Troubleshooting

Common problems with the PgBouncer pooler, what causes them and how to fix them.

Queries fail right after launch

Cause: the example databases still point at 127.0.0.1:15432, the temporary backend that exists only while the walkthrough runs.

Fix: point them at your database, see Point PgBouncer at your database, then reload PgBouncer.

Connections without TLS are refused

Cause: PgBouncer requires TLS from every client. A client using sslmode=disable is rejected.

Fix: use sslmode=verify-full with sslrootcert=/usr/local/share/sushi/pgbouncer/ca.pem, or at least sslmode=require.

Password authentication fails

Cause: the password does not match /etc/pgbouncer/userlist.txt, or your database does not accept the same user name and password.

Fix: check the client password against the user list, and make sure the same role and password exist on your database, see Users and passwords. Reload PgBouncer after editing the user list.

The backend refuses the connection

Cause: PgBouncer connects to your database with TLS required. A server without TLS, or a security group that blocks the instance, refuses it.

Fix: enable TLS on your PostgreSQL server (Amazon RDS supports it), and allow the instance in the database's security group.

SET values or prepared statements leak or disappear

Cause: the app database uses transaction pooling, so session state is not tied to one client.

Fix: connect to the session database, or change pool_mode for that entry, see Pool modes and sizes.

Clients wait for a connection

Cause: the pool is full. By default each database and user pair gets two server connections.

Fix: raise default_pool_size, and max_client_conn if needed, within your database's connection limit. Check SHOW POOLS in the admin console.

Certificate verification fails from another host

Cause: the server certificate created on first boot covers only localhost and 127.0.0.1.

Fix: issue a certificate that includes the address clients use, see Reach PgBouncer from your VPC.

PgBouncer does not start after first boot

Fix: read the first-boot log, correct the cause, and retry:

sudo journalctl -u sushi-pgbouncer-firstboot --no-pager
sudo systemctl restart sushi-pgbouncer-firstboot
sudo systemctl start pgbouncer

If it still fails, contact info@softwaresushi.com.