PgBouncer

PgBouncer is made available on Bridge instances by default to ease connection management by multiplexing native Postgres connections across its own "virtual" connections.

Although the PgBouncer service is available on Bridge instances by default, you'll need to take one extra step on each database you want to use it on by installing the crunchy_pooler extension.

Activating PgBouncer with the crunchy_pooler extension

As the superuser, run this in the database to install the crunchy_pooler extension:

CREATE EXTENSION crunchy_pooler;

crunchy_pooler is simple extension which creates a user called crunchy_pooler with access to a single function called user_lookup that allows PgBouncer to authenticate incoming connections. Now when a client makes a connection to PgBouncer, it can check whether its credentials are valid by querying Postgres' canonical user store.

Info

The crunchy_pooler extension must be installed in each database where you want to connect to PgBouncer. Otherwise you may receive an error like:

failed: FATAL: bouncer config error

Connect to the database and run: create extension crunchy_pooler; to resolve the error.

Connecting to PgBouncer

Clients will connect to PgBouncer using the same connection string they'd use for the main Postgres database, except on port 5431 instead of the usual 5432:

psql postgres://my_application_user:my_application_passwo[email protected]:5431/mydb

You can connect to PgBouncer using the application role, any individual user role created for team members, or any custom user roles that you may have created (for example, using the CREATE ROLE SQL command). The user_lookup function created by crunchy_pooler will deny lookups on superusers and replication roles -- only roles without superuser or replication privileges will be able to connect through PgBouncer. See User Management for more about Postgres users and roles on Crunchy Bridge.

Hint

The terms "user" and "role" in Postgres are largely synonymous, with a minor difference being that CREATE USER (versus CREATE ROLE) implies LOGIN privilege, so according to the principle of least privilege, CREATE ROLE is the better choice for users/roles that meant for use by applications rather than people.

Disabling PgBouncer

Dropping the crunchy_pooler exception will functionally disable PgBouncer as it'll no longer be able to authenticate:

DROP EXTENSION crunchy_pooler;