PgBouncer

Learn about configurations >

• listen_port | int

  Default: 6432

  The port on which pgbouncer listens for traffic. Corresponds to listen_port in pgbouncer config.

• max_db_connections | int

  Default: 100

  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.

  Note 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.

  This is used to calculate the following pgbouncer.ini config options, which are documented in the pgbouncer config docs here: https://www.pgbouncer.org/config.html.

  • Firstly, the number of pgbouncer instances is calculated based on the number of CPU cores in the current deployment.
  • effective DB connections = max_db_connections / pgbouncer instances
  • default_pool_size = effective connections / 2
  • min_pool_size = effective connections / 4
  • reserve_pool_size = effective connections / 4

  If max_db_connections is set to 0, the derivatives are set thusly, based on pgbouncer defaults:

  • default_pool_size = 20
  • min_pool_size = 10
  • reserve_pool_size = 10

  0 = unlimited.

• metrics_port | int

  Default: 9127

  The port on which the pgbouncer prometheus exporter serves metrics.

• pool_mode | string

  Default: session

  Specifies when a server connection can be reused by other clients. Can be one of the following values:

  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.

• vip | string

  Virtual IP to use to front pgbouncer units. Used only in case of external node connection.