STO-533: Convert littdb to use otel

[cody-littley]

Describe your changes and provide context

LittDB's original metrics stack uses the prometheus APIs. Convert instead to using OTEL APIs.

Testing performed to validate your change

unit tests

[cursor]

PR Summary

Medium Risk
Switches LittDB metrics to the global OTel MeterProvider and changes startup/shutdown behavior for metrics export and serving, which could impact existing metrics names/labels and lifecycle in production.

Overview
LittDB metrics are migrated from Prometheus client types to OpenTelemetry instruments. LittDBMetrics and cache metrics now use OTel counters/gauges/histograms, record latencies in seconds with shared bucket boundaries, and tag per-table/per-cache series via OTel attributes.

Metrics wiring is simplified around a global OTel provider. buildMetrics now calls commonmetrics.SetupOtelPrometheus() and starts the /metrics HTTP server unconditionally when MetricsEnabled is true, returning a provider shutdown function that db.gatherMetrics invokes on teardown; config options for custom Prometheus registry/namespace are removed.

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The latest Buf updates on your PR. Results from workflow Buf / buf (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	May 19, 2026, 6:53 PM

[github-actions]

The latest Buf updates on your PR. Results from workflow Buf / buf (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	May 19, 2026, 6:53 PM

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[cursor]

Metrics HTTP server leaks after DB close

Medium Severity

The metrics HTTP server started by commonmetrics.StartMetricsServer is never shut down when db.Close() is called. The old code deferred d.metricsServer.Close() inside gatherMetrics, but the new code only defers d.metricsShutdown (the OTel provider.Shutdown), which flushes the meter provider without stopping the HTTP listener. The server only terminates when config.CTX is cancelled, and the default context is context.Background(), which is never cancelled. This leaks a goroutine and a bound TCP port after every Close() call.

Additional Locations (1)

• sei-db/db_engine/litt/littbuilder/db_impl.go#L282-L292

 

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[codecov]

Codecov Report

❌ Patch coverage is 6.66667% with 154 lines in your changes missing coverage. Please review.
✅ Project coverage is 58.98%. Comparing base (f87766f) to head (be9328d).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
sei-db/db_engine/litt/metrics/littdb_metrics.go	0.00%	107 Missing ⚠️
sei-db/db_engine/litt/util/cache_metrics.go	0.00%	31 Missing ⚠️
sei-db/db_engine/litt/littbuilder/build_utils.go	0.00%	9 Missing ⚠️
sei-db/db_engine/litt/littbuilder/db_impl.go	64.70%	6 Missing ⚠️
sei-db/db_engine/litt/littdb_config.go	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3466      +/-   ##
==========================================
+ Coverage   58.96%   58.98%   +0.02%     
==========================================
  Files        2185     2185              
  Lines      181869   181796      -73     
==========================================
- Hits       107240   107238       -2     
+ Misses      65024    64953      -71     
  Partials     9605     9605              

Flag	Coverage Δ
sei-chain-pr	42.77% <6.66%> (?)
sei-db	70.41% <ø> (-0.22%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
sei-db/db_engine/litt/littdb_config.go	55.55% <0.00%> (-0.70%)	⬇️
sei-db/db_engine/litt/littbuilder/db_impl.go	54.90% <64.70%> (-0.73%)	⬇️
sei-db/db_engine/litt/littbuilder/build_utils.go	50.00% <0.00%> (+5.70%)	⬆️
sei-db/db_engine/litt/util/cache_metrics.go	17.64% <0.00%> (+3.36%)	⬆️
sei-db/db_engine/litt/metrics/littdb_metrics.go	3.38% <0.00%> (+0.68%)	⬆️

... and 1 file with indirect coverage changes

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