Your DevOps team deploys a critical microservice on Compute Engine instances with the Google Cloud Ops Agent. The Ops Agent is configured to ingest OpenTelemetry Protocol (OTLP) metrics using the Cloud Monitoring API mode (metrics_mode: googlecloudmonitoring). The application emits two cumulative counter metrics: workload.googleapis.com/custom/http_requests_total workload.googleapis.com/custom/http_errors_total You need to construct a PromQL-based alerting policy condition in Cloud Monitoring that triggers an incident whenever the 5-minute HTTP error rate exceeds 5% of total requests across the fleet. Which PromQL query correctly references these metrics according to Cloud Monitoring syntax conventions?

( sum(rate(workload_googleapis_com:custom_http_errors_total{monitored_resource="gce_instance"}[5m])) / sum(rate(workload_googleapis_com:custom_http_requests_total{monitored_resource="gce_instance"}[5m])) ) > 0.05: ### What Cloud Monitoring PromQL Metric Mapping Is When querying metrics ingested through the Cloud Monitoring API (`googlecloudmonitoring` ingestion mode) using **Prometheus Query Language (PromQL)**, metric names must follow specific conversion rules to be compatible with PromQL syntax. In Cloud Monitoring, the metric type is converted into a PromQL identifier, and monitored resources must be explicitly defined where applicable. ### How It Meets the Requirements 1. **Metric Name Transformation**: The standard Cloud Monitoring metric mapping rules mandate: * The **first forward slash (`/`)** in the metric type string is replaced with a **colon (`:`)**. * All other **special characters**, including periods (`.`) and subsequent forward slashes (`/`), are replaced with **underscores (`_`)**. * Therefore, `workload.googleapis.com/custom/http_errors_total` becomes `workload_googleapis_com:custom_http_errors_total`. 2. **Monitored Resource Filtering**: Because metrics ingested via the Cloud Monitoring API can theoretically attach to multiple resource types rather than defaulting to a single Prometheus target, PromQL queries must explicitly include the `{monitored_resource="gce_instance"}` label filter. 3. **Rate and Ratio Calculation**: Wrapping the cumulative counters in `rate(...[5m])` calculates the per-second rate of change over a 5-minute window, and computing the ratio with `/` compared against `> 0.05` enforces the 5% threshold. ### Key Advantages and Capabilities * **Syntactic Compliance**: Ensures query validation succeeds in the Cloud Monitoring PromQL editor. * **Fleet Aggregation**: Using `sum()` aggregates request and error rates across all matching VM instances. * **Precise Scoping**: Explicitly filtering on `monitored_resource="gce_instance"` avoids ambiguity in multi-resource environments. ### Why This Is Optimal This syntax precisely follows Google Cloud's documented mapping specification for non-Prometheus native custom metrics ingested via the Monitoring API, avoiding runtime query errors and missing data anomalies.

Promql Custom Metric Otlp Monitoring Api Alert | Professional Cloud DevOps Engineer

Promql Custom Metric Otlp Monitoring Api Alert

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Your DevOps team deploys a critical microservice on Compute Engine instances with the Google Cloud Ops Agent. The Ops Agent is configured to ingest OpenTelemetry Protocol (OTLP) metrics using the Cloud Monitoring API mode (metrics_mode: googlecloudmonitoring). The application emits two cumulative counter metrics:

workload.googleapis.com/custom/http_requests_total
workload.googleapis.com/custom/http_errors_total

You need to construct a PromQL-based alerting policy condition in Cloud Monitoring that triggers an incident whenever the 5-minute HTTP error rate exceeds 5% of total requests across the fleet.

Which PromQL query correctly references these metrics according to Cloud Monitoring syntax conventions?

( sum(rate(workload.googleapis.com:custom:http_errors_total[5m])) / sum(rate(workload.googleapis.com:custom:http_requests_total[5m])) ) > 0.05

( sum(rate(http_errors_total[5m])) / sum(rate(http_requests_total[5m])) ) > 0.05

( sum(rate(workload_googleapis_com:custom_http_errors_total{monitored_resource="gce_instance"}[5m])) / sum(rate(workload_googleapis_com:custom_http_requests_total{monitored_resource="gce_instance"}[5m])) ) > 0.05

( sum(rate(prometheus_googleapis_com:custom_http_errors_total_counter{monitored_resource="prometheus_target"}[5m])) / sum(rate(prometheus_googleapis_com:custom_http_requests_total_counter{monitored_resource="prometheus_target"}[5m])) ) > 0.05

Professional Cloud DevOps Engineer

Promql Custom Metric Otlp Monitoring Api Alert

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