

STATS

Shows statistics. In this and related commands, the total figures are since process start, the averages are updated every stats_period.

STATS_AVERAGES

Subset of SHOW STATS showing the average values for selected statistics (avg_)

STATS_TOTALS

Subset of SHOW STATS showing the total values for selected statistics (total_)

TOTALS

Like SHOW STATS but aggregated across all databases.

USERS

VERSION

Display PgBouncer version information.

<div class=”note>Note: This reference documentation is based on the PgBouncer 1.16 documentation.

Signals

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.

Libevent Settings

From the Libevent documentation:

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, pgbouncer.ini