Expvar (Go) 🔗

The Splunk Distribution of OpenTelemetry Collector uses the Smart Agent receiver with the expvar monitor type to scrape metrics exposed by expvar.

The integration uses configured paths to get metric and dimension values from fetched JSON objects at an HTTP endpoint. The Metrics section in this document shows metrics derived from expvar variable memstats, which is exposed by default. These memstat metrics are referred to as standard or default metrics.

Benefits 🔗

After you configure the integration, you can access these features:

View metrics. You can create your own custom dashboards, and most monitors provide built-in dashboards as well. For information about dashboards, see View dashboards in Observability Cloud.
View a data-driven visualization of the physical servers, virtual machines, AWS instances, and other resources in your environment that are visible to Infrastructure Monitoring. For information about navigators, see Splunk Infrastructure Monitoring navigators.
Access the Metric Finder and search for metrics sent by the monitor. For information, see Use the Metric Finder.

Installation 🔗

Follow these steps to deploy this integration:

Deploy the Splunk Distribution of OpenTelemetry Collector to your host or container platform:
Configure the monitor, as described in the Configuration section.
Restart the Splunk Distribution of OpenTelemetry Collector.

Configuration 🔗

To use this integration of a Smart Agent monitor with the Collector:

Include the Smart Agent receiver in your configuration file.
Add the monitor type to the Collector configuration, both in the receiver and pipelines sections.

Read more on how to Use Smart Agent monitors with the Collector.
See how to set up the Smart Agent receiver.
Learn about config options in Collector default configuration.

Example 🔗

To activate this integration, add the following to your Collector configuration:

receivers:
  smartagent/expvar:
    type: expvar
    ... # Additional config

Next, add the monitor to the service > pipelines > metrics > receivers section of your configuration file:

service:
  pipelines:
    metrics:
      receivers: [smartagent/expvar]

Configuration settings 🔗

The following tables show the configuration options for this monitor:

Option	Required	Type	Description
`host`	yes	`string`	Host of the expvar endpoint
`port`	yes	`integer`	Port of the expvar endpoint
`useHTTPS`	no	`bool`	If `true`, the agent will connect to the host using HTTPS instead of plain HTTP. (default: `false`)
`skipVerify`	no	`bool`	If useHTTPS is `true` and this option is also `true`, the host TLS cert will not be verified. (default: `false`)
`path`	no	`string`	Path to the expvar endpoint, usually `/debug/vars` (the default). (default: `/debug/vars`)
`enhancedMetrics`	no	`bool`	If `true`, sends metrics memstats.alloc, memstats.by_size.size, memstats.by_size.mallocs and memstats.by_size.frees (default: `false`)
`metrics`	no	`list of objects (see below)`	Metrics configurations

The nested metrics configuration object has the following fields:

Option	Required	Type	Description
`name`	no	`string`	Metric name
`JSONPath`	yes	`string`	JSON path of the metric value
`type`	yes	`string`	SignalFx metric type. Possible values are “gauge” or “cumulative”
`dimensions`	no	`list of objects (see below)`	Metric dimensions
`pathSeparator`	no	`string`	Path separator character of metric value in JSON object (default: `.`)

The nested dimensions configuration object has the following fields:

Option	Required	Type	Description
`name`	yes	`string`	Dimension name
`JSONPath`	no	`string`	JSON path of the dimension value
`value`	no	`string`	Dimension value

Metrics 🔗

Do not configure the monitor for memstats metrics because they are standard metrics provided by default. The following metrics are also available for this integration:

Notes 🔗

Learn more about the available metric types in Observability Cloud.
Default metrics are those metrics included in host-based subscriptions in Observability Cloud, such as host, container, or bundled metrics. Custom metrics are not provided by default and might be subject to charges. See more about metric categories.
To add additional metrics, see how to configure extraMetrics using the Collector.

Troubleshooting 🔗

If you are not able to see your data in Splunk Observability Cloud, try these tips:

Submit a case in the Splunk Support Portal
- Available to Splunk Observability Cloud customers
Call Splunk Customer Support
- Available to Splunk Observability Cloud customers
Ask a question and get answers through community support at Splunk Answers
- Available to Splunk Observability Cloud customers and free trial users
Join the Splunk #observability user group Slack channel to communicate with customers, partners, and Splunk employees worldwide
- Available to Splunk Observability Cloud customers and free trial users
- To learn how to join, see Get Started with Splunk Community - Chat groups

To learn about even more support options, see Splunk Customer Success.

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