Skip to content

feat: exporter prometheus_client /metrics (JEP-0013 Phase 2) - #934

Merged
mangelajo merged 16 commits into
jumpstarter-dev:mainfrom
RoddieKieley:jep-0013-phase2-exporter-metrics
Aug 25, 2026
Merged

feat: exporter prometheus_client /metrics (JEP-0013 Phase 2)#934
mangelajo merged 16 commits into
jumpstarter-dev:mainfrom
RoddieKieley:jep-0013-phase2-exporter-metrics

Conversation

@RoddieKieley

Copy link
Copy Markdown
Contributor
  • Add exporter-local prometheus_client registry with JEP-named series: jumpstarter_operations_total, jumpstarter_operation_duration_seconds, jumpstarter_operation_errors_total, jumpstarter_stream_bytes_total, jumpstarter_active_sessions, plus exemplars (client, lease_id).
  • Expose HTTP GET /metrics on the exporter process for lab/dev scrape (same registry Phase 3 will later reverse-scrape via MetricsStream).
  • Minimal core-path wiring so series increment under test; full per-driver telemetry architecture remains Phase 4.

@coderabbitai

coderabbitai Bot commented Jul 30, 2026

Copy link
Copy Markdown
Contributor

Review Change Stack

Note

Reviews paused

It looks like this branch is under active development. To avoid overwhelming you with review comments due to an influx of new commits, CodeRabbit has automatically paused this review. You can configure this behavior by changing the reviews.auto_review.auto_pause_after_reviewed_commits setting.

Use the following commands to manage reviews:

  • @coderabbitai resume to resume automatic reviews.
  • @coderabbitai review to trigger a single review.

Use the checkboxes below for quick actions:

  • ▶️ Resume reviews
  • 🔍 Trigger review

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info
⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 643cea3a-48f4-4e37-a006-03476029dddf

📥 Commits

Reviewing files that changed from the base of the PR and between b29c345 and 21dd350.

📒 Files selected for processing (2)
  • python/packages/jumpstarter/jumpstarter/driver/base.py
  • python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py
🚧 Files skipped from review as they are similar to previous changes (2)
  • python/packages/jumpstarter/jumpstarter/driver/base.py
  • python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py

📝 Walkthrough

Walkthrough

The exporter adds a local Prometheus registry, an HTTP metrics server, driver and stream instrumentation, active-session tracking, and configurable CLI bind-address propagation.

Changes

Exporter metrics

Layer / File(s) Summary
Metrics registry and HTTP server
python/packages/jumpstarter/jumpstarter/metrics/*, python/packages/jumpstarter/pyproject.toml
Adds metrics for operations, errors, durations, streams, sessions, and exemplars. Serves OpenMetrics data at /metrics with configurable bind behavior.
Driver, session, and stream instrumentation
python/packages/jumpstarter/jumpstarter/driver/base.py, python/packages/jumpstarter/jumpstarter/exporter/session.py, python/packages/jumpstarter/jumpstarter/streams/common.py, python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py
Records driver outcomes and durations, classifies failures, tracks active sessions, and records directional stream bytes. Tests cover registry behavior and integration wiring.
Metrics bind configuration
python/packages/jumpstarter-cli/jumpstarter_cli/run.py
Adds --metrics-bind-address, defaults it to :0, supports 0 to disable metrics, and forwards it to the child process.

Estimated code review effort: 4 (Complex) | ~45 minutes

Merge Risk: ⚪ Minimal · up to 21dd3

The metrics exporter change has no actionable merge-blocking risk identified at the current head and is merge-ready after normal checks and review.

Sequence Diagram(s)

sequenceDiagram
  participant CLI as run command
  participant Child as exporter child
  participant Server as metrics HTTP server
  participant Registry as MetricsRegistry
  participant Driver as driver handler
  CLI->>Child: pass metrics_bind_address
  Child->>Server: start metrics server
  Server->>Registry: expose /metrics
  Driver->>Registry: record operations and stream bytes
  Registry-->>Server: return OpenMetrics data
Loading

Poem

A rabbit tracks each byte in flight,
And marks each driver call just right.
The metrics server starts on cue,
With ephemeral ports when set to :0.
Sessions rise and fall in view.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name Status Explanation Resolution
Docstring Coverage ⚠️ Warning Docstring coverage is 31.82% which is insufficient. The required threshold is 80.00%. Write docstrings for the functions missing them to satisfy the coverage threshold.
✅ Passed checks (4 passed)
Check name Status Explanation
Title check ✅ Passed The title clearly identifies the exporter Prometheus metrics feature and its JEP-0013 phase.
Description check ✅ Passed The description directly explains the exporter-local metrics registry, HTTP endpoint, exemplars, and core-path wiring.
Linked Issues check ✅ Passed Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check ✅ Passed Check skipped because no linked issues were found for this pull request.
✨ Finishing Touches
🧪 Generate unit tests (beta)
  • Create PR with unit tests

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

Comment @coderabbitai help to get the list of available commands.

Comment thread python/packages/jumpstarter/jumpstarter/metrics/__init__.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/exporter/session.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py
Comment thread python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py

@coderabbitai coderabbitai Bot left a comment

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)
python/packages/jumpstarter/jumpstarter/driver/base.py (1)

161-173: 🗄️ Data Integrity & Integration | 🟠 Major | ⚡ Quick win

Record unary success after response serialization.

encode_value(result) can raise after _record_operation_metrics(..., result="success") records success, then the generic handler records the same RPC as result="failure". Build the DriverCallResponse before recording success.

🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@python/packages/jumpstarter/jumpstarter/driver/base.py` around lines 161 -
173, The unary operation handler currently records success before response
serialization can fail. In the surrounding operation flow, construct the
DriverCallResponse and run encode_value(result) before calling
_record_operation_metrics with result="success"; keep the success log and return
after serialization succeeds so encoding failures are handled only as failures.
🤖 Prompt for all review comments with AI agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Outside diff comments:
In `@python/packages/jumpstarter/jumpstarter/driver/base.py`:
- Around line 161-173: The unary operation handler currently records success
before response serialization can fail. In the surrounding operation flow,
construct the DriverCallResponse and run encode_value(result) before calling
_record_operation_metrics with result="success"; keep the success log and return
after serialization succeeds so encoding failures are handled only as failures.

ℹ️ Review info
⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 75605a6c-9f92-4070-b4a6-707a6f3fe110

📥 Commits

Reviewing files that changed from the base of the PR and between 7fb0364 and 1c23b95.

⛔ Files ignored due to path filters (1)
  • python/uv.lock is excluded by !**/*.lock
📒 Files selected for processing (9)
  • python/packages/jumpstarter-cli/jumpstarter_cli/run.py
  • python/packages/jumpstarter/jumpstarter/driver/base.py
  • python/packages/jumpstarter/jumpstarter/exporter/session.py
  • python/packages/jumpstarter/jumpstarter/metrics/__init__.py
  • python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py
  • python/packages/jumpstarter/jumpstarter/metrics/registry.py
  • python/packages/jumpstarter/jumpstarter/metrics/server.py
  • python/packages/jumpstarter/jumpstarter/streams/common.py
  • python/packages/jumpstarter/pyproject.toml

@RoddieKieley
RoddieKieley requested a review from raballew August 11, 2026 23:06
@bennyz
bennyz requested a review from bkhizgiy August 12, 2026 13:22

@coderabbitai coderabbitai Bot left a comment

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actionable comments posted: 1

🧹 Nitpick comments (1)
python/packages/jumpstarter-cli/jumpstarter_cli/run.py (1)

325-345: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

Add or verify command-level coverage for the new option.

The supplied tests cover start_metrics_server, but not the run command boundary. If no command-level test exists, cover the default :0, the disable value 0, and forwarding into _serve_with_exc_handling.

As per coding guidelines, Python test files must provide comprehensive package test coverage.

🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@python/packages/jumpstarter-cli/jumpstarter_cli/run.py` around lines 325 -
345, Add command-level tests for the `run` command that verify the default
`metrics_bind_address` value `:0`, the disable value `0`, and forwarding the
selected value into `_serve_with_exc_handling`. Reuse the existing CLI test
fixtures and preserve coverage of the `run` boundary in addition to
`start_metrics_server`.

Source: Coding guidelines

🤖 Prompt for all review comments with AI agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py`:
- Around line 210-217: Update start_metrics_server and
test_metrics_server_ephemeral_bind_returns_concrete_port so the test receives a
shutdown handle along with the address, then invoke that handle in a finally
block surrounding the URL request and assertions to close the listening socket
and background thread.

---

Nitpick comments:
In `@python/packages/jumpstarter-cli/jumpstarter_cli/run.py`:
- Around line 325-345: Add command-level tests for the `run` command that verify
the default `metrics_bind_address` value `:0`, the disable value `0`, and
forwarding the selected value into `_serve_with_exc_handling`. Reuse the
existing CLI test fixtures and preserve coverage of the `run` boundary in
addition to `start_metrics_server`.
🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

  • Push a commit to this branch (recommended)
  • Create a new PR with the fixes

ℹ️ Review info
⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: c82536c3-1000-4fc8-915c-1965ef93b839

📥 Commits

Reviewing files that changed from the base of the PR and between 8215b9f and b29c345.

📒 Files selected for processing (3)
  • python/packages/jumpstarter-cli/jumpstarter_cli/run.py
  • python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py
  • python/packages/jumpstarter/jumpstarter/metrics/server.py
🚧 Files skipped from review as they are similar to previous changes (1)
  • python/packages/jumpstarter/jumpstarter/metrics/server.py

Comment thread python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/server.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/__init__.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/server.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/server.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/streams/common.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py Outdated
@RoddieKieley
RoddieKieley requested a review from raballew August 14, 2026 15:35

@mangelajo mangelajo left a comment

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Review Summary — PR #934: Exporter Prometheus metrics (JEP-0013 Phase 2)

This PR adds exporter-local Prometheus metrics with a prometheus_client registry, an HTTP /metrics endpoint, and instrumentation of the DriverCall/StreamingDriverCall/Stream code paths. Previous review feedback (26 threads from raballew and CodeRabbit) has been thoroughly addressed.

JEP-0013 Compliance Assessment

What Phase 2 should deliver per the JEP:

  1. /metrics scrape endpoints on Controller and Router (covered by PR #933)
  2. Exporter-local prometheus_client counters/histograms/gauges with driver_type
  3. Prometheus exemplars for client, lease_id, trace_id (when present)

Metric series implemented vs. JEP specification:

JEP Series Implemented Notes
jumpstarter_operations_total Yes Labels: exporter, operation, result, driver_type — matches JEP
jumpstarter_operation_duration_seconds Yes Histogram with default buckets — matches JEP
jumpstarter_operation_errors_total Yes Labels include error_type — matches JEP
jumpstarter_stream_bytes_total Yes Labels: exporter, driver_type, direction — matches JEP
jumpstarter_active_sessions Yes Gauge with exporter label — matches JEP
jumpstarter_lease_acquisitions_total No Controller-side metric — not in scope for this PR
jumpstarter_telemetry_dropped_total No Phase 3 (Telemetry service) — correctly deferred
jumpstarter_scrape_timeouts_total No Phase 3 (Telemetry service) — correctly deferred

Gaps / deviations from JEP:

  1. trace_id exemplar: JEP lists trace_id as an exemplar key. This PR only implements client and lease_id. Likely a Phase 3+ concern.
  2. driver_type unbounded: JEP specifies a driverTypeEnum allowlist with remap to "other". The implementation accepts any string. The codebase already has 6 driver types outside the JEP's predefined set (automotive, bluetooth, gpio, debug, shell, testing). No remapping is done.
  3. operation unbounded: The label comes from @export method names. Bounded per-process by loaded drivers but not validated against an allowlist.

All three gaps are documented in inline comments. None are blockers for Phase 2.

What looks good

  • Isolation from RPC path: _record_operation_metrics wraps all metrics calls in try/except, ensuring metrics failures never discard gRPC responses or change abort status codes. This is tested by test_driver_call_succeeds_when_metrics_recording_raises.
  • AbortError bypass: The grpc.aio.AbortError catch before the generic except Exception prevents cardinality explosion from client-controlled invalid method names. Tested by test_unknown_driver_method_does_not_record_operation_metric.
  • Encode-before-record: Success metrics are recorded only after the response is encoded, so serialization failures correctly count as failures.
  • Dedicated registry: Uses a separate CollectorRegistry (not prometheus_client.REGISTRY), avoiding pollution from/to default Go-style process metrics. This is the right choice for the exporter.
  • Non-fatal server binding: Metrics server bind failures log a warning and return ("", None), so the exporter continues operating without metrics.
  • Error type consolidation: The _DRIVER_CALL_ERRORS table replaces duplicated exception handling blocks in DriverCall and StreamingDriverCall, reducing code from ~90 lines to ~35 — a nice refactor.
  • Stream metrics: copy_stream captures metrics context once before the loop, not per-chunk, avoiding repeated structlog lookups in the hot path.
  • Test coverage: 400+ lines of tests covering the registry, server lifecycle, driver error mapping, exemplars, cardinality protection, and graceful degradation.

Findings (see inline comments)

  1. driver_type unbounded — No remapping of unknown driver types to "other" as the JEP specifies. Not a blocker but worth tracking.
  2. operation label unbounded — Bounded in practice by loaded drivers but not documented/validated.
  3. error_type type safety_record_operation_metrics accepts str | None rather than ErrorType | None, so the Literal types can't catch typos.
  4. Stream metrics hot-path — Per-chunk Counter.inc() could add overhead for high-throughput streams; monitor and batch if needed.
  5. Ephemeral port default--metrics-bind-address defaults to :0 (always enabled, random port). Question about intent for controller-mode exporters.
  6. trace_id exemplar missing — JEP includes it; presumably Phase 3.

No blocking issues. The implementation is well-aligned with JEP-0013 Phase 2 scope.


AI generated, human reviewed/modified.

Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py
Comment thread python/packages/jumpstarter/jumpstarter/streams/common.py
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py
Comment thread python/packages/jumpstarter/jumpstarter/metrics/server.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py
Comment thread python/packages/jumpstarter-cli/jumpstarter_cli/run.py Outdated
Comment thread python/packages/jumpstarter-cli/jumpstarter_cli/run.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/registry.py
Comment thread python/packages/jumpstarter/jumpstarter/streams/common.py
RoddieKieley and others added 12 commits August 19, 2026 18:37
- Add exporter-local `prometheus_client` registry with JEP-named series: `jumpstarter_operations_total`, `jumpstarter_operation_duration_seconds`, `jumpstarter_operation_errors_total`, `jumpstarter_stream_bytes_total`, `jumpstarter_active_sessions`, plus exemplars (`client`, `lease_id`).
- Expose HTTP `GET /metrics` on the exporter process for lab/dev scrape (same registry Phase 3 will later reverse-scrape via MetricsStream).
- Minimal core-path wiring so series increment under test; full per-driver telemetry architecture remains Phase 4.
Re-raise grpc AbortError before generic handlers to avoid client-controlled
operation label cardinality, tighten bounded metric label types, default
metrics bind host to loopback, log session metric decrements on failure, and
expand exporter metrics unit coverage.
Avoid repeated exporter/exemplar context lookups inside the copy_stream
loop now that metrics helpers are imported at module level.
Build DriverCallResponse (including encode_value) before recording success
so serialization failures are counted only as failures, with a regression test.

Co-authored-by: Cursor <cursoragent@cursor.com>
Default jmp run --metrics-bind-address to :0 so concurrent exporters do not
collide on 8080, and treat metrics listen bind errors as non-fatal so the
exporter continues without /metrics when a fixed port is already taken.
Stop the metrics HTTP server from tests and jmp run so listen sockets
are not leaked after exporter exit.
Parse failures (ValueError) now share the bind-failure path so a bad
--metrics-bind-address cannot crash the exporter.

Co-authored-by: Cursor <cursoragent@cursor.com>
Avoid a race where the asyncio path and metrics HTTP thread each create
a MetricsRegistry and discard counters from the first instance.

Co-authored-by: Cursor <cursoragent@cursor.com>
Clear the exporter correlation field after decrementing active sessions
so it does not leak into later sessions or logs.

Co-authored-by: Cursor <cursoragent@cursor.com>
Centralize DriverCall/StreamingDriverCall error mapping, move
reset_registry_for_tests to metrics/_testing, restore log_message(format=),
hoist session/stream imports, tighten exemplar regex asserts, add metrics
HTTP request timeout and backlog limits, and rename
inc_active_sessions to adjust_active_sessions.

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
@RoddieKieley
RoddieKieley force-pushed the jep-0013-phase2-exporter-metrics branch from e6fca45 to 35674c9 Compare August 19, 2026 21:10
Co-authored-by: Cursor <cursoragent@cursor.com>
Comment thread python/packages/jumpstarter/jumpstarter/metrics/metrics_test.py
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/metrics/server.py Outdated
Comment thread python/packages/jumpstarter/jumpstarter/driver/base.py Outdated
RoddieKieley and others added 2 commits August 23, 2026 15:57
Narrow _record_operation_metrics to OperationResult/ErrorType, set the
metrics HTTP backlog before listen(), annotate ServicerContext on
_handle_driver_exception, and cover unary client cancel so hang does
not create operation or error series.

Co-authored-by: Cursor <cursoragent@cursor.com>
Address mangelajo review items on PR jumpstarter-dev#934: bind/parse failures now raise
instead of soft-failing without /metrics, and jmp run always starts the
local HTTP metrics server on ephemeral loopback (:0) with no public
--metrics-bind-address option (Phase 3 will gate/reverse-scrape).

Co-authored-by: Cursor <cursoragent@cursor.com>
@RoddieKieley
RoddieKieley requested a review from mangelajo August 23, 2026 19:12
@RoddieKieley
RoddieKieley requested a review from raballew August 23, 2026 19:12

@raballew raballew left a comment

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Only one nit left. I leave it up to you to fix it, if you think it adds value.

Comment thread python/packages/jumpstarter/jumpstarter/streams/common.py
Cover the chunk-copy path so jumpstarter_stream_bytes_total is no longer
only incremented via registry helpers, addressing the remaining jumpstarter-dev#934 nit.

Co-authored-by: Cursor <cursoragent@cursor.com>
@RoddieKieley

Copy link
Copy Markdown
Contributor Author

@mangelajo I addressed the last nit there from @raballew after his original approval which I think still stands. We need CI go ahead as well as a pass by you I think - anything else outstanding?

@mangelajo
mangelajo enabled auto-merge August 25, 2026 08:21
@mangelajo
mangelajo added this pull request to the merge queue Aug 25, 2026
Merged via the queue into jumpstarter-dev:main with commit 63ecb54 Aug 25, 2026
28 checks passed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

4 participants