3303
MySQLERRORNotableReplicationHIGH confidence
Replication connection timed out
Production Risk
Medium — replication stops; the replica reconnects automatically if configured.
How to reproduce
trigger — this will error
trigger — this will error
CHANGE REPLICATION SOURCE TO SOURCE_HEARTBEAT_PERIOD = 30;
expected output
ERROR 3303 (HY000): The replica I/O thread stopped because the connection timeout interval was reached.
Fix
Increase the timeout
Increase the timeout
SET GLOBAL replica_net_timeout = 120;
Why this works
Gives the source more time to respond before the I/O thread declares the connection dead.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 3303 ER_REPLICA_TIMEOUT
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