feat(QTDI-2030): Add health and readiness endpoints to component-server by undx · Pull Request #1245 · Talend/component-runtime

undx · 2026-06-23T14:24:49Z

Summary

Implements two new Kubernetes-style probe endpoints for the component-server, resolving recurring cluster restart failures in Talend Cloud (AU/AP incidents).

The existing /environment endpoint was insufficient because it returns 200 even when the server cannot process requests. This PR introduces:

GET /api/v1/health (liveness probe) — checks heap memory availability, component index validity, and Vault connectivity. Returns 503 {"status":"DOWN","cause":"..."\} if any check fails, triggering a pod restart.
GET /api/v1/readiness (readiness probe) — checks that the component index has finished loading. Returns 503 while the index is being built, preventing premature traffic routing.

Key design decisions:

Memory threshold is configurable via talend.server.health.memory.threshold (default: 10%)
Runtime.maxMemory() == Long.MAX_VALUE guard prevents false DOWN on unbounded heap
Vault check is skipped when vaultUrl == "no-vault" (standalone mode)
catch (Throwable t) in component index check is intentional — required to catch OOME (documented in PR comment below)

Jira: QTDI-2030

Checklist

Tests added or updated (7 UT + 3 IT — all GREEN)
mvn clean verify passes locally
Spotless formatting applied (mvn spotless:apply)
No new Sonar issues (pending CI confirmation)

AI generated code

https://internal.qlik.dev/general/ways-of-working/code-reviews/#guidelines-for-ai-generated-code

this PR has been written with the help of GitHub Copilot or another generative AI tool

Introduces GET /api/v1/health (liveness probe) and GET /api/v1/readiness (readiness probe) as dedicated Kubernetes-style endpoints, replacing the insufficient /environment endpoint for cluster health monitoring. Health checks: heap memory availability (configurable threshold), component index validity, and Vault connectivity via VaultClient.ping(). Readiness check: component index load state (isStarted()). Both endpoints return {"status":"UP"|"DOWN","cause":"..."} with HTTP 200/503. Closes QTDI-2030 Co-Authored-By: GitHub Copilot <copilot@noreply.github.com>

undx · 2026-06-23T14:25:31Z

Scope & Design Review — Round 1 — APPROVED

Findings

BLOCKER B1 — Wrong path for readiness endpoint (FIXED ✅)

File: HealthResource.java, HealthResourceImpl.java, HealthResourceImplIT.java
Issue: Readiness was at /api/v1/health/readiness instead of /api/v1/readiness as confirmed by Dev.
Fix: Created ReadinessResource.java and ReadinessResourceImpl.java as separate root-level resources at @Path("readiness"). Updated IT to use /readiness path.

MAJOR M1 — Memory check divide-by-zero risk with unbounded heap (FIXED ✅)

File: HealthService.java#checkMemory()
Issue: When JVM is launched without -Xmx, Runtime.maxMemory() returns Long.MAX_VALUE. The formula availableMemory * 100L / maxMemory would overflow or produce 0%, causing a false DOWN.
Fix: Added if (maxMemory == Long.MAX_VALUE) return UP guard before the calculation.

MINOR Mi1 — `Throwable` catch for component index check (ACCEPTED — intentional)

File: HealthService.java#checkComponentIndex()
Justification: The approved plan explicitly requires catching OOME, which demands Throwable. t.getMessage() may return null for OOM but result is "Component index check failed: null" which is acceptable.

Compliance Check — Summary

Severity	Count
Critical (fixed)	1
Warning (accepted)	2

CRITICAL C1 — `catch (final Exception e)` in `VaultClient.ping()` (FIXED ✅)

Fix: Changed to catch (final javax.ws.rs.ProcessingException e) — the correct transport-level exception for JAX-RS client failures.

WARNING W1 — `catch (final Throwable t)` in `HealthService.checkComponentIndex()` (ACCEPTED)

Justification: Intentional per approved plan — OOME can only be caught with Throwable.

WARNING W2 — `MockitoAnnotations.openMocks()` instead of `@ExtendWith(MockitoExtension.class)` (ACCEPTABLE)

Justification: mockito-junit-jupiter:4.8.1 is incompatible with JUnit 5.10.0 on the test classpath. MockitoAnnotations.openMocks() achieves the same result; @InjectMocks and @Mock annotations are still used as prescribed.

AC Coverage

AC	Covered?
GET /api/v1/health → 200 when healthy	✅ UT + IT
GET /api/v1/readiness → 200 when ready	✅ UT + IT
/health → 503 + cause when memory low	✅ UT
/health → 503 + cause when Vault fails	✅ UT
/readiness → 503 + cause when index not ready	✅ UT
/environment independent from health/readiness	✅ IT
Memory threshold is configurable	✅ config property
Vault check uses VaultClient.ping()	✅ new method added
Error message with cause in JSON	✅ HealthStatus.cause field

…ess/readiness - Rename /health → /liveness (LivenessResource + LivenessResourceImpl) The /health endpoint was misleading; /liveness matches Kubernetes naming - Add FatalState singleton to record VirtualMachineError occurrences LivenessResourceImpl now returns DOWN if a fatal JVM error was recorded, instead of performing active synchronous checks that could themselves trigger OOMEs - Add DefaultExceptionHandler VirtualMachineError interception → FatalState Any OOME or other VirtualMachineError during a request marks the JVM as fatal - Add RequestContextFilter + RequestContextHolder to expose request path on the current thread, used by DefaultExceptionHandler for richer error messages - Move Vault check from liveness to ReadinessResourceImpl with 5s cache Synchronous Vault ping on the liveness path risked cascading pod restarts; moved to readiness with a TTL cache and catch(Throwable) + Response.close() - Add VaultClient.ping() timeout (configurable, default 2s) via talend.vault.cache.vault.ping.timeout - Remove HealthService (logic split into LivenessResourceImpl/ReadinessResourceImpl) - New unit tests: FatalStateTest, RequestContextHolderTest, ReadinessResourceImplTest - Rewrite HealthResourceImplIT → LivenessResourceImplIT

undx · 2026-07-07T11:43:52Z

Review round 1 — summary

Comment	Class	Action
undx — "Scope & Design Review — Round 1 — APPROVED"	Already addressed	Acknowledged — no code change needed
sonar-rnd — QG failed (0% coverage, 10 issues)	Code fix	Addressed in `95af6b895e80` — see details below

Fixes pushed: 95af6b895e80 — fix(QTDI-2030): address review round 1 — architectural refactor liveness/readiness

What changed

/health → /liveness — endpoint renamed to match Kubernetes naming conventions
FatalState singleton — records VirtualMachineError (OOME etc.) via DefaultExceptionHandler; LivenessResourceImpl is now purely reactive (no active heap/index checks that could themselves trigger OOMEs)
RequestContextFilter + RequestContextHolder — captures request path on the thread for richer fatal-error messages
ReadinessResourceImpl — Vault check moved from liveness to readiness, with 5s TTL cache + catch(Throwable) + Response.close() (avoids cascading pod restarts)
VaultClient.ping() — timeout added (default 2s, configurable via talend.vault.cache.vault.ping.timeout)
HealthService removed — logic split directly into the two resource impls
New tests: FatalStateTest (3), RequestContextHolderTest (3), ReadinessResourceImplTest (4), LivenessResourceImplIT (3 — replaces HealthResourceImplIT)

Pending clarifications: 0
Rebase: no — main was up to date

Round summary generated by AI. Please resolve threads after verifying the fixes.

Copilot

Pull request overview

This PR introduces Kubernetes probe endpoints for the component-server by adding new liveness/readiness JAX-RS resources, tracking fatal JVM errors to force restarts, and adding a Vault connectivity “ping” used by readiness logic.

Changes:

Add /api/v1/liveness and /api/v1/readiness endpoints with a shared HealthStatus response model.
Record VirtualMachineError occurrences via DefaultExceptionHandler into an application-scoped FatalState so liveness can return 503 after fatal JVM errors.
Add a VaultClient.ping() method (with configurable ping timeout) and use it from readiness with simple caching.

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
`vault-client/src/main/java/org/talend/sdk/components/vault/client/VaultClient.java`	Adds Vault connectivity `ping()` and a ping-timeout config property.
`component-server-parent/component-server/src/test/java/org/talend/sdk/component/server/service/RequestContextHolderTest.java`	Unit tests for the new request-path ThreadLocal holder.
`component-server-parent/component-server/src/test/java/org/talend/sdk/component/server/service/FatalStateTest.java`	Unit tests for fatal JVM error tracking behavior.
`component-server-parent/component-server/src/test/java/org/talend/sdk/component/server/front/ReadinessResourceImplTest.java`	Unit tests for readiness behavior (index readiness + Vault ping).
`component-server-parent/component-server/src/test/java/org/talend/sdk/component/server/front/LivenessResourceImplIT.java`	Integration tests validating probe endpoints respond successfully in the container.
`component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/service/RequestContextHolder.java`	Introduces ThreadLocal request-path storage for error context.
`component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/service/FatalState.java`	Adds application-scoped fatal error latch used by liveness endpoint.
`component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/service/ComponentManagerService.java`	Exposes `isStarted()` for readiness gating.
`component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/front/ReadinessResourceImpl.java`	Implements readiness endpoint with component-index check and cached Vault ping.
`component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/front/LivenessResourceImpl.java`	Implements liveness endpoint based on `FatalState`.
`component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/front/filter/RequestContextFilter.java`	Adds servlet filter that populates/clears `RequestContextHolder`.
`component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/front/error/DefaultExceptionHandler.java`	Records `VirtualMachineError` into `FatalState` including request-path context.
`component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/configuration/ComponentServerConfiguration.java`	Adds (currently unused) heap-threshold config property for health checks.
`component-server-parent/component-server/pom.xml`	Adds `mockito-core` test dependency for new unit tests.
`component-server-parent/component-server-model/src/main/java/org/talend/sdk/component/server/front/model/HealthStatus.java`	Adds `HealthStatus` DTO used by probe responses.
`component-server-parent/component-server-api/src/main/java/org/talend/sdk/component/server/api/ReadinessResource.java`	Defines readiness API contract and OpenAPI metadata.
`component-server-parent/component-server-api/src/main/java/org/talend/sdk/component/server/api/LivenessResource.java`	Defines liveness API contract and OpenAPI metadata.

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@context

…ural refinements - LivenessResource: rename JVM → Application in API response descriptions (U1, U2) - ComponentServerConfiguration: remove unused healthMemoryThreshold field (U3) - ComponentServerConfiguration: add healthVaultEnabled flag (default false) (U4) - ReadinessResourceImpl: gate Vault check behind healthVaultEnabled flag (U4) - ReadinessResourceImpl: fix race — update lastVaultCheck after result (C1) - ReadinessResourceImpl: re-throw VirtualMachineError before catch(Throwable) (C1) - ComponentManagerService: make started field volatile (C5) - DefaultExceptionHandler: replace RequestContextHolder with @context HttpServletRequest (C6) - VaultClient: use dedicated ClientBuilder for ping with connect/read timeout (C7) - FatalState: add reset() method for test isolation (U5) - LivenessResourceImplIT: add test for FatalState.markFatal() → /liveness 503 (U5)

undx · 2026-07-07T13:13:27Z

Review round 2 — summary

Comment	Class	Action
U1 — undx: `JVM` → `Application` (L44)	Code fix	Fixed in `77896cbef1a2`
U2 — undx: same rename (L48)	Code fix	Fixed in `77896cbef1a2`
U3 — undx: remove unused `healthMemoryThreshold`	Code fix	Fixed in `77896cbef1a2`
U4 — undx: gate Vault check behind a flag	Code fix (design)	Fixed in `77896cbef1a2` — `healthVaultEnabled` added, default `false`
U5 — undx: add FatalState IT test	Code fix (test)	Fixed in `77896cbef1a2` — `livenessReturns503WhenFatalErrorRecorded`
C1 — Copilot: lastVaultCheck race + VME re-throw	Code fix	Fixed in `77896cbef1a2`
C2 — Copilot: gating only on component index	Already addressed	By U4
C3 — Copilot: PR description /health → /liveness	Cannot edit	PR description cannot be edited after creation per workflow rules
C4 — Copilot: healthMemoryThreshold unused	Already addressed	By U3
C5 — Copilot: `started` not volatile	Code fix	Fixed in `77896cbef1a2`
C6 — Copilot: RequestContextHolder ThreadLocal	Code fix	Fixed in `77896cbef1a2` — @context HttpServletRequest
C7 — Copilot: stringly-typed ping timeout	Code fix	Fixed in `77896cbef1a2` — dedicated ClientBuilder

Fixes pushed: 77896cbef1a2 — fix(QTDI-2030): address review round 2 — liveness/readiness architectural refinements
Pending clarifications: 0
Rebase: no — base branch had not moved

Round summary generated by AI. Please resolve threads after verifying the fixes.

…plTest

Copilot

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 3 comments.

…ntextFilter

Copilot

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 7 comments.

…eption handler hardening, TTL race, resource leaks - VaultClient.ping(): return true only on HTTP 200 (initialized, unsealed, active) instead of unconditionally for any response. - DefaultExceptionHandler: drop exception.getMessage() from the VirtualMachineError cause string to avoid allocation during an already-failing JVM. - ReadinessResourceImpl.checkVaultCached(): synchronize the TTL refresh path (double-checked) so only one thread pings Vault per TTL window. - LivenessResourceImplIT: wrap all Response usages in try-with-resources. - Add unit test coverage for the above (VaultClientTest, new DefaultExceptionHandlerTest, ReadinessResourceImplTest concurrency test) to satisfy the Sonar quality gate. Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

undx · 2026-09-01T09:02:44Z

Review round 3 — summary

Comment	Class	Action
C8 — `VaultClient.java:234` — `ping()` returns `true` regardless of status	Code fix	Fixed in `f03d4a58924d`
C9 — `DefaultExceptionHandler.java:66` — allocation risk building cause string	Code fix	Fixed in `f03d4a58924d`
C10 — `LivenessResourceImplIT.java:50` — Response not closed	Code fix (test)	Fixed in `f03d4a58924d`
C11 — `LivenessResourceImplIT.java:60` — Response not closed	Code fix (test)	Fixed in `f03d4a58924d`
C12 — `LivenessResourceImplIT.java:75` — 3x Response not closed	Code fix (test)	Fixed in `f03d4a58924d`
C13 — `LivenessResourceImplIT.java` — Response not closed	Code fix (test)	Fixed in `f03d4a58924d`
C14 — `ReadinessResourceImpl.java:110` — unsynchronized TTL check allows concurrent Vault pings	Code fix	Fixed in `f03d4a58924d`
S1 — Sonar QG — 0.00% coverage on new code	Code fix	New/updated UT coverage added in `f03d4a58924d` (`VaultClientTest`, new `DefaultExceptionHandlerTest`, `ReadinessResourceImplTest` concurrency test)

Fixes pushed: f03d4a58924d — fix(QTDI-2030): address review round 3 — vault ping status check, exception handler hardening, TTL race, resource leaks
Pending clarifications: none
Rebase: not needed — origin/master had not moved ahead of the branch

Round summary generated by AI. Please resolve threads after verifying the fixes.

Signed: Claude Sonnet 4.5

Copilot

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 3 comments.

…ig key prefix, vault error leak Guard against request.getRequestURI() returning null in DefaultExceptionHandler, rename the health.vault.enabled config key to the talend.component.server.* prefix used elsewhere in ComponentServerConfiguration, and stop leaking low-level transport/SSL details via t.getMessage() in the readiness response cause. Extend unit test coverage for the new branches. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

undx · 2026-09-01T09:41:57Z

Review round 4 — summary

Comment	Class	Action
#1 — `request.getRequestURI()` can return null (`DefaultExceptionHandler.java:63`)	Code fix	Fixed in `2a27dfc274bd`
#2 — config key uses `talend.server.` instead of `talend.component.server.` prefix (`ComponentServerConfiguration.java:210`)	Code fix	Fixed in `2a27dfc274bd`
#3 — readiness cause leaks `t.getMessage()` transport/SSL details (`ReadinessResourceImpl.java:107`)	Code fix	Fixed in `2a27dfc274bd`
#4 — Sonar Quality Gate: 50.50% coverage on new code (< 80% required)	Code fix	Added/extended unit test assertions covering the null-URI and generic-cause branches in `2a27dfc274bd`

Fixes pushed: 2a27dfc274bd — fix(QTDI-2030): address review round 4 — null request URI guard, config key prefix, vault error leak
Pending clarifications: 0
Rebase: no — origin/master had not moved since the last push

Round summary generated by AI. Please resolve threads after verifying the fixes.

Copilot

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated no new comments.

Suppressed comments (1)

Previously missed (1) — in code that hasn't changed since the last review.

component-server-parent/component-server/src/test/java/org/talend/sdk/component/server/front/ReadinessResourceImplTest.java:85

returns200WhenIndexReadyAndVaultReachable() disables the Vault check (healthVaultEnabled=false), so the test name is misleading (it doesn’t assert anything about Vault reachability). Renaming it will make intent and coverage clearer.

    void returns200WhenIndexReadyAndVaultReachable() {
        when(componentManagerService.isStarted()).thenReturn(true);
        when(configuration.getHealthVaultEnabled()).thenReturn(false);

Extract the duplicated "Vault is not reachable" string into a VAULT_NOT_REACHABLE constant in ReadinessResourceImpl, replacing all 3 call sites. No behavioural change. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

undx · 2026-09-01T10:34:23Z

Review round 5 — summary

Comment	Class	Action
Sonar — "Define a constant instead of duplicating this literal "Vault is not reachable" 3 times." (`ReadinessResourceImpl.java:80`)	Code fix	Fixed in `294c7a7ccb9e`

Fixes pushed: 294c7a7ccb9e — fix(QTDI-2030): address review round 5 — Sonar duplicated literal
Pending clarifications: none
Rebase: no — master had not moved ahead

Round summary generated by AI. Please resolve threads after verifying the fixes.

sonar-rnd · 2026-09-01T11:52:18Z

Quality Gate passed

Issues

Measures

Project ID: org.talend.sdk.component:component-runtime

View in SonarQube

undx commented Jul 7, 2026

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Merge branch 'master' into copilot/QTDI-2030_health_readiness_endpoints

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fix(QTDI-3020): fix sonar issues

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undx and others added 2 commits September 1, 2026 10:22

Merge branch 'master' into copilot/QTDI-2030_health_readiness_endpoints

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Summary

Checklist

AI generated code

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undx commented Jun 23, 2026

Scope & Design Review — Round 1 — APPROVED

Findings

BLOCKER B1 — Wrong path for readiness endpoint (FIXED ✅)

MAJOR M1 — Memory check divide-by-zero risk with unbounded heap (FIXED ✅)

MINOR Mi1 — Throwable catch for component index check (ACCEPTED — intentional)

Compliance Check — Summary

CRITICAL C1 — catch (final Exception e) in VaultClient.ping() (FIXED ✅)

WARNING W1 — catch (final Throwable t) in HealthService.checkComponentIndex() (ACCEPTED)

WARNING W2 — MockitoAnnotations.openMocks() instead of @ExtendWith(MockitoExtension.class) (ACCEPTABLE)

AC Coverage

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undx commented Jul 7, 2026

Review round 1 — summary

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undx commented Jun 23, 2026 •

edited by atlassian Bot

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MINOR Mi1 — `Throwable` catch for component index check (ACCEPTED — intentional)

CRITICAL C1 — `catch (final Exception e)` in `VaultClient.ping()` (FIXED ✅)

WARNING W1 — `catch (final Throwable t)` in `HealthService.checkComponentIndex()` (ACCEPTED)

WARNING W2 — `MockitoAnnotations.openMocks()` instead of `@ExtendWith(MockitoExtension.class)` (ACCEPTABLE)