OpenTelemetry Collector: Debugging, Operations, and Scaling
Extensions zPages
zPages extension for OpenTelemetry Collector offering in-process HTTP debug pages for service, pipeline, extension, feature gates, and trace diagnostics
zPages provides quick, built-in, in-process diagnostic visibility for the OpenTelemetry Collector. Originally developed for gRPC at Google, zPages moved into OpenCensus and later into OpenTelemetry. Its core value remains: lightweight diagnostics served from inside the Collector process with no external backend required. In the Collector, zPages runs as an extension and exposes a small HTTP server with several helpful debug pages.Enabling the zPages extension adds a diagnostics endpoint that listens inside the Collector process. Add the extension under the extensions section of your Collector configuration:
extensions: zpages: endpoint: "0.0.0.0:55679"
zPages exposes in-process diagnostic web pages (servicez, pipelinez, extensionz, featurez, tracez) for quick operational visibility. It is not a metrics scrape endpoint like Prometheus. See the OpenTelemetry Collector documentation for extension configuration and security recommendations.
Key zPages you’ll commonly use:
Page
Purpose
Typical path
servicez
Snapshot of the running Collector: build, version, runtime, OS, architecture
/debug/servicez
pipelinez
Effective pipelines assembled by the Collector (receivers → processors → exporters)
/debug/pipelinez
extensionz
List of enabled extensions (health_check, pprof, zpages, etc.)
/debug/extensionz
featurez
Feature gates and their states (alpha/beta/stable)
/debug/featurez
tracez
Live spans and latency bucket samples produced inside the Collector
/debug/tracez
Service snapshot (servicez)
The servicez page gives a concise snapshot of the Collector build and runtime — useful to confirm the exact binary and runtime environment you’re troubleshooting.
Pipelines (pipelinez)
The pipelinez page shows how the Collector assembled each pipeline for traces, metrics, and logs. Instead of parsing the config file, you can inspect the effective pipeline order — receivers, processors (memory_limiter, attributes, batch, etc.), and exporters — which is especially useful for troubleshooting ordering or missing components.
Extensions (extensionz)
The extensionz page lists currently enabled extensions (for example: health_check, pprof, zpages). Use this to confirm which auxiliary endpoints and runtime capabilities are active on your Collector instance.
Feature gates (featurez)
Feature gates allow toggling experimental, deprecated, or upcoming features at runtime. The featurez page shows each gate’s description, release stage (alpha/beta/stable), and current state — helpful when verifying whether an experimental feature is enabled in your running Collector.
Trace sampling and latency (tracez)
The tracez page groups spans generated inside the Collector by latency buckets so you can quickly spot slow components. Latency buckets (for example, >10s) highlight problematic spans, making it easier to find exporter delays, retry behavior, or upstream errors. Trace samples show when the Collector sent, retried, or waited — invaluable for debugging delivery or exporter issues.
Do not expose zPages to untrusted networks. zPages reveals internal diagnostics that could disclose configuration and runtime details. Run the extension on localhost or protect it with network policies and authentication if accessible from broader networks.
