Advanced configuration for Windows

Optional configurations for the Splunk Distribution of OpenTelemetry Collector for Windows.

The Collector comes with a default configuration. To learn more, see Collector for Windows default configuration.

Change the default configuration file for the Collector for Windows

All installation methods offer default configurations using environment variables. Before starting the splunk-otel-collector service, replace the variables in the default configuration file with the appropriate values for your environment.

Splunk-specific environment variables are listed on the table below:


Name	Description	Default config?
`SPLUNK_ACCESS_TOKEN`	The Splunk access token to authenticate requests	Yes
`SPLUNK_API_URL`	The Splunk API URL. For example, https://api.us0.signalfx.com	Yes
`SPLUNK_BALLAST_SIZE_MIB` (deprecated)	`memory_ballast` is deprecated. If you’re using this variable, see how to update your configuration.	No
`SPLUNK_BUNDLE_DIR`	The path to the Smart Agent bundle. For example, `/usr/lib/splunk-otel-collector/agent-bundle`	Yes
`SPLUNK_COLLECTD_DIR`	The path to the collectd config directory for the Smart Agent. For example, `/usr/lib/splunk-otel-collector/agent-bundle/run/collectd`	Yes
`SPLUNK_CONFIG`	Destination path of the Collector custom configuration file	No
`SPLUNK_CONFIG_YAML`	Specifies your custom configuration YAML. This is useful in environments where access to the underlying file system is not readily available	No
`SPLUNK_DEBUG_CONFIG_SERVER`	By default, the Collector provides a sensitive value-redacting, local config server listening at http://localhost:55554/debug/configz/effective, which is helpful in troubleshooting. To disable it, set `SPLUNK_DEBUG_CONFIG_SERVER` to any value other than `true`. To set the desired port to listen to, use `SPLUNK_DEBUG_CONFIG_SERVER_PORT`	No
`SPLUNK_HEC_TOKEN`	The Splunk HEC authentication token	Yes
`SPLUNK_HEC_URL`	The Splunk HEC endpoint URL. For example, https://ingest.us0.signalfx.com/v1/log	Yes
`SPLUNK_INGEST_URL`	The Splunk ingest URL. For example, https://ingest.us0.signalfx.com	Yes
`SPLUNK_LISTEN_INTERFACE`	The network interface the agent receivers listen on. `0.0.0.0` by default	Yes
`SPLUNK_MEMORY_LIMIT_MIB`	Use it to set the memory limit for the `memory_limiter` processor. 512 MiB by default	No
`SPLUNK_MEMORY_TOTAL_MIB`	Total memory in MiB to allocate to the Collector	No
`SPLUNK_REALM`	Your Splunk realm	No
`SPLUNK_TRACE_URL`	The Splunk trace endpoint URL. For example, https://ingest.us0.signalfx.com/v2/trace	Yes

SPLUNK_*_URL environment variables are automatically derived from SPLUNK_REALM. For example, SPLUNK_INGEST_URL = https://ingest.SPLUNK_REALM.signalfx.com.

Note: When configuring additional settings, use service, process, or terminal scopes.

Based on the specified installation parameters, the environment variables are saved to the HKLM:\SYSTEM\CurrentControlSet\Services\splunk-otel-collector registry key and set on the Environment entry.

To modify any of the configuration values, run regedit and browse to the path.

Configure memory allocation

To configure memory allocation, use the memory parameter, which sets the environment variable SPLUNK_MEMORY_TOTAL_MIB.

By default, the Collector is configured to use 512 MiB of memory.
To modify this setting, replace SPLUNK_MEMORY_TOTAL_MIB with the desired integer value.

& {Set-ExecutionPolicy Bypass -Scope Process -Force; $script = ((New-Object System.Net.WebClient).DownloadString('https://dl.signalfx.com/splunk-otel-collector.ps1')); $params = @{access_token = "SPLUNK_ACCESS_TOKEN"; realm = "SPLUNK_REALM"; memory = "SPLUNK_MEMORY_TOTAL_MIB"}; Invoke-Command -ScriptBlock ([scriptblock]::Create(". {$script} $(&{$args} @params)"))}

Read more about Collector sizing in Sizing and scaling.

Configure proxy settings

To configure proxy settings to install and run the OpenTelemetry Collector, see Configure proxy settings for the Collector.

Command line options

To add or remove command line options for the splunk-otel-collector service, run regedit and modify the ImagePath value in the HKLM:\SYSTEM\CurrentControlSet\Services\splunk-otel-collector registry key.

Alternatively, run the following PowerShell command, replacing OPTIONS with the desired command line options:

Set-ItemProperty -path "HKLM:\SYSTEM\CurrentControlSet\Services\splunk-otel-collector" -name "ImagePath" -value "C:\Program Files\Splunk\OpenTelemetry Collector\otelcol.exe OPTIONS"

For example, to change the default exposed metrics address of the Collector to 0.0.0.0:9090, run the following PowerShell command:

Set-ItemProperty -path "HKLM:\SYSTEM\CurrentControlSet\Services\splunk-otel-collector" -name "ImagePath" -value "C:\Program Files\Splunk\OpenTelemetry Collector\otelcol.exe --metrics-addr 0.0.0.0:9090"

Apply the changes

After modifying the configuration file or registry key, apply the changes by restarting the system or running the following PowerShell commands:

Stop-Service splunk-otel-collector
Start-Service splunk-otel-collector

Available command line options

To see all available command line options, run the following PowerShell command:

& 'C:\Program Files\Splunk\OpenTelemetry Collector\otelcol.exe' --help

Documentation