Memcached icon



Plugin: python.d.plugin Module: memcached


Monitor Memcached metrics for proficient in-memory key-value store operations. Track cache hits, misses, and memory usage for efficient data caching.

It reads server response to stats command (stats interface).

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Default Behavior


If no configuration is given, collector will attempt to connect to memcached instance on address.


The default configuration for this integration does not impose any limits on data collection.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.



No action required.



The configuration file name for this integration is python.d/memcached.conf.

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config python.d/memcached.conf


There are 2 sections:

  • Global variables
  • One or more JOBS that can define multiple different instances to monitor.

The following options can be defined globally: priority, penalty, autodetection_retry, update_every, but can also be defined per JOB to override the global values.

Additionally, the following collapsed table contains all the options that can be configured inside a JOB definition.

Every configuration JOB starts with a job_name value which will appear in the dashboard, unless a name parameter is specified.

Name Description Default Required
host the host to connect to. no
port the port to connect to. 11211 no
update_every Sets the default data collection frequency. 10 no
priority Controls the order of charts at the netdata dashboard. 60000 no
autodetection_retry Sets the job re-check interval in seconds. 0 no
penalty Indicates whether to apply penalty to update_every in case of failures. yes no
name Job name. This value will overwrite the job_name value. JOBS with the same name are mutually exclusive. Only one of them will be allowed running at any time. This allows autodetection to try several alternatives and pick the one that works. no



An example configuration for localhost.

  name: 'local'
  host: 'localhost'
  port: 11211


An example configuration for localipv4.

  name: 'local'
  host: ''
  port: 11211


An example configuration for localipv6.

  name: 'local'
  host: '::1'
  port: 11211


Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per Memcached instance

These metrics refer to the entire monitored application.

This scope has no labels.


Metric Dimensions Unit
memcached.cache available, used MiB in, out kilobits/s
memcached.connections current, rejected, total connections/s
memcached.items current, total items
memcached.evicted_reclaimed reclaimed, evicted items
memcached.get hints, misses requests
memcached.get_rate rate requests/s
memcached.set_rate rate requests/s
memcached.delete hits, misses requests
memcached.cas hits, misses, bad value requests
memcached.increment hits, misses requests
memcached.decrement hits, misses requests
memcached.touch hits, misses requests
memcached.touch_rate rate requests/s


The following alerts are available:

Alert name On metric Description
memcached_cache_memory_usage memcached.cache cache memory utilization
memcached_cache_fill_rate memcached.cache average rate the cache fills up (positive), or frees up (negative) space over the last hour
memcached_out_of_cache_space_time memcached.cache estimated time the cache will run out of space if the system continues to add data at the same rate as the past hour


Debug Mode

To troubleshoot issues with the memcached collector, run the python.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn’t working.

  • Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that’s not the case on your system, open netdata.conf and look for the plugins setting under [directories].

    cd /usr/libexec/netdata/plugins.d/
  • Switch to the netdata user.

    sudo -u netdata -s
  • Run the python.d.plugin to debug the collector:

    ./python.d.plugin memcached debug trace

Getting Logs

If you’re encountering problems with the memcached collector, follow these steps to retrieve logs and identify potential issues:

  • Run the command specific to your system (systemd, non-systemd, or Docker container).
  • Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep memcached

System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector’s name:

grep memcached /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

Docker Container

If your Netdata runs in a Docker container named “netdata” (replace if different), use this command:

docker logs netdata 2>&1 | grep memcached

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