Reset round robin on cluster node RedisURI change

src/main/java/io/lettuce/core/cluster/RoundRobin.java

@@ -18,6 +18,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.function.BiFunction;
 
 /**
  * Circular element provider. This class allows infinite scrolling over a collection with the possibility to provide an initial
@@ -31,6 +32,16 @@ class RoundRobin<V> {
 
     protected volatile V offset;
 
+    private final BiFunction<V, V, Boolean> hasElementChanged;
+
+    public RoundRobin() {
+        this((a, b) -> false);
+    }
+
+    public RoundRobin(BiFunction<V, V, Boolean> hasElementChanged) {
+        this.hasElementChanged = hasElementChanged;
+    }
+
     /**
      * Return whether this {@link RoundRobin} is still consistent and contains all items from the leader {@link Collection} and
      * vice versa.
@@ -42,7 +53,19 @@ public boolean isConsistent(Collection<? extends V> leader) {
 
         Collection<? extends V> collection = this.collection;
 
-        return collection.containsAll(leader) && leader.containsAll(collection);
+        for (V currentElement : collection) {
+            boolean found = false;
+            for (V searchedElement : leader) {
+                if (searchedElement.equals(currentElement) && !hasElementChanged.apply(currentElement, searchedElement)) {
+                    found = true;
+                }
+            }
+            if (!found) {
+                return false;
+            }
+        }
+
+        return collection.size() == leader.size();
     }
 
     /**

src/main/java/io/lettuce/core/cluster/RoundRobinSocketAddressSupplier.java

@@ -52,7 +52,7 @@ public RoundRobinSocketAddressSupplier(Supplier<Partitions> partitions,
         LettuceAssert.notNull(sortFunction, "Sort-Function must not be null");
 
         this.partitions = partitions;
-        this.roundRobin = new RoundRobin<>();
+        this.roundRobin = new RoundRobin<>((a, b) -> !a.getUri().equals(b.getUri()));
         this.sortFunction = (Function) sortFunction;
         this.clientResources = clientResources;
         resetRoundRobin(partitions.get());

src/test/java/io/lettuce/core/cluster/RoundRobinSocketAddressSupplierUnitTests.java

@@ -46,11 +46,13 @@ class RoundRobinSocketAddressSupplierUnitTests {
     private static RedisURI hap2 = new RedisURI("127.0.0.1", 2, Duration.ofSeconds(1));
     private static RedisURI hap3 = new RedisURI("127.0.0.1", 3, Duration.ofSeconds(1));
     private static RedisURI hap4 = new RedisURI("127.0.0.1", 4, Duration.ofSeconds(1));
+    private static RedisURI hap5 = new RedisURI("127.0.0.0", 5, Duration.ofSeconds(1));
 
     private static InetSocketAddress addr1 = new InetSocketAddress(hap1.getHost(), hap1.getPort());
     private static InetSocketAddress addr2 = new InetSocketAddress(hap2.getHost(), hap2.getPort());
     private static InetSocketAddress addr3 = new InetSocketAddress(hap3.getHost(), hap3.getPort());
     private static InetSocketAddress addr4 = new InetSocketAddress(hap4.getHost(), hap4.getPort());
+    private static InetSocketAddress addr5 = new InetSocketAddress(hap5.getHost(), hap5.getPort());
 
     private static Partitions partitions;
 
@@ -85,6 +87,24 @@ void noOffset() {
         assertThat(sut.get()).isNotEqualTo(addr3);
     }
 
+    @Test
+    void nodeIPChanges() {
+
+        RoundRobinSocketAddressSupplier sut = new RoundRobinSocketAddressSupplier(() -> partitions,
+                redisClusterNodes -> redisClusterNodes, clientResourcesMock);
+
+        assertThat(sut.get()).isEqualTo(addr1);
+
+        assertThat(partitions.remove(new RedisClusterNode(hap1, "2", true, "", 0, 0, 0, new ArrayList<>(), new HashSet<>())))
+                .isTrue();
+        assertThat(partitions.add(new RedisClusterNode(hap5, "2", true, "", 0, 0, 0, new ArrayList<>(), new HashSet<>())))
+                .isTrue();
+
+        assertThat(sut.get()).isEqualTo(addr1);
+        assertThat(sut.get()).isEqualTo(addr3);
+        assertThat(sut.get()).isEqualTo(addr5);
+    }
+
     @Test
     void partitionTableChangesNewNode() {