1797
MariaDBERRORNotableReplicationHIGH confidence
MTS: event size exceeds slave_pending_jobs_size_max
Production Risk
High — replication halted.
What this means
A single binlog event is larger than the slave_pending_jobs_size_max setting, preventing the MTS worker from queuing it.
Why it happens
- 1A very large transaction or BLOB write was replicated.
- 2slave_pending_jobs_size_max set too low for the workload.
How to reproduce
trigger — this will error
trigger — this will error
-- Large BLOB INSERT replicated to a slave with low slave_pending_jobs_size_max
expected output
ERROR 1797 (HY000): Multi-threaded slave: Slave worker has stopped after at least one previous worker encountered an error when slave-pending-jobs-size-max was exceeded.
Fix 1
Increase slave_pending_jobs_size_max
Increase slave_pending_jobs_size_max
SET GLOBAL slave_pending_jobs_size_max = 134217728; -- 128 MB
Why this works
Allows larger events to be queued for MTS workers.
Fix 2
Reduce transaction or BLOB sizes on the primary
Reduce transaction or BLOB sizes on the primary
-- Split large transactions into smaller batches
Why this works
Keeps individual events within the MTS queuing size limit.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 1797 ER_MTS_EVENT_BIGGER_PENDING_JOBS_SIZE_MAX
Content generated with AI assistance and reviewed for accuracy. Found an error? hello@errcodes.dev