eG Monitoring
 

Measures reported by IgniteCaOfHeTest

Off-heap cache refers to the logical expandable area in the memory where cached data is stored. By default, Ignite off-heap cache can occupy up to 20% of the node memory. The administrator can manually configure the storage required by the cached data in the memory.

Off-heap cache refers to the logical expandable area in the memory where cached data is stored. By default, Ignite off-heap cache can occupy up to 20% of the node memory. The administrator can manually configure the storage required by the cached data in the memory.

This test monitors the off heap cache and provides valuable insights to administrators about the performance of cache.

Outputs of the test: One set of results for each Apache Ignite Server

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
offHeapAllocatedSize Indicates the total size of memory allocated in off-heap memory. MB

The number needs to be optimal. The off-heap cache size should be allocated keeping in mind to leave some RAM on the node for other purpose.
offHeapBackupEntries Indicates the total number of cache entries stored in off-heap memory which are backup. Number

If there is a very large number of backup entries in off-heap cache means that off-heap is being used primarily for backup purpose, so even if there is a loss of data due to size growing, may not have a sever impact.
offHeapEntries Indicates the total number of cache entries stored in off-heap memory. Number

The number should be optimal and should be tracked against the maximum size as decided by administrators.
offHeapEvictions Indicates the total number of cache evictions from off-heap memory during the last measurement period. Number

The high number of evictions indicate the cache is not able to serve data properly.
offHeapGets Indicates the total number of get requests made off-heap cache during the last measurement period. Number

A very high number of get requests can lead to slow response from cache.
offHeapHits Indicates the total number of requests made off-heap cache which successfully returned data from cache. Number

 
offHeapHitPercentage Indicates the percentage of requests made off-heap cache which successfully returned data from cache, against total number of requests. Percentage

Ideally this number should be high.
offHeapMisses Indicates the total number of requests made off-heap cache which did not return any data from cache. Number

A very high number of cache misses means either cache is not refreshed for a long time or data being requested is mostly new.
offHeapMissPercentage Indicates the percentage of requests made off-heap cache which did not return data from cache, against total number of requests. Percentage

 
offHeapPrimaryEntries Indicates the total number of cache entries stored in off-heap memory which are not backup entries. Number

This means that off-heap cache is being used to store primary data and needs to be strictly monitored so that there is no data loss.
offHeapPuts Indicates the total number of requests made off-heap cache which resulted in cache update. Number

If there is very large number of cache updates or deletes means that data is no being refreshed frequently.
offHeapRemovals Indicates the total number of requests made off-heap cache which resulted in cache delete. Number