Monitoring Memcached
The Memcached sensor is automatically deployed and installed after you install the Instana agent.
Support information
To make sure that the Memcached sensor is compatible with your current setup, check the following support information sections:
Supported versions and support policy
The following table shows the latest supported version and support policy:
| Technology | Support policy | Latest version | Latest supported version |
|---|---|---|---|
| Memcached | 45 days | 1.6.34 | 1.6.34 |
For more information about the support policy, see Support strategy for sensors.
Supported client-side tracing
For this technology, Instana supports client-side tracing for the following languages and runtimes:
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: ''
Viewing metrics
To view the metrics, complete the following steps:
- From the sidebar of the Instana UI, select Infrastructure.
- Click a specific monitored host.
You can see a host dashboard with all the collected metrics and monitored processes.
Configuration data
- Version
- Port
- Storage limit
- Max connections
- Start time
Performance metrics
The following table lists the 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 are the number of connections that have been made to the server. | 1 second |
Health signatures
For each sensor, there is a curated knowledge base 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.