Settings for Call Graph Profiling

The following settings control the Call Graph Profiling feature.

Java

System properties	Description	Default value
splunk.snapshot.profiler.enabled	Enables the snapshot profiler required for call graph generation.	false
splunk.snapshot.profiler.sampling.interval	Sampling interval (e.g., 10ms). Lower values increase stack capture frequency.	10ms
splunk.snapshot.selection.probability	Probability of selecting a trace for snapshot profiling. Maximum value is 0.10.	0.01
splunk.snapshot.profiler.max.stack.depth	Maximum depth of captured call stacks.	1024
splunk.snapshot.profiler.export.interval	Interval for exporting collected stack data.	5s
splunk.snapshot.profiler.staging.capacity	Capacity of the staging buffer before export.	2000

Note: These settings can be passed as JVM system properties or as environment variables depending on your deployment model.

Recommended settings to increase visibility

Use the following configuration adjustments to reduce the likelihood of missing stack data:

Environment variable	Recommendation
splunk.snapshot.profiler.sampling.interval	Lower to 1 ms to maximize sampling frequency.
splunk.snapshot.selection.probability	Raise to 0.05 or 0.1 to include more traces.

Note: These adjustments may increase resource usage. Test changes in staging environments before applying to production.

.NET

Environment variable	Description	Default value
SPLUNK_SNAPSHOT_PROFILER_ENABLED	Enables the snapshot profiler required for call graph generation.	false
SPLUNK_SNAPSHOT_SAMPLING_INTERVAL	Sampling interval. Lower values increase stack capture frequency.	40ms
SPLUNK_SNAPSHOT_SELECTION_PROBABILITY	Probability of selecting a trace for snapshot profiling. Maximum value is 0.10.	0.01
SPLUNK_PROFILER_EXPORT_INTERVAL	Interval for exporting collected stack data. Minimum value: 500ms.	500ms
SPLUNK_PROFILER_EXPORT_TIMEOUT	Timeout for exporting stack data, in milliseconds.	3000ms
SPLUNK_PROFILER_MAX_MEMORY_SAMPLES	Maximum memory samples collected per minute. Max value:500	200

Note: If both snapshot and continuous profilers are enabled, consider reducing SPLUNK_PROFILER_EXPORT_INTERVALto avoid buffer overflows. A good practice is to set it to half of the continuous profiler’s sampling interval.

Compatibility with Continuous Profiler

If thread sampling via the continuous profiler is enabled (SPLUNK_PROFILER_ENABLED=true), the value of SPLUNK_PROFILER_CALL_STACK_INTERVAL must be greater than and a multiple of SPLUNK_SNAPSHOT_SAMPLING_INTERVAL. For example, the default values — 10s and 40ms — satisfy this requirement.

Recommended settings to increase visibility

Use the following configuration adjustments to reduce the likelihood of missing stack data:

Environment variable	Recommendation
SPLUNK_SNAPSHOT_SAMPLING_INTERVAL	Lower to increase sampling frequency.
SPLUNK_SNAPSHOT_SELECTION_PROBABILITY	Raise to 0.05 or 0.1 to include more traces.

Note: These adjustments may increase resource usage. Test changes in staging environments before applying to production.

Node.js

Environment variable	Description	Default value
SPLUNK_SNAPSHOT_PROFILER_ENABLED	Enables the snapshot profiler required for call graph generation.	false
SPLUNK_SNAPSHOT_SAMPLING_INTERVAL	Sampling interval in milliseconds. Lower values increase stack capture frequency.	10
SPLUNK_SNAPSHOT_SELECTION_PROBABILITY	Percentage of traces selected for snapshot profiling. Maximum value is 1.	0.01
SPLUNK_CPU_PROFILER_COLLECTION_INTERVAL	Interval (ms) for exporting collected call stacks from the native extension.	30000

Note: Adjust sampling and selection rates based on your application's workload and performance sensitivity. Lower intervals increase visibility but may introduce overhead

Recommended settings to increase visibility

Use the following configuration adjustments to reduce the likelihood of missing stack data:

Environment variable	Recommendation
SPLUNK_SNAPSHOT_PROFILER_SAMPLING_INTERVAL	Lower to 1 ms to increase sampling frequency.
SPLUNK_SNAPSHOT_SELECTION_RATE	Raise to 0.05 or 0.1 to include more traces.

Note: These adjustments may increase resource usage. Test changes in staging environments before applying to production.