GH-10546: Fix RedisLockRegistry for cluster

Fixes: #10546

* pass `unLockChannelKey` as `ARGV[2]` instead of `KEYS[2]` to make this unlock script compatible with both Redis cluster and AWS Elastic valkey cluster
* add documentation for AWS ElastiCache Valkey Support in `RedisLockRegistry`

Signed-off-by: Severin Kistler <[email protected]>

**Auto-cherry-pick to `6.4.x`**
# Conflicts:
#	spring-integration-redis/src/main/java/org/springframework/integration/redis/util/RedisLockRegistry.java
#	src/reference/antora/modules/ROOT/pages/redis.adoc

Author: kistlers

spring-integration-redis/src/main/java/org/springframework/integration/redis/util/RedisLockRegistry.java

@@ -668,7 +668,7 @@ private final class RedisPubSubLock extends RedisLock {
 		private static final String UNLINK_UNLOCK_SCRIPT = """
 				local lockClientId = redis.call('GET', KEYS[1])
 				if (lockClientId == ARGV[1] and redis.call('UNLINK', KEYS[1]) == 1) then
-					redis.call('PUBLISH', KEYS[2], KEYS[1])
+					redis.call('PUBLISH', ARGV[2], KEYS[1])
 					return true
 				end
 				return false
@@ -711,8 +711,8 @@ protected boolean removeLockKeyInnerDelete() {
 		private boolean removeLockKeyWithScript(RedisScript<Boolean> redisScript) {
 			String unLockChannelKeyToUse = RedisLockRegistry.this.unLockChannelKey + ":" + this.lockKey;
 			return Boolean.TRUE.equals(RedisLockRegistry.this.redisTemplate.execute(
-					redisScript, List.of(this.lockKey, unLockChannelKeyToUse),
-					RedisLockRegistry.this.clientId));
+					redisScript, List.of(this.lockKey),
+					RedisLockRegistry.this.clientId, unLockChannelKey));
 		}
 
 		private boolean subscribeLock(long time) throws ExecutionException, InterruptedException {

src/reference/antora/modules/ROOT/pages/redis.adoc

@@ -862,3 +862,26 @@ Starting with version 6.4, instead of throwing `IllegalStateException`, the `Red
 
 Starting with version 6.4, a `RedisLockRegistry.setRenewalTaskScheduler()` is added to configure the scheduler for periodic renewal of locks.
 When it is set, the lock will be automatically renewed every `1/3` of the expiration time after the lock is successfully acquired, until unlocked or the redis key is removed.
+
+[[elasticache-valkey-cluster]]
+=== AWS ElastiCache for Valkey Support in cluster mode
+
+Starting with version 6.4.9/6.5.4/7.0.0, `RedisLockRegistry` supports AWS Elasticache for Valkey in cluster mode.
+In this version of valkey (a redis drop-in replacement), all PubSub operations (`PUBLISH`, `SUBSCRIBE`, etc.) use their sharded variants (`SPUBLISH`, `SSUBSCRIBE`, etc.) internally.
+If you are observing errors in the form of:
+
+[source]
+----
+Caused by: io.lettuce.core.RedisCommandExecutionException: ERR Script attempted to access keys that do not hash to the same slot script: b2dedc0ab01c17f9f20e3e6ddb62dcb6afbed0bd, on @user_script:3.
+----
+
+in the `unlock` step of the `RedisLockRegistry`,  you have to supply a lock key that includes a hash tag `{...}` to ensure all operations in the `unlock` script are hashed to the same cluster slot/shard, e.g.:
+
+[source]
+----
+RedisLockRegistry lockRegistry = new RedisLockRegistry("my-lock-key{choose_your_tag}");
+
+lockRegistry.lock();
+# critical section
+lockRegistry.unlock();
+----