From a61327766ee89250a39f6923e7687aa5766f342d Mon Sep 17 00:00:00 2001
From: Artem Bilan <abilan@pivotal.io>
Date: Tue, 7 Nov 2017 15:59:54 -0500
Subject: [PATCH] GH-2207: Clarify RedisMetadataStore in cluster

Resolves: spring-projects/spring-integration#2207

* Since the `WATCH` command isn't supported on clustered connections,
the `RedisMetadataStore.replace()` operation can't be used there.
Document this limitation
---
 .../redis/metadata/RedisMetadataStore.java            | 11 ++++++++---
 src/reference/asciidoc/redis.adoc                     |  2 ++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/spring-integration-redis/src/main/java/org/springframework/integration/redis/metadata/RedisMetadataStore.java b/spring-integration-redis/src/main/java/org/springframework/integration/redis/metadata/RedisMetadataStore.java
index 0f8efd9908..1f8d3f9b9f 100644
--- a/spring-integration-redis/src/main/java/org/springframework/integration/redis/metadata/RedisMetadataStore.java
+++ b/spring-integration-redis/src/main/java/org/springframework/integration/redis/metadata/RedisMetadataStore.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2016 the original author or authors.
+ * Copyright 2013-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,11 +26,16 @@ import org.springframework.integration.metadata.MetadataStore;
 import org.springframework.util.Assert;
 
 /**
- * Redis implementation of {@link MetadataStore}. Use this {@link MetadataStore}
- * to achieve meta-data persistence across application restarts.
+ * Redis implementation of {@link MetadataStore}. Use this {@link MetadataStore} to
+ * achieve meta-data persistence across application restarts.
+ * <p>
+ * This implementation is based on the {@link RedisProperties} and its
+ * {@link #replace(String, String, String)}; it can't currently be used with a Redis
+ * cluster because the {@code WATCH} command is not supported.
  *
  * @author Gunnar Hillert
  * @author Artem Bilan
+ *
  * @since 3.0
  */
 public class RedisMetadataStore implements ConcurrentMetadataStore {
diff --git a/src/reference/asciidoc/redis.adoc b/src/reference/asciidoc/redis.adoc
index 5a3c477383..fe48fd7860 100644
--- a/src/reference/asciidoc/redis.adoc
+++ b/src/reference/asciidoc/redis.adoc
@@ -418,6 +418,8 @@ By default this `key` has the value `MetaData`.
 
 Starting with _version 4.0_, this store now implements `ConcurrentMetadataStore`, allowing it to be reliably shared across multiple application instances where only one instance will be allowed to store or modify a key's value.
 
+IMPORTANT: The `RedisMetadataStore.replace()` (for example in the `AbstractPersistentAcceptOnceFileListFilter`) can't be used with a Redis cluster since the `WATCH` command for atomicity is not currently supported.
+
 [[redis-store-inbound-channel-adapter]]
 === RedisStore Inbound Channel Adapter