EC
2001
MySQLERRORCommonReplicationHIGH confidence

Network read error from master during replication

Production Risk

Critical — replication halts; replica data becomes stale.

What this means

The replica experienced a network read error while receiving binary log events from the source server. Replication will stop and must be restarted after the network issue is resolved.

Why it happens
  1. 1Network instability or packet loss between source and replica.
  2. 2Source server restarted or crashed mid-event stream.
  3. 3Firewall or load balancer dropping long-lived TCP connections.
  4. 4replica_net_timeout too short for the network latency.
How to reproduce
trigger — this will error
trigger — this will error
-- Observed in SHOW SLAVE STATUS output, not triggered by SQL

expected output

Error 'Got a packet bigger than max_allowed_packet bytes' on query.

Fix 1

Increase replica_net_timeout to tolerate transient network delays

Increase replica_net_timeout to tolerate transient network delays
SET GLOBAL replica_net_timeout = 120;

Why this works

A longer timeout prevents premature disconnection during brief network hiccups.

Fix 2

Restart replication after resolving the network issue

Restart replication after resolving the network issue
START SLAVE;

Why this works

Once the network is stable, replication resumes from the last committed position.

What not to do

✕

Sources
Official documentation ↗

MySQL 8.0 — 2001 ER_MASTER_NET_READ

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