The Varnish integration collects cache and session metrics.
It monitors the number of objects entering and exiting the cache,
as well as the number of sessions and backend connections.
The integration also collects Varnish logs and parses them
into a standardized JSON payload.
For more information about Varnish, see the
Varnish
HTTP Cache documentation
.
Prerequisites
To collect Varnish telemetry, you must
install the Ops Agent
:
- For metrics, install version 2.15.0 or higher.
- For logs, install version 2.16.0 or higher.
This integration supports Varnish versions 6.x and 7.0.x.
The Varnish logging processor processes logs using
varnishncsa
.
Varnish can enable varnishncsa logging by following this
guide
,
depending on the operating system.
By default, logs are written to
/var/log/varnish/varnishncsa.log
. If you
choose another destination, you must update the receiver configuration.
Logs are expected to be in the default format, and a log rotation should be
set up.
Following the guide to
configure the Ops
Agent
, add the required elements
to collect telemetry from Varnish instances, and
restart the agent
.
Example configuration
The following command creates the configuration to collect and ingest
telemetry for Varnish and restarts the Ops Agent on Linux.
Configure logs collection
To ingest logs from Varnish, you must create receivers for the logs
that Varnish produces and then create a pipeline for the new receivers.
To configure a receiver for your
varnish
logs, specify the following
fields:
Field
|
Default
|
Description
|
exclude_paths
|
|
A list of filesystem path patterns to exclude from the set matched by include_paths.
|
include_paths
|
[/var/log/varnish/varnishncsa.log]
|
A varnishncsa default log path to read by tailing each file.
|
record_log_file_path
|
false
|
If set to
true
, then the path to the specific file from which the log record was obtained appears in the output log entry as the value of the
agent.googleapis.com/log_file_path
label. When using a wildcard, only the path of the file from which the record was obtained is recorded.
|
type
|
|
This value must be
varnish
.
|
wildcard_refresh_interval
|
60s
|
The interval at which wildcard file paths in include_paths are refreshed. Given as a time duration, for example, 30s or 2m. This property might be useful under high logging throughputs where log files are rotated faster than the default interval.
|
What is logged
The
logName
is derived from the receiver IDs specified in the configuration.
Detailed fields inside the
LogEntry
are as follows.
varnish
logs contain the following fields in the
LogEntry
:
Field
|
Type
|
Description
|
httpRequest
|
object
|
See
HttpRequest
|
jsonPayload.host
|
string
|
Contents of the Host header
|
jsonPayload.user
|
string
|
Authenticated username for the request
|
severity
|
string (
LogSeverity
)
|
Log entry level (translated).
|
Configure metrics collection
To ingest metrics from Varnish, you must create a receiver for the
metrics that Varnish produces and then create a pipeline for the
new receiver.
This receiver does not
support the use of multiple instances in the configuration, for example, to
monitor multiple endpoints. All such instances write to the same time series,
and Cloud Monitoring has no way to distinguish among them.
To configure a receiver for your
varnish
metrics, specify the following
fields:
Field
|
Default
|
Description
|
cache_dir
|
|
This specifies the cache dir instance name to use when collecting metrics. If not specified, defaults to the host.
|
collection_interval
|
60s
|
A
time.Duration
value, such as
30s
or
5m
.
|
exec_dir
|
|
The directory where the
varnishadm
and
varnishstat
executables are located. If not provided, the user's
PATH
setting is used.
|
type
|
|
This value must be
varnish
.
|
What is monitored
The following table provides the list of metrics that the Ops Agent collects
from the Varnish instance.
Metric type
|
Kind, Type
Monitored resources
|
Labels
|
workload.googleapis.com/varnish.backend.connection.count
|
CUMULATIVE
,
INT64
gce_instance
|
kind
|
workload.googleapis.com/varnish.backend.request.count
|
CUMULATIVE
,
INT64
gce_instance
|
|
workload.googleapis.com/varnish.cache.operation.count
|
CUMULATIVE
,
INT64
gce_instance
|
operation
|
workload.googleapis.com/varnish.client.request.count
|
CUMULATIVE
,
INT64
gce_instance
|
state
|
workload.googleapis.com/varnish.client.request.error.count
|
CUMULATIVE
,
INT64
gce_instance
|
status_code
|
workload.googleapis.com/varnish.object.count
|
GAUGE
,
INT64
gce_instance
|
|
workload.googleapis.com/varnish.object.expired
|
CUMULATIVE
,
INT64
gce_instance
|
|
workload.googleapis.com/varnish.object.moved
|
CUMULATIVE
,
INT64
gce_instance
|
|
workload.googleapis.com/varnish.object.nuked
|
CUMULATIVE
,
INT64
gce_instance
|
|
workload.googleapis.com/varnish.session.count
|
CUMULATIVE
,
INT64
gce_instance
|
kind
|
workload.googleapis.com/varnish.thread.operation.count
|
CUMULATIVE
,
INT64
gce_instance
|
operation
|
Verify the configuration
This section describes how to verify that you correctly configured the
Varnish receiver. It might take one or two
minutes for the Ops Agent to begin collecting telemetry.
To verify that Varnish logs are being sent to
Cloud Logging, do the following:
-
In the Google Cloud console, go to the
Logs Explorer
page:
Go to
Logs Explorer
If you use the search bar to find this page, then select the result whose subheading is
Logging
.
- Enter the following query in the editor, and then click
Run query
:
resource.type="gce_instance"
log_id("varnish")
To verify that Varnish metrics are being sent to
Cloud Monitoring, do the following:
-
In the Google Cloud console, go to the
leaderboard
Metrics explorer
page:
Go to
Metrics explorer
If you use the search bar to find this page, then select the result whose subheading is
Monitoring
.
- In the toolbar of the
query-builder pane, select the button whose name is either
code
MQL
or
code
PromQL
.
- Verify that
MQL
is selected
in the
Language
toggle. The language toggle is in the same toolbar that
lets you format your query.
- Enter the following query in the editor, and then click
Run query
:
fetch gce_instance
| metric 'workload.googleapis.com/varnish.backend.connection.count'
| every 1m
View dashboard
To view your Varnish metrics, you must have a chart or dashboard
configured.
The Varnish integration includes one or more dashboards for you.
Any dashboards are automatically installed after you configure the
integration and the Ops Agent has begun collecting metric data.
You can also view static previews of dashboards without
installing the integration.
To view an installed dashboard, do the following:
-
In the Google Cloud console, go to the
Dashboards
page:
Go to
Dashboards
If you use the search bar to find this page, then select the result whose subheading is
Monitoring
.
- Select the
Dashboard List
tab, and then choose the
Integrations
category.
- Click the name of the dashboard you want to view.
If you have configured an integration but the dashboard has not been
installed, then check that the Ops Agent is running. When there is no
metric data for a chart in the dashboard, installation of the dashboard fails.
After the Ops Agent begins collecting metrics, the dashboard is installed
for you.
To view a static preview of the dashboard, do the following:
-
In the Google Cloud console, go to the
Integrations
page:
Go to
Integrations
If you use the search bar to find this page, then select the result whose subheading is
Monitoring
.
- Click the
Compute Engine
deployment-platform filter.
- Locate the entry for
Varnish
and click
View Details
.
- Select the
Dashboards
tab to see a static preview. If the
dashboard is installed, then you can navigate to it by clicking
View dashboard
.
For more information about dashboards in Cloud Monitoring, see
Dashboards and charts
.
For more information about using the
Integrations
page, see
Manage integrations
.
Install alerting policies
Alerting policies instruct Cloud Monitoring to notify you when
specified conditions occur.
The Varnish integration includes one or more alerting policies for
you to use.
You can view and install
these alerting policies from the
Integrations
page in
Monitoring.
To view the descriptions of available alerting policies and
install them, do the following:
-
In the Google Cloud console, go to the
Integrations
page:
Go to
Integrations
If you use the search bar to find this page, then select the result whose subheading is
Monitoring
.
- Locate the entry for
Varnish
and click
View Details
.
- Select the
Alerts
tab. This tab provides descriptions of
available alerting policies and provides an interface for installing
them.
- Install alerting policies. Alerting policies need
to know where to send notifications that the alert has been
triggered, so they require information from you for installation.
To install alerting policies, do the following:
- From the list of available alerting policies,
select those that you want to install.
In the
Configure notifications
section, select one or
more notification channels. You have the option to disable the
use of notification channels, but if you do, then your alerting
policies fire silently. You can check their status in
Monitoring, but you receive no notifications.
For more information about notification channels,
see
Manage
notification channels
.
- Click
Create Policies
.
For more information about alerting policies in Cloud Monitoring, see
Introduction to alerting
.
For more information about using the
Integrations
page, see
Manage integrations
.
What's next
For a walkthrough on how to use Ansible to install the Ops Agent, configure a
third-party application, and install a sample dashboard, see the
Install the Ops Agent to troubleshoot third-party applications
video.