Skip to main content

Varnish

Plugin: python.d.plugin Module: varnish

Overview

This collector monitors Varnish metrics about HTTP accelerator global, Backends (VBE) and Storages (SMF, SMA, MSE) statistics.

Note that both, Varnish-Cache (free and open source) and Varnish-Plus (Commercial/Enterprise version), are supported.

It uses the varnishstat tool in order to collect the metrics.

This collector is supported on all platforms.

This collector only supports collecting metrics from a single instance of this integration.

netdata user must be a member of the varnish group.

Default Behavior

Auto-Detection

By default, if the permissions are satisfied, the varnishstat tool will be executed on the host.

Limits

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.

Metrics

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 Varnish instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

MetricDimensionsUnit
varnish.session_connectionaccepted, droppedconnections/s
varnish.client_requestsreceivedrequests/s
varnish.all_time_hit_ratehit, miss, hitpasspercentage
varnish.current_poll_hit_ratehit, miss, hitpasspercentage
varnish.cached_objects_expiredobjectsexpired/s
varnish.cached_objects_nukedobjectsnuked/s
varnish.threads_totalNonenumber
varnish.threads_statisticscreated, failed, limitedthreads/s
varnish.threads_queue_lenin queuerequests
varnish.backend_connectionssuccessful, unhealthy, reused, closed, recycled, failedconnections/s
varnish.backend_requestssentrequests/s
varnish.esi_statisticserrors, warningsproblems/s
varnish.memory_usagefree, allocatedMiB
varnish.uptimeuptimeseconds

Per Backend

This scope has no labels.

Metrics:

MetricDimensionsUnit
varnish.backendheader, bodykilobits/s

Per Storage

This scope has no labels.

Metrics:

MetricDimensionsUnit
varnish.storage_usagefree, allocatedKiB
varnish.storage_alloc_objsallocatedobjects

Alerts

There are no alerts configured by default for this integration.

Setup

Prerequisites

Provide the necessary permissions

In order for the collector to work, you need to add the netdata user to the varnish user group, so that it can execute the varnishstat tool:

usermod -aG varnish netdata

Configuration

File

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

Options

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.

Config options
NameDescriptionDefaultRequired
instance_namethe name of the varnishd instance to get logs from. If not specified, the local host name is used.yes
update_everySets the default data collection frequency.10no
priorityControls the order of charts at the netdata dashboard.60000no
autodetection_retrySets the job re-check interval in seconds.0no
penaltyIndicates whether to apply penalty to update_every in case of failures.yesno
nameJob 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

Examples

Basic

An example configuration.

job_name:
instance_name: '<name-of-varnishd-instance>'

Troubleshooting

Debug Mode

To troubleshoot issues with the varnish 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 varnish debug trace

Do you have any feedback for this page? If so, you can open a new issue on our netdata/learn repository.