eG Monitoring
 

Measures reported by MySqlCluQCacheTest

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

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

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Queries_registered Indicates the number of queries that are registered with the cache of this node. Number  
Queries_added Indicates the number of queries added to the cache of this node during the last measurement period. Number  
Cache_hits Indicates the number of times the cache of this node was accessed during the last measurement period. Number  
Queries_deleted 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.
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
Free_memory 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.
Free_blocks Indicates the current number of free memory blocks in the query cache of this node. Number  
Total_blocks Indicates the total number of blocks in the query cache of this node. Number  
Total_queries 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.