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Measures reported by RedisServerTest
The two most important factors that influence the performance level of the Redis server, are:
Keyspace hits/misses Server latency
A keyspace miss means some piece of data you tried to retrieve from Redis was not there. If this happens very often, it can adversely impact user satisfaction with the Redis server.
Latency measures the average time it takes the Redis server to respond. Since a single process on the Redis server serves all client requests, one slow client request can delay the processing of other requests. Once again, user experience with the Redis server will suffer. By monitoring keyspace usage and latency closely, the RedisServerTest test brings frequent keyspace misses and request processing bottlenecks to the immediate attention of administrators. This prompts administrators to investigate, isolate, and eliminate the root-cause of these issues, thereby improving overall Redis server performance and the user experience with it.
Outputs of the test : One set of results for the target Redis server
The measures made by this test are as follows:
| Measurement |
Description |
Measurement Unit |
Interpretation |
| key_space_hit_ratio |
Indicates the percentage of requests to the keyspace that were serviced successfully. |
Percent |
Keyspace refers to the internal dictionary that Redis manages, in which all keys are stored
The value of this measure is computed using the formula:
(Total key hits)/ (Total keys hits + Total key misses)
Ideally, the value of this measure should be higher than 80%. A lower value implies that the keyspace is consistently failing to service requests it receives, because the data being requested is not available in the keyspace. This usually means that one of the following happened:
The key expired They key was renamed The key was deleted The key was evicted due to memory pressure The entire database was flushed The key was never actually inserted The data was lost due to a crash,failover, etc The data is in a different DB than the one you currently selected
A lower hit ratio results in larger latency as most of the requests are fetching data from the disk. It indicates that you need to increase the size of the keyspace to improve your application's performance. |
| latency |
Indicates the average time the Redis server took to respond to client requests |
Milliseconds |
A low value is desired for this measure.
An unusually high value is a cause for concern, as it implies that the Redis server is not responding quickly to requests. Common causes for high latencies are:
Ideally, the value of this measure should be higher than 80%. A lower value implies that the keyspace is consistently failing to service requests it receives, because the data being requested is not available in the keyspace. This usually means that one of the following happened:
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