fix: handle discovery upstream DELETE events in path data sync (#6661)

[wy471x]

Make sure that:

• You have read the contribution guidelines.
• You submit test cases (unit or integration tests) that back your changes.
• Your local test passed ./mvnw clean install -Dmaven.javadoc.skip=true.

Summary

Fixes #6661.

Path-based sync services (etcd / zookeeper / consul, all extending AbstractPathDataSyncService) do receive delete notifications for discovery upstream nodes: EtcdSyncDataService.watchChildChange fires super.event(configNamespace, deletePath, null, registerPath, EventType.DELETE) (EtcdSyncDataService.java:88), and event() dispatches it to discoveryUpstreamHandlerEvent. But that handler only acted when the event was not a delete, so the DELETE was silently dropped and DiscoveryUpstreamDataSubscriber#unSubscribe was never called. Every other entity in the same class (plugin, selector, rule, app auth, meta data, proxy selector) already handles DELETE.

Changes:

1. AbstractPathDataSyncService.discoveryUpstreamHandlerEvent (AbstractPathDataSyncService.java:132) — added the missing DELETE branch: parses pluginName and the last path segment with the same split("/") pattern used by proxyHandlerEvent, builds a DiscoverySyncData carrying them, and calls the new un-cache hook. The PUT path is unchanged.
2. AbstractPathDataSyncService.unCacheDiscoveryUpstreamData (AbstractPathDataSyncService.java:290) — new protected hook delegating to discoveryUpstreamDataSubscribers.forEach(e -> e.unSubscribe(...)), mirroring the existing unCacheProxySelectorData / unCacheMetaData helpers and the node-based counterpart AbstractNodeDataSyncService.unCacheDiscoveryUpstreamData.

Note on the parsed path segment: the discovery-upstream path ends with the selector id, not the selector name — AbstractPathDataChangedListener.onDiscoveryUpstreamChanged builds it with buildDiscoveryUpstreamPath(data.getNamespaceId(), data.getPluginName(), data.getSelectorId()), and the node-based sync sets selectorId for the same reason. This PR therefore sets selectorId (the issue text suggested "selector name").

Test Cases:

• AbstractPathDataSyncServiceTest#testDiscoveryUpstreamHandlerEvent (AbstractPathDataSyncServiceTest.java:93) — dispatches event(...) for /{ns}/shenyu/discoveryUpstream/divide/{selectorId}: PUT triggers onSubscribe, DELETE triggers unSubscribe, and the captured DiscoverySyncData carries pluginName=divide / selectorId=testSelectorId.

Verification

• ./mvnw clean install -Dmaven.javadoc.skip=true on JDK 21: whole reactor passes, with the one pre-existing order-dependent test excluded (-Dtest='!DubboReconcilerTest' -DfailIfNoTests=false). org.apache.shenyu.k8s.DubboReconcilerTest shares the static IngressCache with WebSocketReconcilerTest / DivideIngressReconcilerTest (all use mockedNamespace/mockedIngress) and fails purely on test execution order: it passes in isolation and reproduces the same failure on unmodified master. shenyu-kubernetes-controller does not depend on shenyu-sync-data-api.
• Touched module and its dependents: shenyu-sync-data-api, shenyu-sync-data-etcd, shenyu-sync-data-zookeeper, shenyu-sync-data-consul — all tests pass.
• checkstyle:check — 0 violations.

Not covered here: the gateway-side CommonDiscoveryUpstreamDataSubscriber#unSubscribe is still a no-op (//ignore), so actually evicting the cached upstream list (UpstreamCacheManager.removeByKey(selectorId)) on deletion remains a separate change in the discovery plugin handlers.

@Aias00, could you please help review this PR? Thank you!

close #6661

[Copilot]

🟡 Changes recommended

The Zookeeper adapter still drops DELETE events when data is null, so they do not reach the new handler.

Get a fresh assessment by requesting another Copilot review.

Pull request overview

Fixes path-based discovery-upstream DELETE handling and adds regression coverage.

Changes:

• Dispatches DELETE events to subscribers and parses selector IDs.
• Adds PUT/DELETE handler tests.

File summaries

File	Reviewed changes
shenyu-sync-data-center/shenyu-sync-data-api/src/test/java/org/apache/shenyu/sync/data/core/AbstractPathDataSyncServiceTest.java	Tests discovery-upstream PUT and DELETE notifications.
shenyu-sync-data-center/shenyu-sync-data-api/src/main/java/org/apache/shenyu/sync/data/core/AbstractPathDataSyncService.java	Adds DELETE handling and subscriber uncache delegation.

Review details

Suppressed comments (1)

shenyu-sync-data-center/shenyu-sync-data-api/src/main/java/org/apache/shenyu/sync/data/core/AbstractPathDataSyncService.java:143

• This new branch only forwards the delete to DiscoveryUpstreamDataSubscriber, but the production CommonDiscoveryUpstreamDataSubscriber.unSubscribe implementation is still a no-op, so the normal gateway path performs no cache eviction and stale upstreams continue receiving traffic. Please include the downstream eviction (by selectorId) in this fix, or scope the PR/issue claim so it does not present #6661 as resolved.

            unCacheDiscoveryUpstreamData(discoverySyncData);

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Lite

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Aias00]

Approved as PMC (Aias00). Small, well-scoped fix with regression tests; green CI, mergeable. Reviewed the diff.