apollographql/router v1.59.1 on GitHub

🐛 Fixes

Fix transmitted header value for Datadog priority sampling resolution (PR #6017)

The router now transmits correct values of x-datadog-sampling-priority to downstream services.

Previously, an x-datadog-sampling-priority of -1 was incorrectly converted to 0 for downstream requests, and 2 was incorrectly converted to 1. When propagating to downstream services, this resulted in values of USER_REJECT being incorrectly transmitted as AUTO_REJECT.

Enable accurate Datadog APM metrics (PR #6017)

The router supports a new preview feature, the preview_datadog_agent_sampling option, to enable sending all spans to the Datadog Agent so APM metrics and views are accurate.

Previously, the sampler option in telemetry.exporters.tracing.common.sampler wasn't Datadog-aware. To get accurate Datadog APM metrics, all spans must be sent to the Datadog Agent with a psr or sampling.priority attribute set appropriately to record the sampling decision.

The preview_datadog_agent_sampling option enables accurate Datadog APM metrics. It should be used when exporting to the Datadog Agent, via OTLP or Datadog-native.

telemetry:
  exporters:
    tracing:
      common:
        # Only 10 percent of spans will be forwarded from the Datadog agent to Datadog. Experiment to find a value that is good for you!
        sampler: 0.1
        # Send all spans to the Datadog agent.
        preview_datadog_agent_sampling: true

Using these options can decrease your Datadog bill, because you will be sending only a percentage of spans from the Datadog Agent to Datadog.

Important

Users must enable preview_datadog_agent_sampling to get accurate APM metrics. Users that have been using recent versions of the router will have to modify their configuration to retain full APM metrics.
The router doesn't support in-agent ingestion control.
Configuring traces_per_second in the Datadog Agent won't dynamically adjust the router's sampling rate to meet the target rate.
Sending all spans to the Datadog Agent may require that you tweak the batch_processor settings in your exporter config. This applies to both OTLP and Datadog native exporters.

Learn more by reading the updated Datadog tracing documentation for more information on configuration options and their implications.

Fix non-parent sampling (PR #6481)

When the user specifies a non-parent sampler the router should ignore the information from upstream and use its own sampling rate.

The following configuration would not work correctly:

  exporters:
    tracing:
      common:
        service_name: router
        sampler: 0.00001
        parent_based_sampler: false

All spans are being sampled.
This is now fixed and the router will correctly ignore any upstream sampling decision.

By @BrynCooke in #6481