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.
If no configuration is given, collector will attempt to connect to memcached instance on 127.0.0.1:11211
address.
The default configuration for this integration does not impose any limits on data collection.
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:
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. | 127.0.0.1 | 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.
localhost:
name: 'local'
host: 'localhost'
port: 11211
An example configuration for localipv4.
localhost:
name: 'local'
host: '127.0.0.1'
port: 11211
An example configuration for localipv6.
localhost:
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.
These metrics refer to the entire monitored application.
This scope has no labels.
Metrics:
Metric | Dimensions | Unit |
---|---|---|
memcached.cache | available, used | MiB |
memcached.net | 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 |
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
If you’re encountering problems with the memcached
collector, follow these steps to retrieve logs and identify potential issues:
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
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.
If your Netdata runs in a Docker container named “netdata” (replace if different), use this command:
docker logs netdata 2>&1 | grep memcached