Add blocking behavior for full processor queues

[arnabnandy7]

Fixes #5178

Changes

Adds configurable queue-full behavior for batch span and batch log record processors.

This introduces:

• onQueueFull with DROP and BLOCK behavior.
• blockOnQueueFullTimeoutMillis for bounded blocking when BLOCK is selected.
• Environment variables for both BSP and BLRP configuration:
  • OTEL_BSP_ON_QUEUE_FULL
  • OTEL_BSP_BLOCK_ON_QUEUE_FULL_TIMEOUT
  • OTEL_BLRP_ON_QUEUE_FULL
  • OTEL_BLRP_BLOCK_ON_QUEUE_FULL_TIMEOUT

The default behavior remains DROP, preserving existing behavior unless users opt into blocking.

• Related issues BatchSpanProcessor / BatchLogRecordProcessor: add opt-in blocking mode when queue is full #5178
• Related OTEP(s) # N/A
• Links to the prototypes (when adding or changing features) N/A
• CHANGELOG.md file updated for non-trivial changes
• Spec compliance matrix updated if necessary: N/A
• Declarative config data model is updated if SDK config surface is changed

[pellared]

The PR does not fulfill the contributing requirements: https://github.com/open-telemetry/opentelemetry-specification/blob/main/CONTRIBUTING.md#smaller-changes

[arnabnandy7]

The PR does not fulfill the contributing requirements: https://github.com/open-telemetry/opentelemetry-specification/blob/main/CONTRIBUTING.md#smaller-changes

@pellared should I wait until other high-value features are merged into it, then proceed?

[arnabnandy7]

@pellared, sorry to confuse you, I mean this PR was raised based on a change in #5178. If that alone doesn't qualify requirements, then should I need to add changes related to some other issues as well to make it bulky?

[cijothomas]

@pellared, sorry to confuse you, I mean this PR was raised based on a change in #5178. If that alone doesn't qualify requirements, then should I need to add changes related to some other issues as well to make it bulky?

The linked issue is not triaged and accepted. That is a pre-requisite.

[arnabnandy7]

The linked issue is not triaged and accepted. That is a pre-requisite.

@cijothomas @pellared thanks for the feedback. I'll wait for this issue to be moved till then I'll mark it as draft.

[pellared]

Moreover,

The PR description must include links to prototypes:

If the change adds or modifies SDK component configuration, the PR must link to a corresponding proposed change to the declarative configuration schema. These PRs should be approved and merged together.

Also this is a new configuration so it has to be marked as Development status.

[arnabnandy7]

@pellared, once it's accepted for triage, I'll ensure the missing components are adhered to.

[github-actions]

This PR was marked stale. It will be closed in 14 days without additional activity.

[opentelemetry-pr-dashboard]

Pull request dashboard status

Waiting on the author · refreshed 2026-08-20 15:49 UTC

Move out of draft to request review.

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