fix(jaegermcp): Enforce response limits by abhay1999 · Pull Request #8242 · jaegertracing/jaeger

abhay1999 · 2026-03-24T16:17:09Z

What this PR does

MaxSpanDetailsPerRequest and MaxSearchResults were defined in the config but not consistently enforced across all MCP handlers. This PR wires the limits all the way through.

Changes

get_trace_errors.go

Continues iterating all spans to count total errors, but caps the Spans slice at maxSpanDetailsPerRequest
ErrorCount now reflects the true total error count, not the truncated slice length

get_trace_topology.go

Breaks collection loop once maxSpanDetailsPerRequest is reached

search_traces.go

Breaks aggregation loop once maxResults is reached
Fixed searchDepth clamping: guards with maxResults > 0 so unlimited (0) is not incorrectly clamped to 0

server.go

Wires MaxSpanDetailsPerRequest into NewGetTraceErrorsHandler and NewGetTraceTopologyHandler constructors

Tests added

TestGetTraceErrorsHandler_Handle_LimitEnforced — 5 error spans, limit 3, asserts ErrorCount==5 and len(Spans)<=3
TestGetTraceTopologyHandler_Handle_LimitEnforced — 6-span trace, limit 3, asserts len(Spans)<=3
TestSearchTracesHandler_Handle_LimitEnforced — 5 traces, limit 3, asserts len(Traces)<=3

Fixes #8118

MaxSpanDetailsPerRequest and MaxSearchResults were defined in the config but not consistently enforced across all MCP handlers: - get_trace_errors: collected all error spans without any cap; now continues iterating to count total errors but caps Spans slice at maxSpanDetailsPerRequest. ErrorCount reflects the true total. - get_trace_topology: collected all spans without any cap; now breaks once maxSpanDetailsPerRequest is reached - search_traces: aggregation loop had no hard cap; now breaks once maxResults is reached. Fixed searchDepth clamping to guard with maxResults > 0 so unlimited (0) is not incorrectly clamped to 0. - server.go: wire MaxSpanDetailsPerRequest into NewGetTraceErrorsHandler and NewGetTraceTopologyHandler constructors Tests added: - TestGetTraceErrorsHandler_Handle_LimitEnforced: 5 error spans, limit 3, asserts ErrorCount==5 and len(Spans)<=3 - TestGetTraceTopologyHandler_Handle_LimitEnforced: 6-span trace, limit 3, asserts len(Spans)<=3 - TestSearchTracesHandler_Handle_LimitEnforced: 5 traces, limit 3, asserts len(Traces)<=3 Fixes jaegertracing#8118 Signed-off-by: abhay1999 <abhaychaurasiya19@gmail.com>

Copilot

Pull request overview

This PR enforces configured response-size limits in the Jaeger MCP extension handlers so MCP tool outputs stay bounded and consistent with MaxSpanDetailsPerRequest / MaxSearchResults.

Changes:

Wire MaxSpanDetailsPerRequest into get_trace_errors and get_trace_topology handlers and enforce span caps.
Enforce MaxSearchResults in search_traces result aggregation and fix searchDepth clamping for the “unlimited” (0) case.
Add unit tests covering the new limit enforcement behavior.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
cmd/jaeger/internal/extension/jaegermcp/server.go	Pass configured span limits into newly updated handler constructors.
cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_errors.go	Track total error count while capping collected span details.
cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_errors_test.go	Add test for `get_trace_errors` truncation + total error count.
cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_topology.go	Add span-detail limit to handler and stop collecting spans after cap.
cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_topology_test.go	Add test ensuring topology output is capped by the limit.
cmd/jaeger/internal/extension/jaegermcp/internal/handlers/search_traces.go	Stop adding summaries after `maxResults`; guard `searchDepth` clamp when `maxResults==0`.
cmd/jaeger/internal/extension/jaegermcp/internal/handlers/search_traces_test.go	Add test ensuring search results are capped.

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cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_topology.go

cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_errors.go

cmd/jaeger/internal/extension/jaegermcp/internal/handlers/search_traces_test.go

cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_topology_test.go

cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_errors_test.go

codecov · 2026-03-24T16:36:12Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.65%. Comparing base (4cf3087) to head (b7d1c8a).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8242   +/-   ##
=======================================
  Coverage   95.65%   95.65%           
=======================================
  Files         319      319           
  Lines       16795    16804    +9     
=======================================
+ Hits        16065    16074    +9     
  Misses        577      577           
  Partials      153      153

Flag	Coverage Δ
badger_direct	`9.06% <ø> (ø)`
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unittests	`94.34% <100.00%> (+<0.01%)`	⬆️

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- Replace AggregateTraces with AggregateTracesWithLimit in get_trace_errors and get_trace_topology handlers so that memory is bounded at aggregation time, not just at response time. - Tighten limit-enforcement tests to use assert.Equal instead of assert.LessOrEqual, ensuring the handler returns exactly maxSpanDetailsPerRequest spans when the trace exceeds the limit. Signed-off-by: abhay1999 <abhaychaurasiya19@gmail.com> Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Replace assert.Equal(t, N, len(x)) with assert.Len(t, x, N) in all three limit-enforcement tests as required by the testifylint linter. Signed-off-by: abhay1999 <abhaychaurasiya19@gmail.com> Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Copilot

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

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cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_errors.go

cmd/jaeger/internal/extension/jaegermcp/internal/handlers/get_trace_errors_test.go

cmd/jaeger/internal/extension/jaegermcp/internal/handlers/search_traces.go

- Revert get_trace_errors to AggregateTraces (unbounded) so ErrorCount reflects the true total of error spans in the full trace; Spans is already capped inside the iteration loop via maxSpanDetailsPerRequest. - Update test to assert ErrorCount==5 (full trace) and len(Spans)==3 (capped), matching the intended split semantics. - Remove the redundant `h.maxResults > 0` guard in search_traces since config validation already enforces MaxSearchResults in [1, 1000]. Signed-off-by: abhay1999 <abhaychaurasiya19@gmail.com>

When MaxSearchResults is 0 (unlimited), the searchDepth clamp `if searchDepth > h.maxResults` evaluates as `10 > 0 == true` and sets searchDepth to 0. This causes the storage query to return no results even though the config intends no limit. Guard the clamp with `h.maxResults > 0` so that an unlimited config preserves the requested or default search depth. Found while reviewing jaegertracing#8242. Signed-off-by: Roshan <rosh.s568@gmail.com> Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> Signed-off-by: Roshan <rosh.s568@gmail.com>

abhay1999 requested a review from a team as a code owner March 24, 2026 16:17

Copilot AI review requested due to automatic review settings March 24, 2026 16:17

Copilot started reviewing on behalf of abhay1999 March 24, 2026 16:17 View session

Merge branch 'main' into fix/mcp-enforce-limits

53fb7f7

Copilot AI reviewed Mar 24, 2026

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abhay1999 and others added 2 commits March 25, 2026 08:15

Copilot AI review requested due to automatic review settings March 25, 2026 02:54

Copilot started reviewing on behalf of abhay1999 March 25, 2026 02:55 View session

Merge branch 'main' into fix/mcp-enforce-limits

0404c9d

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abhay1999 mentioned this pull request Mar 25, 2026

[Feature]: GenAI integration with Jaeger #7827

Open

yurishkuro approved these changes Mar 26, 2026

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yurishkuro added the changelog:experimental Change to an experimental part of the code label Mar 26, 2026

yurishkuro changed the title ~~fix(jaegermcp): enforce response limits and add test coverage~~ fix(jaegermcp): Enforce response limits and add test coverage Mar 26, 2026

yurishkuro changed the title ~~fix(jaegermcp): Enforce response limits and add test coverage~~ fix(jaegermcp): Enforce response limits Mar 26, 2026

yurishkuro merged commit 8a4c314 into jaegertracing:main Mar 26, 2026
72 of 73 checks passed

abhay1999 deleted the fix/mcp-enforce-limits branch March 26, 2026 14:46

lopster568 mentioned this pull request Mar 26, 2026

[jaegermcp] Fix searchDepth clamped to zero when maxResults is unlimited #8250

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fix(jaegermcp): Enforce response limits#8242

fix(jaegermcp): Enforce response limits#8242
yurishkuro merged 6 commits intojaegertracing:mainfrom
abhay1999:fix/mcp-enforce-limits

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