Endeca Cache Test

Endeca Server is a hybrid search-analytical engine that organizes complex and varied data from disparate sources and unifies search, navigation, and analytics to deliver fast answers on structured and unstructured data. To ensure peak storage performance the usage of the cache should be continuously monitored, cache misses should be promptly captured, and the reasons for the same should be diagnosed. Therefore, it is imperative that administrators should continuously monitor performance of the cache to ensure better user experience. The Endeca Cache Test helps administrators in this regard.

This test closely monitors the cache, tracks the percentage of cache hits, misses and number of lookups, and alerts administrators if the value deviates from the acceptable limits. In addition, the test also reports the count of evictions, number of reinsertions and rejections, time taken for reinsertion, etc. Using the pointers provided by this test, administrators can fine-tune the cache for best performance.

Target of the test : An Endeca Search Application

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every cache on the Endeca search application being monitored.

Configurable parameters for the test
Parameter	Description
Test period	How often should the test be executed
Host	The IP address of the host for which this test is to be configured.
Port	The port at which the specified host listens to. The default port is 15000.
PerfStatURL	Specify the URL to access the page from which this test will be collecting the required statistics. The default URL will be in the format: http://{Endeca_Server_IP}:8000/admin?op=stats

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
Entry count	Indicates the total number of entry in this cache.	Number	The value of this measure should not exceed the specified maximum number of entries in the cache.
All entry size	Indicates the total size of all entries in this cache.	MB	Ideally, the value of this measure should be low.
Number of lookups	Indicates the number of times this cache was looked up for serving read requests during the last measurement period.	Number
Hits	Indicates the percentage of requests that have been serviced by this cache.	Percent	Ideally the value of this measure should be high.
Misses	Indicates the percentage of requests that have not been serviced by this cache.	Percent	A low value is desired for this measure.
Evictions count	Indicates total number of evictions from this cache.	Number	A high value is desired for this measure. If the percentage of the maximum cache size that is used by the cache is very high and the value of this measure is very low, it can only mean that data is not evicted frequently enough to control cache growth. You may have to fine-tune eviction to ensure that the cache does not grow uncontrollably
Unproductive evictions count	Indicates total number of unproductive evictions from this cache.	Number	Ideally, the value of this measure should be high. This measure can control the cache growth and thereby reduce the risk of available disk space usage and related bottleneck conditions.
Evictions size	Indicates size of eviction from this cache.	MB
Average creation time	Indicates average time taken for creation by this cache.	Seconds	Ideally, the value of this measure should be low.
Average eviction time	Indicates average time taken for eviction by this cache.	Seconds	A low value is desired for this measure.
Average unproductive eviction time	Indicates average time taken for unproductive eviction.	Seconds	A low value is desired for this measure.
Rejected counts	Indicates total number of rejections to this cache.	Number	The value of this measure should be low. A high value is an indication of higher number of potential entry rejections to the entity cache. This indicates that the cache is undersized and you may want to increase it.
Reinsertion counts	Indicates total number of reinsertions in this cache.	Number	The value of this measure indicate the number of queries that are computing the same values.
Reinsertion creation	Indicates time taken for calculating identical results in parallel with other queries.	Seconds	Ideally, the value of this measure should be low.
Eviction candidates per quartile	Indicates total number of evictions per quartile from this cache.	Number	Most of the time the data in the lowest quartile of use is evicted.