Fixed a data loss issue on lite member promotion

hazelcast/src/main/java/com/hazelcast/internal/cluster/impl/MembershipManager.java

@@ -305,11 +305,15 @@ void updateMembers(MembersView membersView) {
 
         MemberImpl[] members = new MemberImpl[membersView.size()];
         int memberIndex = 0;
+        boolean updatedLiteMember = false;
         for (MemberInfo memberInfo : membersView.getMembers()) {
             Address address = memberInfo.getAddress();
             MemberImpl member = currentMemberMap.getMember(address);
 
             if (member != null && member.getUuid().equals(memberInfo.getUuid())) {
+                if (member.isLiteMember()) {
+                    updatedLiteMember = true;
+                }
                 member = createNewMemberImplIfChanged(memberInfo, member);
                 members[memberIndex++] = member;
                 continue;
@@ -342,6 +346,10 @@ void updateMembers(MembersView membersView) {
 
         setMembers(MemberMap.createNew(membersView.getVersion(), members));
 
+        if (updatedLiteMember) {
+            updateMembersGroupSize();
+        }
+
         for (MemberImpl member : removedMembers) {
             closeConnection(member.getAddress(), "Member left event received from master");
             handleMemberRemove(memberMapRef.get(), member);
@@ -410,6 +418,10 @@ private MemberImpl createMember(MemberInfo memberInfo, Map<String, String> attri
                       .build();
     }
 
+    private void updateMembersGroupSize() {
+        node.partitionService.updateMemberGroupSize();
+    }
+
     private void repairPartitionTableIfReturningMember(MemberImpl member) {
         if (!clusterService.isMaster()) {
             return;

hazelcast/src/main/java/com/hazelcast/internal/partition/impl/InternalPartitionServiceImpl.java

@@ -346,6 +346,10 @@ public int getMaxAllowedBackupCount() {
         return max(min(getMemberGroupsSize() - 1, InternalPartition.MAX_BACKUP_COUNT), 0);
     }
 
+    public void updateMemberGroupSize() {
+        partitionStateManager.updateMemberGroupsSize();
+    }
+
     @Override
     public void memberAdded(Member member) {
         logger.fine("Adding " + member);

hazelcast/src/test/java/com/hazelcast/internal/cluster/impl/PromoteLiteMemberTest.java

@@ -27,6 +27,7 @@
 import com.hazelcast.internal.partition.InternalPartition;
 import com.hazelcast.internal.util.RootCauseMatcher;
 import com.hazelcast.internal.util.UuidUtil;
+import com.hazelcast.map.IMap;
 import com.hazelcast.spi.impl.InternalCompletableFuture;
 import com.hazelcast.spi.impl.operationservice.impl.Invocation;
 import com.hazelcast.spi.impl.operationservice.impl.InvocationRegistry;
@@ -64,9 +65,11 @@
 import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
 import static org.hamcrest.Matchers.greaterThan;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 @RunWith(HazelcastParallelClassRunner.class)
@@ -323,6 +326,86 @@ public void promotion_shouldFail_whenMasterIsSuspected_duringPromotion() throws
         }
     }
 
+    @Test
+    public void lite_member_promotion_data_loss() throws InterruptedException {
+        int entryCount = 1000;
+
+        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory();
+        Config config = new Config().setLiteMember(true);
+
+        // start first hazelcast instance as a lite member
+        HazelcastInstance firstHazelcastInstance = factory.newHazelcastInstance(config);
+
+        // start second and third hazelcast instances as a lite member
+        HazelcastInstance secondHazelcastInstance = factory.newHazelcastInstance(config);
+        HazelcastInstance thirdHazelcastInstance = factory.newHazelcastInstance(config);
+
+        // promote all instances to data members
+        firstHazelcastInstance.getCluster().promoteLocalLiteMember();
+        secondHazelcastInstance.getCluster().promoteLocalLiteMember();
+        thirdHazelcastInstance.getCluster().promoteLocalLiteMember();
+
+        // check if cluster is in a good shape
+        assertTrueEventually(() -> assertTrue(firstHazelcastInstance.getPartitionService().isClusterSafe()));
+
+        // insert some dummy data into the testing map
+        String mapName = randomMapName();
+        IMap<String, String> testMap = firstHazelcastInstance.getMap(mapName);
+        for (int i = 0; i < entryCount; ++i) {
+            testMap.put("key" + i, "value" + i);
+        }
+
+        // check all data is correctly inserted
+        assertEquals(entryCount, testMap.size());
+
+        // kill second instance
+        secondHazelcastInstance.getLifecycleService().terminate();
+
+        // backup count for the map is set to 1
+        // even with 1 node down, no data loss is expected
+        assertTrueEventually(() -> assertEquals(entryCount, firstHazelcastInstance.getMap(mapName).size()));
+        assertTrueEventually(() -> assertEquals(entryCount, thirdHazelcastInstance.getMap(mapName).size()));
+    }
+
+    @Test
+    public void lite_member_promotion_data_loss2() throws InterruptedException {
+        int entryCount = 1000;
+
+        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory();
+        Config config = new Config().setLiteMember(true);
+
+        // start first hazelcast instance as a lite member
+        HazelcastInstance firstHazelcastInstance = factory.newHazelcastInstance(config);
+
+        // start second hazelcast instance as a lite member
+        HazelcastInstance secondHazelcastInstance = factory.newHazelcastInstance(config);
+
+        // promote all instances to data members
+        firstHazelcastInstance.getCluster().promoteLocalLiteMember();
+
+        secondHazelcastInstance.getCluster().promoteLocalLiteMember();
+
+        // check if cluster is in a good shape
+        assertTrueEventually(() -> assertTrue(firstHazelcastInstance.getPartitionService().isClusterSafe()));
+
+        // insert some dummy data into the testing map
+        String mapName = randomMapName();
+        IMap<String, String> testMap = firstHazelcastInstance.getMap(mapName);
+        for (int i = 0; i < entryCount; ++i) {
+            testMap.put("key" + i, "value" + i);
+        }
+
+        // check all data is correctly inserted
+        assertEquals(entryCount, testMap.size());
+
+        // kill second instance
+        secondHazelcastInstance.getLifecycleService().terminate();
+
+        // backup count for the map is set to 1
+        // even with 1 node down, no data loss is expected
+        assertTrueEventually(() -> assertEquals(entryCount, firstHazelcastInstance.getMap(mapName).size()));
+    }
+
     private void assertPromotionInvocationStarted(HazelcastInstance instance) {
         OperationServiceImpl operationService = getNode(instance).getNodeEngine().getOperationService();
         InvocationRegistry invocationRegistry = operationService.getInvocationRegistry();