In Redis, an eviction is the process of removing keys to make space for new data when memory is full. Redis offers a wide range of strategies to manage these evictions. If you want to monitor key evictions, you can use a combination of Redis commands and configuration settings.
Firstly, ensure that your eviction policy is set. Redis provides various policies like
volatile-lru, etc. You can set this using the
maxmemory-policy configuration directive in your
Also make sure to set the
maxmemory configuration directive to trigger the eviction when memory reaches the defined limit.
You can use the
INFO command to get statistics about the Redis server, including evictions. The
info command returns multiple fields; the one we're interested in is
evicted_keys, which shows the number of keys that have been evicted due to max memory limit.
For active monitoring, you can also use the
MONITOR command, which streams every command processed by the Redis server. However, bear in mind that the
MONITOR command can significantly reduce the performance of your Redis server as it has to send back all processed commands.
MONITOR command, you can detect operations like
DEL which might be part of the eviction process (depending on the
Additionally, if you want more granular control or automated alerts based on evictions, consider using an application performance management tool like New Relic or Datadog that supports Redis.