cr_conn_unknow_protocol
Moderate
MySQL · Connector / Client Library
MySQL client error 2047: CONN UNKNOW PROTOCOL.
Quick Answer
Error code CR_CONN_UNKNOW_PROTOCOL on your MySQL Connector / Client Library means: MySQL client error 2047: CONN UNKNOW PROTOCOL.. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Capture client and server logs for CR_CONN_UNKNOW_PROTOCOL, including host, port, TLS mode, and statement context.
2
Verify firewall/proxy/network rules and regional endpoint targeting for the workload.
3
Capture endpoint, DNS resolution, TLS handshake, and socket metrics at failure time.
4
Retry with bounded exponential backoff and idempotency protection where possible.
5
Track CR_CONN_UNKNOW_PROTOCOL frequency by environment to detect regressions early.
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
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