Monitoring Memcached

Configuration

To enable in-depth metric monitoring, the agent requires user credentials to access monitoring information. You can configure it in the agent here <agent_install_dir>/etc/instana/configuration.yml:

com.instana.plugin.memcached:
  user: ''
  password: ''

Metrics collection

Configuration data

  • Version
  • Port
  • Storage Limit
  • Max connections
  • Start time

Performance metrics

Metric Description Granularity
Gets Rate of get commands. 1 second
Sets Rate of set commands. 1 second
Reads Rate of bytes read from the network by this server. 1 second
Writes Rate of bytes written to the network by this server. 1 second
Get Hits Rate at which keys are requested and found present. 1 second
Get Misses Rate at which keys are requested and not found present. 1 second
Get Hit Ratio Percentage of requested keys that are found present. 1 second
Delete Hits Rate at which delete commands result in items being removed. 1 second
Delete Misses Rate at which delete commands result in no items being removed. 1 second
Delete Hit Ratio Percentage of delete commands that result in items being removed. 1 second
Flush Command Rate of flush_all commands. 1 second
Evictions Rate at which valid items are removed from cache to free memory for new items. 1 second
Used Bytes Current number of bytes used by this server to store items. 1 second
Connected Number of open connections to this server. 1 second
Queued Number of queued connections to this server. 1 second
Yields Number of times any connection yielded to another due to hitting the -R limit. 1 second
Total Connections Total connections is the number of connections that have been made to the server. 1 second

Health Signatures

For each sensor, there is a curated knowledgebase of health signatures that are evaluated continuously against the incoming metrics and are used to raise issues or incidents depending on user impact.

Built-in events trigger issues or incidents based on failing health signatures on entities, and custom events trigger issues or incidents based on the thresholds of an individual metric of any given entity.

For information about built-events for the Memcached sensor, see the Built-in events reference.