Learn about MetricSets in APM 🔗

MetricSets are key performance indicators, like request rate, error rate, and request duration, that are calculated from traces and spans in Splunk APM. There are 2 categories of MetricSets: Troubleshooting MetricSets (TMS), used for high-cardinality troubleshooting, and Monitoring MetricSets (MMS), used for real-time monitoring. MetricSets are similar to the metric time series (MTS) used in Splunk Infrastructure Monitoring to populate charts and generate alerts. See Metric time series to learn more. MetricSets are MTS that are specific to Splunk APM.

Troubleshooting MetricSets 🔗

Troubleshooting MetricSets (TMS) are metric time series (MTS) you can use for troubleshooting high-cardinality identities in APM. You can also use TMS to make historical comparisons across spans and workflows.

Splunk APM indexes and creates Troubleshooting MetricSets for several span tags by default. For more details about each of these tags, see Default indexed span tags in APM. You can’t modify or stop APM from indexing these span tags.

You can also create custom TMS by indexing additional span tags and processes. To learn how to index span tags and processes to create new Troubleshooting MetricSets, see Index span tags to create Troubleshooting MetricSets.

Available TMS metrics 🔗

Every TMS creates the following metrics, known as request, error, and duration (RED) metrics. RED metrics appear when you select a service in the service map. See Scenario: Kai investigates the root cause of an error with the Splunk APM service map to learn more about using RED metrics in the service map.

Request rate
Error rate
Root cause error rate
p50, p90, and p99 latency

The measurement precision of Troubleshooting MetricSets is 10 seconds. Splunk APM reports quantiles from a distribution of metrics for each 10-second reporting window.

Use TMS within Splunk APM 🔗

TMS appear on the service map and in Tag Spotlight. Use TMS to filter the service map and create breakdowns across the values of a given indexed span tag or process.

See View dependencies among your services in the service map and Analyze service performance with Tag Spotlight.

TMS retention period 🔗

Splunk Observability Cloud retains TMS for the same amount of time as raw traces. By default, the retention period is 8 days.

For more details about Troubleshooting MetricSets, see Reference and best practices for span tags and Troubleshooting MetricSets.

Monitoring MetricSets 🔗

Monitoring MetricSets (MMS) are metric time series (MTS) that power the real-time monitoring capabilities in Splunk APM, including charts and dashboards. MMS power the APM landing page and the dashboard view. MMS are also the metrics that detectors monitor to generate alerts.

MMS are available for a specific endpoint or for the aggregate of all endpoints in a service.

Endpoint-level MMS reflect the activity of a single endpoint in a service, while service-level MMS aggregate the activity of all of the endpoints in the service. MMS are limited to spans where the span.kind has a value of SERVER or CONSUMER.

Spans might lack a kind value, or have a different kind value, in the following situations:

The span originates in self-initiating operations or inferred services
An error in instrumentation occurs.

In addition to the following default MMS, you can create custom MMS. See Create a Monitoring MetricSet with a custom dimension.

Available default MMS metrics and dimensions 🔗

MMS are available for the following APM components:

service.request
spans
inferred.services
traces
workflows (Workflow metrics are created by default when you create a Business Workflow. Custom MMS are not available for Business Workflows.)

Each MMS includes 6 metrics for each component. For histogram MMS, there is a single metric for each component. Use the histogram functions to access the specific histogram bucket you want to use.

For each metric, there is 1 metric time series (MTS) with responses sf_error: true or sf_error: false.

Description	MMS	Histogram MMS
Request count	`<component>.count`	`<component>` with a `count` function
Minimum request duration	`<component>.duration.ns.min`	`<component>` with a `min` function
Maximum request duration	`<component>.duration.ns.max`	`<component>` with a `max` function
Median request duration	`<component>.duration.ns.median`	`<component>` with a `median` function
Percentile request duration	`<component>.duration.ns.p90`	`<component>` with a `percentile` function and a percentile `value`
Percentile request duration	`<component>.duration.ns.p99`	`<component>` with a `percentile` function and a percentile `value`

Each MMS has a set of dimensions you can use to monitor and alert on service performance.

Service dimensions 🔗

sf_environment
deployment.environment - This dimension is only available for histogram MMS.
sf_service
service.name - This dimension is only available for histogram MMS.
sf_error

Inferred service dimensions 🔗

sf_service
service.name - This dimension is only available for histogram MMS.
sf_environment
deployment.environment - This dimension is only available for histogram MMS.
sf_error
sf.kind

Span dimensions 🔗

sf_environment
deployment.environment - This dimension is only available for histogram MMS.
sf_service
service.name - This dimension is only available for histogram MMS.
sf_operation
sf_kind
sf_error
sf_httpMethod, where relevant

Trace dimensions 🔗

Note

Trace dimensions are not supported for custom MMS.

sf_environment
deployment.environment - This dimension is only available for histogram MMS.
sf_service
service.name - This dimension is only available for histogram MMS.
sf_operation
sf_httpMethod
sf_error

Workflow dimensions 🔗

Workflow metrics and dimensions are created by default when you create a Business Workflow.

Note

Workflow dimensions are not supported for custom MMS.

sf_environment
deployment.environment - This dimension is only available for histogram MMS.
sf_workflow
sf_error

Use MMS within Splunk APM 🔗

Use MMS for alerting and real-time monitoring in Splunk APM. You can create charts, dashboards, and alerts based on Monitoring MetricSets.

Task	Documentation
Create charts	Create charts in Splunk Observability Cloud
Create dashboards	Create and customize dashboards
Create an alert	Configure detectors and alerts in Splunk APM
Monitor services in APM dashboards	Track service performance using dashboards in Splunk APM

MMS retention period 🔗

Splunk Observability Cloud stores MMS for 13 months by default.

Comparing Monitoring MetricSets and Troubleshooting MetricSets 🔗

Because endpoint-level and service-level MMS include a subset of the TMS metrics, you might notice that metric values for a service are different depending on the context in Splunk APM. This is because MMS are the basis of the dashboard view and MMS can only have a kind of SERVER or CONSUMER. In contrast, TMS are the basis of the troubleshooting and Tag Spotlight views and TMS aren’t restricted to specific metrics.

For example, values for checkout service metrics displayed in the host dashboard might be different from the metrics displayed in the service map because there are multiple span kind values associated with this service that the MMS that power the dashboard don’t monitor.

To compare MMS and TMS directly, restrict your TMS to endpoint-only data by filtering to a specific endpoint. You can also break down the service map by endpoint.

This page was last updated on Aug 14, 2024.

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