MySQL Cluster Queue Cache Test

This test monitors the health of the query cache in the MySQL cluster server.

Target of the test : A MySQL Cluster

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each node in the target MySQL Cluster database server being monitored

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The host for which the test is to be configured.

Port

The port at which the specified host listens.

Database

Specify the name of a database on the target MySQL Cluster database server being monitored

Username and Password

The eG agent has to be configured with the credentials of a user who has server-wide Process and Select privileges on the monitored MySQL Cluster database server. To know how to create such a user, refer to Pre-requisites for Monitoring the MySQL Cluster Database Server topic.

Confirm Password

Confirm the password by retyping it here.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Cache hits

Indicates the number of times the cache of this node was accessed during the last measurement period.

Number

 

Free blocks in cache

Indicates the current number of free memory blocks in the query cache of this node.

Number

 

Free memory in cache

Indicates the amount of free memory available in the query cache of this node.

MB

A low value of this measure could cause subsequent queries to be rejected by the cache, owing to low memory availability. It would be good practice to tune the cache memory to handle more load.

Non-cached queries

Indicates the number of queries that were not cached by the cache of this node during the last measurement period.

Number

The queries are not cacheable due to their QUERY_CACHE_TYPE.

Queries added to cache

Indicates the number of queries added to the cache of this node during the last measurement period.

Number

 

Queries deleted from cache

Indicates the number of queries that were deleted from the cache of this node during the last measurement period.

Number

A high value could indicate low memory allocation for the query cache. Since reading from the cache is less expensive than reading directly from the database, a higher memory allocation to the cache is advisable.

Queries registered in cache

Indicates the number of queries that are registered with the cache of this node.

Number

 

Blocks in cache

Indicates the total number of blocks in the query cache of this node.

Number

 

Queries in cache

Indicates the total number of queries raised the cache of this node during the last measurement period.

Number

The value of this measure is the sum of cache inserts, cache hits, and non-cached queries.