Google Cloud Pub/Sub Telemetry

Implementation evidence

Google Cloud Pub/Sub Telemetry: from boundary to verified row

Use Google Cloud Pub/Sub Telemetry at a controlled application boundary, keep the event contract small, and verify a known outcome before building aggregate views.

1
Choose the outcome
Pub/Sub delivery reliability
2
Define the contract
message_id, message_type, topic, subscription, ordering_key_category, and release
3
Instrument the boundary
Pub/Sub can redeliver messages; keep the provider message ID and delivery attempt separate from the final business outcome.
4
Verify the evidence
Exercise a known fixture, then inspect pubsub_message_completed for one correctly typed terminal row.

Before you start

Prerequisites and boundaries

@google-cloud/pubsub and telemetry-sh initialized in a trusted publisher or subscriber
Stable topic, subscription, message type, and logical outcome definitions
An idempotent consumer and a documented acknowledgement or exactly-once policy

Delivery setup

Install and initialize server-side

Import telemetry-sh in server-only code and initialize it once with process.env.TELEMETRY_API_KEY. Keep ingestion credentials out of browser bundles, client-visible environment variables, source control, logs, and exception messages.

google-cloud-pubsub-install

npm installation

bash

npm install telemetry-sh

1Prepare one reusable server-side delivery client with bounded network behavior.
2Add the outcome event at the success, failure, retry, or timeout boundary.
3Send controlled fixtures and inspect the stored rows before enabling an alert.

Snippet

Start with one structured event

Add this shape where the workflow completes, fails, or retries. Then build the dashboard from real fields.

google-cloud-pubsub

Google Cloud Pub/Sub Telemetry event

javascript

await telemetry.log("pubsub_message_completed", {
  message_id: message.id,
  message_type: "account_export",
  topic: "account-exports",
  subscription: "account-export-worker",
  status: "success",
  delivery_attempt: message.deliveryAttempt ?? 1,
  wait_ms: Date.now() - Number(message.publishTime.getTime()),
  duration_ms: Math.round(performance.now() - startedAt),
  acknowledged: true,
  dead_lettered: false,
  service: "export-worker",
  release: process.env.APP_RELEASE,
});

Event contract

message_id, message_type, topic, subscription, ordering_key_category, and release

status, delivery_attempt, wait_ms, duration_ms, acknowledged, and error_type

dead_lettered, published_at, account_id, service, region, and environment

Implementation checkpoints

Checkpoint 1

Pub/Sub can redeliver messages; keep the provider message ID and delivery attempt separate from the final business outcome.

Checkpoint 2

Exactly-once delivery has subscription and regional constraints, so verify the actual configuration instead of inferring it from an acknowledgement call.

Checkpoint 3

Monitor provider backlog metrics beside application outcomes, and do not copy message data, attributes with private content, or unrestricted errors into events.

Verification

Prove the event arrived

Run this after exercising known success and failure cases. Replace the fallback table name if your final event contract differs from the snippet.

google-cloud-pubsub-verification

Google Cloud Pub/Sub Telemetry verification query

sql

SELECT *
FROM pubsub_message_completed
ORDER BY timestamp_utc DESC
LIMIT 20;

Confirm one terminal row per logical outcome, with the expected status, identifiers, units, and UTC time.

Inspect the inferred schema and verify that retries do not change field types or generate a new logical event ID.

Search the stored fields for credentials, raw payloads, prompts, private content, and unbounded error messages.

Exercise a provider timeout, ingestion rejection, and process shutdown before treating the dashboard as complete.

Implementation references

Review the event contract, data-safety guidance, and upstream primary documentation before enabling a new production path.

Background job monitoring Queue wait SQL Dead-letter growth SQL Pub/Sub exactly-once delivery Pub/Sub dead-letter topics Pub/Sub monitoring

Production boundary

Keep the outcome event small and recoverable

This pattern provides

A bounded, SQL-ready outcome beside the upstream workflow.
Stable fields for dashboards, alerts, and cross-event correlation.
A fixture-driven path for validating success, failure, retry, and timeout behavior.

This pattern does not provide

An OTLP exporter, automatic collection pipeline, or replacement for detailed traces and diagnostic logs.
Exactly-once delivery merely because the payload contains an event ID.
Permission to collect raw provider payloads, user content, credentials, or regulated data.

Delivery and idempotency Batching and shutdown Troubleshoot ingestion

Event schema starting points

Review the row grain, emit boundary, required types, privacy classes, example payload, and validation checklist before adapting a query or snippet to production.

Async reliability11 fields