Add Valkey cluster backplane and sticky-410 ownership (clusters) (Stirling-Tools#6472)

Author: Frooodle

app/common/src/main/java/stirling/software/common/cluster/RateLimitStore.java

@@ -2,7 +2,13 @@
 
 import java.time.Duration;
 
-/** Token-bucket rate limiting backed by the cluster backplane. */
+/**
+ * Token-bucket rate limiting backed by the cluster backplane.
+ *
+ * <p>In-process implementations enforce a per-JVM limit; distributed implementations enforce a
+ * single global limit across every node. Both use a Bucket4j greedy-refill token bucket so the
+ * semantics match across single-node and cluster deployments.
+ */
 public interface RateLimitStore {
 
     /**

app/common/src/main/java/stirling/software/common/service/JobExecutorService.java

@@ -24,7 +24,9 @@ void acquireReleaseAcquire() {
     }
 
     @Test
-    void reentryFromSameThreadFails() {
+    void reentryFromSameThreadFails_parityWithValkey() {
+        // The Valkey impl refuses reentry (SET NX semantics); the in-process impl must match,
+        // otherwise code working in single-instance silently breaks in cluster mode.
         DistributedLock lock = new InProcessDistributedLock();
         DistributedLock.LockHandle h1 = lock.tryAcquire("k", Duration.ofSeconds(30)).orElseThrow();
         Optional<DistributedLock.LockHandle> reentry = lock.tryAcquire("k", Duration.ofSeconds(30));

app/common/src/test/java/stirling/software/common/cluster/inprocess/InProcessDistributedLockTest.java

@@ -86,6 +86,8 @@ public String localNodeId() {
 
                     @Override
                     public boolean shouldRunLocalCleanup() {
+                        // Distributed backplanes own job TTL eviction themselves; this mock
+                        // mirrors the real ValkeyClusterBackplane override of the default true.
                         return false;
                     }
                 };