Varnish
Varnish
Plugin: go.d.plugin Module: varnish
Overview
This collector monitors Varnish instances, supporting both the open-source Varnish-Cache and the commercial Varnish-Plus.
It tracks key performance metrics, along with detailed statistics for Backends (VBE) and Storages (SMF, SMA, MSE).
It relies on the varnishstat CLI tool but avoids directly executing the binary.
Instead, it utilizes ndsudo, a Netdata helper specifically designed to run privileged commands securely within the Netdata environment.
This approach eliminates the need to use sudo, improving security and potentially simplifying permission management.
This collector is supported on all platforms.
This collector supports collecting metrics from multiple instances of this integration, including remote instances.
Default Behavior
Auto-Detection
Automatically detects and monitors Varnish instances running on the host or inside Docker containers.
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
No action required.
Configuration
File
The configuration file name for this integration is go.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 go.d/varnish.conf
Options
The following options can be defined globally: update_every.
| Name | Description | Default | Required |
|---|---|---|---|
| update_every | Data collection frequency. | 10 | no |
| timeout | Timeout for executing the binary, specified in seconds. | 2 | no |
| instance_name | Specifies the name of the Varnish instance to collect metrics from. This corresponds to the -n argument used with the varnishstat command. |
no | |
| docker_container | Specifies the name of the Docker container where the Varnish instance is running. If set, the varnishstat command will be executed within this container. |
no |
Examples
Custom update_every
Allows you to override the default data collection interval.
jobs:
- name: varnish
update_every: 5
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.client_session_connections | accepted, dropped | connections/s |
| varnish.client_requests | received | requests/s |
| varnish.cache_hit_ratio_total | hit, miss, hitpass, hitmiss | percent |
| varnish.cache_hit_ratio_delta | hit, miss, hitpass, hitmiss | percent |
| varnish.cache_expired_objects | expired | objects/s |
| varnish.cache_lru_activity | nuked, moved | objects/s |
| varnish.threads | threads | threads |
| varnish.thread_management_activity | created, failed, destroyed, limited | threads/s |
| varnish.thread_queue_len | queue_length | threads |
| varnish.backends_requests | sent | requests/s |
| varnish.esi_parsing_issues | errors, warnings | issues/s |
| varnish.mgmt_process_uptime | uptime | seconds |
| varnish.child_process_uptime | uptime | seconds |
Per Backend
These metrics refer to the Backend (VBE).
This scope has no labels.
Metrics:
| Metric | Dimensions | Unit |
|---|---|---|
| varnish.backend_data_transfer | req_header, req_body, resp_header, resp_body | bytes/s |
Per Storage
These metrics refer to the Storage (SMA, SMF, MSE).
This scope has no labels.
Metrics:
| Metric | Dimensions | Unit |
|---|---|---|
| varnish.storage_space_usage | free, used | bytes |
| varnish.storage_allocated_objects | allocated | objects |
Alerts
There are no alerts configured by default for this integration.
Troubleshooting
Debug Mode
Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.
To troubleshoot issues with the varnish collector, run the go.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
go.d.pluginto debug the collector:./go.d.plugin -d -m varnish
Getting Logs
If you’re encountering problems with the varnish 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 varnish
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 varnish /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 varnish