20.4 NDB Cluster Advisors

This section describes the expression-based Cluster Advisors.

• Cluster Data Node Redo Buffer Space Getting Low

• Cluster Data Node Redo Log Space Getting Low

• Cluster Data Node Undo Buffer Space Getting Low

• Cluster Data Node Undo Log Space Getting Low

• Cluster DiskPageBuffer Hit Ratio Is Low

Cluster Data Node Redo Buffer Space Getting Low

Advises when the redo buffers start to fill up.

Default frequency 00:05:00

Default auto-close enabled no

Cluster Data Node Redo Log Space Getting Low

Advises when the redo log spaces start to fill up.

Default frequency 00:05:00

Default auto-close enabled no

Cluster Data Node Undo Buffer Space Getting Low

Advises when the undo buffers start to fill up.

Default frequency 00:05:00

Default auto-close enabled no

Cluster Data Node Undo Log Space Getting Low

Advises when the undo log spaces start to fill up.

Default frequency 00:05:00

Default auto-close enabled no

Cluster DiskPageBuffer Hit Ratio Is Low

Advises when the hit-rate for the DiskPageBuffer falls below a threshold. May happen temporarily after restarting one or more data nodes. This is the average ratio since the last sample period.

For more information on DiskPageBuffer, see The ndbinfo diskpagebuffer Table.

Default frequency 00:05:00

Default auto-close enabled no