1396
MariaDBerrorreplicationhigh confidence
Operation not allowed on slave
Production Risk
Low — write blocked; the protection is intentional.
What this means
A write operation (INSERT, UPDATE, DELETE, DDL) was attempted on a read-only replica server.
Why it happens
- 1read_only = ON on the replica
- 2super_read_only = ON on the replica (blocks even SUPER users)
- 3Application mistakenly targeting a replica instead of the primary
How to reproduce
trigger — this will error
trigger — this will error
INSERT INTO t (col) VALUES (1); -- on a replica with read_only=ON
expected output
ERROR 1396 (HY000): The MySQL server is running with the --read-only option so it cannot execute this statement
Fix 1
Direct writes to the primary
Why this works
Ensure the application connection string points to the primary/source server.
Fix 2
Temporarily disable read_only (DBA only)
Temporarily disable read_only (DBA only)
SET GLOBAL read_only = OFF;
Why this works
For emergency manual operations only; re-enable immediately after.
What not to do
✕
Version notes
Sources
Official documentation ↗
MySQL 8.0 — 1290 / 1396 read_only enforcement
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