Skip to main content

ProxySQL Error Codes

ProxySQL uses the following custom error codes:

ErrorMessage
9001Max connect timeout reached while reaching hostgroup %d after %llums
9002Max connect failure while reaching hostgroup %d
9003Command not supported
9004Backend Offline Detected
9006Connection is locked to hostgroup X but trying to reach hostgroup Y

Error Descriptions

Error 9001 — Indicates a connection timeout when attempting to reach a specified hostgroup.

Error 9002 — Signals that the maximum number of connection failures to a hostgroup has been exceeded.

Error 9003 — Returned when ProxySQL receives an unsupported command (e.g., INSERT VALUES via the ClickHouse interface).

Error 9004 — ProxySQL identified a backend server as unavailable before attempting to use a connection. The proxy detected the issue through monitoring mechanisms rather than a failed connection attempt.

Error 9006 — Occurs when a connection bound to one hostgroup attempts to access a different hostgroup.