PromQL querying

When you ingest OpenTelemetry metrics into CloudWatch via the Metrics endpoint, the hierarchical OTLP data model is flattened into PromQL-compatible labels. This section describes the label structure, the PromQL syntax for querying these labels, and the UTF-8 support in PromQL.

When using PromQL in CloudWatch, the @ prefix convention distinguishes OTLP-scoped labels from standard Prometheus labels. Fields within each scope use a double-@ prefix (for example, @resource.@schema_url), while attributes use a single-@ scope prefix, for example, @resource.service.name. Datapoint attributes also support bare (un-prefixed) access for backward compatibility with standard PromQL queries, for example, {"http.server.active_requests"} and {"@datapoint.@name"="http.server.active_requests"} are equivalent.

A PromQL expression is enclosed in curly braces, specifying the metric name and an optional set of label matchers. The following example selects all time series for the http.server.active_requests metric:

{"http.server.active_requests"}

The following example selects all time series for the metric http.server.active_requests where the OpenTelemetry resource attribute service.name equals myservice:

{"http.server.active_requests", "@resource.service.name"="myservice"}

You can combine multiple label matchers in a single query. The following example selects all time series for the http.server.active_requests metric where the OpenTelemetry resource attribute service.name equals myservice across all US regions:

{"http.server.active_requests",
 "@resource.service.name"="myservice",
 "@aws.region"=~"us-.*"}

The following example shows a range query. It calculates the average value of all datapoints within a specified time range for each time series:

avg_over_time(
  {"http.server.active_requests",
   "@resource.service.name"="myservice"}[5m]
)

The following table summarizes the prefix conventions for each OTLP scope:

Querying vended AWS metrics with PromQL

To be able to query vended AWS metrics in PromQL, you first need to enable OTel enrichment of vended metrics. See: AWS vended metrics in OpenTelemetry format.

After you enable OTel enrichment, vended AWS metrics become queryable via PromQL with additional labels. The metric name is the same as the original CloudWatch metric name, and the original CloudWatch dimensions are available as datapoint attributes. The following labels are available (the example below is for an EC2 instance):

The following example selects Invocations for a specific Lambda function:

{Invocations, FunctionName="my-api-handler"}

The following example selects Lambda Errors for all functions tagged with a specific team:

{Errors, "@instrumentation.@name"="cloudwatch.aws/lambda", "@aws.tag.Team"="backend"}

The following example computes the total Lambda Invocations grouped by team:

sum by ("@aws.tag.Team")(
    {Invocations, "@instrumentation.@name"="cloudwatch.aws/lambda"}
)

The following example selects all time series for the EC2 CPUUtilization metric. The usage of "@instrumentation.@name"="cloudwatch.aws/ec2" is to exclusively match CPUUtilization from EC2 and not from other AWS services such as Amazon Relational Database Service:

histogram_avg({CPUUtilization, "@instrumentation.@name"="cloudwatch.aws/ec2"})

Querying from Grafana

You can query CloudWatch PromQL data from Grafana by adding the Amazon Managed Service for Prometheus data source plugin and pointing it at the CloudWatch monitoring endpoint. SigV4 signing is built in to the plugin and is always enabled, so there is no toggle to turn on. The plugin is published at grafana.com/grafana/plugins/grafana-amazonprometheus-datasource/; install it from the Grafana plugins catalog before adding the data source. AMP plugin v3.0.0 requires Grafana >=11.6.11 <12 || >=12.0.10 <12.1 || >=12.1.7 <12.2 || >=12.2.5.

IAM prerequisites — the IAM principal whose credentials Grafana uses must have both cloudwatch:GetMetricData (required for instant and range queries) and cloudwatch:ListMetrics (required for series and label discovery). For details, see IAM permissions for PromQL.

To configure Grafana, complete the following steps.

Querying from Amazon Managed Grafana

You can query CloudWatch PromQL data from an Amazon Managed Grafana workspace by adding an Amazon Managed Service for Prometheus data source that points at the CloudWatch monitoring endpoint. This data source plugin signs requests with SigV4 using the workspace IAM role automatically; SigV4 is always enabled, with no toggle to configure. The plugin is available in Amazon Managed Grafana version 12 and later. For more information, see Connect to an Amazon Managed Service for Prometheus data source in the Amazon Managed Grafana User Guide.

IAM prerequisites — the Amazon Managed Grafana workspace IAM role must have both cloudwatch:GetMetricData (required for instant and range queries) and cloudwatch:ListMetrics (required for series and label discovery). For details, see IAM permissions for PromQL.

To configure the data source, complete the following steps.

Querying with MCP tools

The CloudWatch MCP Server provides Model Context Protocol (MCP) tools that let AI assistants and development tools query CloudWatch PromQL data on your behalf. The MCP tools handle authentication and request formatting automatically, so you can focus on writing PromQL queries rather than managing HTTP requests and SigV4 signing.

The following PromQL tools are available in the CloudWatch MCP Server:

For full details on parameters, configuration, and setup instructions, see Tools for CloudWatch PromQL in the CloudWatch MCP Server documentation.

Querying with the HTTP API

You can also query CloudWatch PromQL data programmatically by calling the Prometheus-compatible HTTP endpoints directly. Requests must be signed with AWS Signature Version 4 using monitoring as the service name.

The PromQL endpoint follows the pattern https://monitoring.AWS Region.amazonaws.com/api/v1/operation. For example, for the US East (N. Virginia) (us-east-1) Region, the endpoint for an instant query is https://monitoring.us-east-1.amazonaws.com/api/v1/query.

For the full API reference, including supported operations, request parameters, and response formats, see Prometheus-compatible APIs. For the list of AWS Regions where PromQL querying is available, see Supported AWS Regions. For the IAM actions required for each operation, see IAM permissions for PromQL.