fix: Reliably show service and level in pattern sample drawer

[pulpdrew]

Summary

This PR fixes two issues with the event patterns sample table:

1. The table rendered an empty/undefined service for sources where the serviceNameExpression is not in the Primary Key (or where the Primary Key could not be accurately read by HyperDX due to distributed/merge table topologies).
2. The table rendered an empty/undefined level for trace sources

Root causes:

• For ServiceName: usePatterns never explicitly selected ServiceName in the first place, rather it just so happened that the ServiceName was added to the select by another optimization (appendSelectWithAdditionalKeys) which adds columns from the primary key.
• For Trace sources: usePatterns queries StatusCode, but the table did not read it, it was hardcoded to read SeverityText instead.

This fix updates the usePatterns query to explicitly query the correct columns under known alias names that are then referenced by those aliases in the PatternTable. This PR also includes E2E covering these cases.

Screenshots

Before:

Trace source level undefined

Missing Service:

After:

Trace source level defined

Service shown

Testing

• Open event patterns, test that the sample panel populates all columns for both log and trace sources.

If you'd like to test the service name case, use this as a source:

CREATE TABLE IF NOT EXISTS e2e_custom_service_name
(
  `Timestamp` DateTime64(9) CODEC(Delta(8), ZSTD(1)),
  `AppName` LowCardinality(String) CODEC(ZSTD(1)),
  `SeverityText` LowCardinality(String) CODEC(ZSTD(1)),
  `Body` String CODEC(ZSTD(1)),
  `LogAttributes` Map(LowCardinality(String), String) CODEC(ZSTD(1))
)
ENGINE = MergeTree
PARTITION BY toDate(Timestamp)
ORDER BY (toStartOfFiveMinutes(Timestamp), Timestamp)
TTL toDateTime(Timestamp) + toIntervalDay(30)
SETTINGS index_granularity = 8192, ttl_only_drop_parts = 1;

insert into e2e_custom_service_name values (now(), 'service!', 'info', 'hello', {});

References

Linear: Closes HDX-5274

[changeset-bot]

🦋 Changeset detected

Latest commit: 8c2e213

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 3 packages

Name	Type
@hyperdx/app	Patch
@hyperdx/api	Patch
@hyperdx/otel-collector	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[vercel]

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Project	Deployment	Actions	Updated
hyperdx-oss	Ready	Preview	Sep 2, 2026 11:18pm UTC
hyperdx-storybook	Ready	Preview	Sep 2, 2026 11:18pm UTC

[greptile-apps]

Greptile Summary

The PR explicitly selects service name and source-appropriate level values under stable aliases so event-pattern lists and sample drawers can display them reliably.

• Adds shared aliases for pattern service and level fields.
• Uses severity text for log levels and status code for trace levels.
• Updates the pattern drawer, list, and AI summary inputs to consume the aliases.
• Adds full-stack coverage and a log fixture whose service column is outside the primary key.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
packages/app/src/hooks/usePatterns.tsx	Explicitly projects service and source-appropriate level expressions under stable aliases and carries level into grouped pattern rows.
packages/app/src/components/PatternTable.tsx	Supplies service and level expressions to pattern sampling and displays the normalized level field.
packages/app/src/components/PatternSidePanel.tsx	Reads sample service and level values through stable aliases in the drawer table.
packages/app/src/components/AISummarizePatternButton.tsx	Builds AI summary input from the same normalized service and level aliases.
packages/app/src/components/DBRowTable.tsx	Uses the normalized pattern level for trend coloring and updates denoising queries to use the shared level-expression helper.
packages/app/src/source.ts	Adds a helper selecting severity text for logs and status code for traces.
packages/app/tests/e2e/features/search/event-patterns.spec.ts	Covers service-name rendering outside the primary key and trace status-code rendering as level.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart LR
  S[Selected log or trace source] --> E[getLevelExpression]
  S --> N[Service-name expression]
  E --> Q[Pattern sampling query]
  N --> Q
  Q --> A[Stable service and level aliases]
  A --> G[Grouped patterns]
  A --> D[Sample drawer]
  G --> T[Pattern list]
  A --> AI[AI summary input]

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_{Reviews (4): Last reviewed commit: "fix: Show level for traces in pattern si..." | Re-trigger Greptile}

[github-actions]

E2E Test Results

✅ All tests passed • 334 passed • 1 skipped • 1206s

Status	Count
✅ Passed	334
❌ Failed	0
⚠️ Flaky	3
⏭️ Skipped	1

Tests ran across 4 shards in parallel.

View full report →

[github-actions]

🔵 Tier 2 — Low Risk

Small, isolated change with no API route or data model modifications.

Why this tier:

• Standard feature/fix — introduces new logic or modifies core functionality

Review process: AI review + quick human skim (target: 5–15 min). Reviewer validates AI assessment and checks for domain-specific concerns.
SLA: Resolve within 4 business hours.

Stats

• Production files changed: 6
• Production lines changed: 167 (+ 280 in test files, excluded from tier calculation)
• Branch: cursor/fix-pattern-flyout-servicename-befe
• Author: pulpdrew

To override this classification, remove the review/tier-2 label and apply a different review/tier-* label. Manual overrides are preserved on subsequent pushes.

[github-actions]

Deep Review

✅ No critical issues found.

The rename from SEVERITY_TEXT_COLUMN_ALIAS/STATUS_CODE_COLUMN_ALIAS to SERVICE_NAME_COLUMN_ALIAS/LEVEL_COLUMN_ALIAS is clean: no dangling importers remain, the removed AISummarizePatternButton prop has its single call site updated, and the deleted ACCESSOR_MAP.severityText accessor (row.severityText ?? row.statusCode) is fully subsumed by getLevelExpression, which merges log severity and trace status code upstream so logLevelColor(row.original.level) preserves prior behavior. No other RawLogTable caller displays a severityText column. The trace-level fix is correct.

🟡 P2 -- recommended

• packages/app/src/source.ts:711 -- New exported getLevelExpression() has three behavior-carrying branches (log → severityTextExpression, trace → statusCodeExpression, else → '') but no unit test, and the log severity → Level branch is not exercised by either new E2E spec.
  • Fix: Add unit cases in source.test.ts covering all three branches plus undefined/empty-expression sources, and assert the Level column for the custom log source in the E2E flow.
  • _testing

🔵 P3 nitpicks (2)

• packages/app/tests/e2e/components/PatternSidePanelComponent.ts:790 -- Sample and pattern-list cells are located by hard-coded sibling-div indices (td > button > div.nth(N)) in both PatternSidePanelComponent and SearchPage.patternListLevelCell, silently coupling assertions to displayedColumns order in two components; a reorder shifts assertions to the wrong cell.
  • Fix: Add a stable per-column data-testid/data-column attribute on the rendered cell and locate by column identity instead of position.
  • _{testing, maintainability}
• packages/app/tests/e2e/utils/constants.ts:1226 -- Duplicated word in a newly added comment: "Log source with a a non-standard service name".
  • Fix: Remove the duplicate a.
  • _testing

---

Reviewers (4): testing, maintainability, kieran-typescript, previous-comments.

Testing gaps:

• getLevelExpression() log/trace/else branches are only exercised end-to-end, and the log severity → Level branch not at all — no direct unit coverage.
• No unit/integration test for the usePatterns SELECT alias rename; regression protection rests entirely on the two new E2E specs.
• Prior PR comments were all automated (changeset, Vercel, Greptile summary, E2E results) — no human review feedback to verify as addressed.

[github-actions]

PR Review

5 finding(s): 🔴 0 critical · 🟠 0 major · 🔵 5 minor

4 posted as inline comment(s) on the changed lines. 1 listed below.

Findings outside the changed lines

1 minor

• 🔵 packages/app/src/hooks/usePatterns.tsx:177 — Pattern query key omits the new level/service expressions, so the drawer can serve stale rows → queryKey: ['patterns', config, bodyValueExpression] does not include levelExpression or serviceNameExpression, yet both change the columns present on every cached sample row. Edit a source's serviceNameExpression (or severityTextExpression) in the source modal while the Event Patterns tab is open: config is unchanged, so the sample query refetches with the new SELECT but this query returns its cached rows, and the drawer keeps showing "undefined" for Service until something else invalidates the key. Add both expressions to the query key.

---

_{Severity is the reviewer's own estimate and is used for ordering, not filtering.}