Fixed - ClusterConnectionManager.checkSlotsMigration() method throws NPE #6048

redisson/src/main/java/org/redisson/cluster/ClusterConnectionManager.java

@@ -754,12 +754,18 @@ public class ClusterConnectionManager extends MasterSlaveConnectionManager {
         Collection<ClusterPartition> clusterLastPartitions = getLastPartitions();
 
         // https://github.com/redisson/redisson/issues/3635
-        Map<String, MasterSlaveEntry> nodeEntries = clusterLastPartitions.stream().collect(Collectors.toMap(p -> p.getNodeId(),
+        Map<String, MasterSlaveEntry> nodeEntries = clusterLastPartitions.stream()
+                                                                          .filter(e -> getEntry(e.getSlotRanges().iterator().next().getStartSlot()) != null)
+                                                                          .collect(Collectors.toMap(p -> p.getNodeId(),
                                                                                     p -> getEntry(p.getSlotRanges().iterator().next().getStartSlot())));
 
         Set<Integer> changedSlots = new HashSet<>();
         for (ClusterPartition currentPartition : clusterLastPartitions) {
             String nodeId = currentPartition.getNodeId();
+            if (!nodeEntries.containsKey(nodeId)) {
+                continue;
+            }
+
             for (ClusterPartition newPartition : newPartitions) {
                 if (!Objects.equals(nodeId, newPartition.getNodeId())
                         || newPartition.getSlotRanges().equals(currentPartition.getSlotRanges())) {