[java-bigquerystorage] Accept an OpenTelemetry instance per stream writer instead of the cached GlobalOpenTelemetry

Open
  • Is something wrong?
#14,765 2 comments 0 reactions 0 assignees View on GitHub

Maintainers usually reply within 1 day

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
48/100
Issue type
Feature
Clarity
Clearly specified
Activity status
Active
Tech stack
java
Domain
observability

Research direction

Start with StreamWriter.Builder and the TelemetryMetrics and Singletons files linked in the issue; trace how each writer obtains its MeterProvider. Check the builders for JsonStreamWriter and SchemaAwareStreamWriter too, since the request asks for the same option there. Done means each builder can accept its own OpenTelemetry instance while an unset option retains the current global behavior.

Written by the indexing model from the issue text.

Description

Is your feature request related to a problem? Please describe.

The Storage Write client's OpenTelemetry metrics (StreamWriter.Builder.setEnableOpenTelemetry(true)) can only be sent to the process-wide GlobalOpenTelemetry.
TelemetryMetrics takes its MeterProvider from Singletons.getOpenTelemetry(), which caches GlobalOpenTelemetry.get() in a static field on first use and has no setter:

https://github.com/googleapis/google-cloud-java/blob/165f02ec20bc3db5eb8ca0b6ba09af6f6590be71/java-bigquerystorage/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/Singletons.java#L30-L36

https://github.com/googleapis/google-cloud-java/blob/165f02ec20bc3db5eb8ca0b6ba09af6f6590be71/java-bigquerystorage/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/TelemetryMetrics.java#L136-L139

This makes the metrics hard to use from a framework that hosts many writers in one JVM.
We maintain an Apache Flink connector for BigQuery (flink-gcp/flink-connector-gcp) and want to forward each writer's metrics into Flink's own metric system, which then exports them to whatever reporter the deployment uses (Prometheus, Datadog, OTLP).
With only the global instance:

  • several jobs or subtasks share one TaskManager JVM, so their writers cannot report to separate meter providers;
  • a library cannot call GlobalOpenTelemetry.set(...) without taking that global over from the application;
  • when the client is shaded into a connector jar, io.opentelemetry is relocated, so the relocated global is not one the application or a Java agent can set at all.

Describe the solution you'd like

An optional per-writer OpenTelemetry (or MeterProvider) on the writer builders, for example StreamWriter.Builder.setOpenTelemetry(OpenTelemetry), with the same setter on JsonStreamWriter.Builder and SchemaAwareStreamWriter.Builder.
When it is unset, the current GlobalOpenTelemetry behaviour would stay as it is.

Other clients in this repository already offer this:

  • Spanner: SpannerOptions.Builder.setClientMetricsProvider(MetricsProvider) (#13741).
  • Bigtable: BigtableDataSettings.Builder.setMetricsProvider(MetricsProvider), which accepts a CustomOpenTelemetryMetricsProvider.

Describe alternatives you've considered

  • GlobalOpenTelemetry.set(...) once per JVM: it cannot separate the writers of different jobs, and it does not reach a relocated copy of the client.
  • Reading the meters reflectively, or replacing Singletons: neither is a supported surface.

Additional context

  • Libraries-Bom: 26.90.0
    • google-cloud-bigquerystorage 3.35.0
  • The same code is on main at 165f02ec20bc3db5eb8ca0b6ba09af6f6590be71.
Dominant language
Java
Stars
2.1k
Forks
1.2k
Avg merge
2d 14h
Merged PRs (30d)
192

Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from googleapis/google-cloud-java

All issues in googleapis/google-cloud-java

Similar issues

More Java issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.