My Oracle Support Banner

"Disconnecting lagging nodes"; "Disconnecting node N because it has exceeded MaxBufferedEpochs (100 >= 100), epoch N/N" (Doc ID 2985376.1)

Last updated on MAY 13, 2024

Applies to:

MySQL NDB Cluster - Version 8.0 and later
Information in this document applies to any platform.

Symptoms

An SQL node is occasionally  disconnected from data nodes with messages in the cluster log like below:

 When an SQL node is disconnected from the cluster, the LOST_EVENTS event is generated as described in <Document 1024297.1>.

Cause

To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!


In this Document
Symptoms
Cause
Solution
 Use fast network
 Keep transactions small
 Do not enable binary logging for NDB on too many SQL nodes
 Use dedicated SQL nodes
 Increase MaxBufferedEpochs, and MaxBufferedEpochBytes
References


My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.