PostgreSQL: application_name connection parameter is unrecognized

Summary

ProxySQL PostgreSQL appears not to recognize the standard PostgreSQL application_name connection parameter. When a client connects with application_name configured, ProxySQL logs warnings about an unrecognized connection parameter and unknown connection options.

This also appears to trigger hostgroup locking, potentially affecting connection multiplexing and routing behavior.

Environment

• ProxySQL version: 3.0.11
• Database: PostgreSQL 17

Observed behavior

When a client connects with application_name=an_applicatiton_name, ProxySQL logs the following warnings:

2026-10-16 09:26:00 PgSQL_Protocol.cpp:1313:process_handshake_response_packet(): [WARNING] Unrecognized connection parameter. Please report this as a bug for future enhancements:application_name:<APPLICATION_NAME>

2026-10-16 09:26:00 PgSQL_Session.cpp:5166:handler___status_WAITING_CLIENT_DATA___STATE_SLEEP___PGSQL_QUERY_qpo(): [WARNING] Unknown connection options from client 192.168.0.61:56176. Setting lock_hostgroup. Please report a bug for future enhancements:-c application_name=<APPLICATION_NAME>

These warnings recur for multiple client connections.

Expected behavior

ProxySQL should recognize and handle the standard PostgreSQL application_name connection parameter without treating