Varnish
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.
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.
| Name | Description | Default | Required |
|---|---|---|---|
| instance_name | the name of the varnishd instance to get logs from. If not specified, the local host name is used. | True | |
| update_every | Sets the default data collection frequency. | 10 | False |
| priority | Controls the order of charts at the netdata dashboard. | 60000 | False |
| autodetection_retry | Sets the job re-check interval in seconds. | 0 | False |
| penalty | Indicates whether to apply penalty to update_every in case of failures. | yes | False |
| 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. |
False |
Examples
Basic
An example configuration.
job_name:
instance_name: '<name-of-varnishd-instance>'
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:
| Metric | Dimensions | Unit |
|---|---|---|
| varnish.session_connection | accepted, dropped | connections/s |
| varnish.client_requests | received | requests/s |
| varnish.all_time_hit_rate | hit, miss, hitpass | percentage |
| varnish.current_poll_hit_rate | hit, miss, hitpass | percentage |
| varnish.cached_objects_expired | objects | expired/s |
| varnish.cached_objects_nuked | objects | nuked/s |
| varnish.threads_total | None | number |
| varnish.threads_statistics | created, failed, limited | threads/s |
| varnish.threads_queue_len | in queue | requests |
| varnish.backend_connections | successful, unhealthy, reused, closed, recycled, failed | connections/s |
| varnish.backend_requests | sent | requests/s |
| varnish.esi_statistics | errors, warnings | problems/s |
| varnish.memory_usage | free, allocated | MiB |
| varnish.uptime | uptime | seconds |
Per Backend
This scope has no labels.
Metrics:
| Metric | Dimensions | Unit |
|---|---|---|
| varnish.backend | header, body | kilobits/s |
Per Storage
This scope has no labels.
Metrics:
| Metric | Dimensions | Unit |
|---|---|---|
| varnish.storage_usage | free, allocated | KiB |
| varnish.storage_alloc_objs | allocated | objects |
Alerts
There are no alerts configured by default for this integration.
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.ddirectory, usually at/usr/libexec/netdata/plugins.d/. If that’s not the case on your system, opennetdata.confand look for thepluginssetting under[directories].cd /usr/libexec/netdata/plugins.d/ -
Switch to the
netdatauser.sudo -u netdata -s -
Run the
python.d.pluginto debug the collector:./python.d.plugin varnish debug trace