When the request to a Peer (upstream server) is finished, the connection to that peer is kept alive and added to a connection pool to be reused by subsequent requests. This happens automatically without any special configuration.
Requests that reuse previously established connections avoid the latency and compute cost of setting up a new connection, improving the Pingora server's overall performance and scalability.
Only the connections to the exact same Peer can be reused by a request. For correctness and security reasons, two Peers are the same if and only if all the following attributes are the same
- IP:port
- scheme
- SNI
- client cert
- verify cert
- verify hostname
- alternative_cn
- proxy settings
To disable connection pooling and reuse to a certain Peer, just set the idle_timeout to 0 seconds to all requests using that Peer.
A connection is considered not reusable if errors happen during the request.