diff --git a/modules/core/src/main/java/org/apache/ignite/internal/CoreMessagesProvider.java b/modules/core/src/main/java/org/apache/ignite/internal/CoreMessagesProvider.java
index 460cb7bcc1043..153afb99e94f9 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/CoreMessagesProvider.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/CoreMessagesProvider.java
@@ -338,8 +338,8 @@ public CoreMessagesProvider(Marshaller dfltMarsh, Marshaller schemaAwareMarsh, C
 
         this.factory = factory;
 
-        // [-44, 0..2, 42, 200..204, 210, 302] - Use in tests.
-        // [300..307, 350..352] - CalciteMessageFactory.
+        // [-44, 0..2, 42, 200..204, 210] - Use in tests.
+        // [300 - 500] - CalciteMessageFactory.
         // [-4..-22, -30..-35, -54..-57] - SQL
 
         // [5000 - 5500]: Utility messages. Most of them originally come from Discovery.
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/distributed/dht/PartitionUpdateCountersMessage.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/distributed/dht/PartitionUpdateCountersMessage.java
index 55a90f49a3374..d24ab7d7982be 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/distributed/dht/PartitionUpdateCountersMessage.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/distributed/dht/PartitionUpdateCountersMessage.java
@@ -19,35 +19,37 @@
 
 import java.util.Arrays;
 import java.util.Map;
-import org.apache.ignite.IgniteCheckedException;
-import org.apache.ignite.internal.MarshallableMessage;
 import org.apache.ignite.internal.Order;
 import org.apache.ignite.internal.util.GridUnsafe;
 import org.apache.ignite.internal.util.typedef.internal.U;
-import org.apache.ignite.marshaller.Marshaller;
+import org.apache.ignite.plugin.extensions.communication.Message;
+import org.apache.ignite.plugin.extensions.communication.MessageFactory;
 
 /**
  * Partition update counters message.
+ *
+ * @see #finishUpdating()
  */
-public class PartitionUpdateCountersMessage implements MarshallableMessage {
+public class PartitionUpdateCountersMessage implements Message {
     /** */
     private static final int ITEM_SIZE = 4 /* partition */ + 8 /* initial counter */ + 8 /* updates count */;
 
-    /** Byte representation of partition counters. */
+    /** */
     @Order(0)
-    byte[] data;
+    int cacheId;
 
-    /** */
+    /** Byte representation of partition counters. */
     @Order(1)
-    int cacheId;
+    byte[] data;
 
     /** */
-    private int size;
+    @Order(2)
+    int size;
 
     /** Used for assigning counters to cache entries during tx finish. */
     private Map<Integer, Long> counters;
 
-    /** */
+    /** Empty constructor for a {@link MessageFactory}. */
     public PartitionUpdateCountersMessage() {
         // No-op.
     }
@@ -120,6 +122,8 @@ public long updatesCount(int idx) {
      * @param part Partition number.
      * @param init Init partition counter.
      * @param updatesCnt Update counter delta.
+     *
+     * @see #finishUpdating()
      */
     public void add(int part, long init, long updatesCnt) {
         ensureSpace(size + 1);
@@ -131,6 +135,15 @@ public void add(int part, long init, long updatesCnt) {
         GridUnsafe.putLong(data, off, updatesCnt);
     }
 
+    /** Optimizes the memory used after adding counters with {@link #add(int, long, long)}. */
+    public void finishUpdating() {
+        if (data != null && data.length != size * ITEM_SIZE) {
+            assert data.length > size * ITEM_SIZE;
+
+            data = Arrays.copyOf(data, size * ITEM_SIZE);
+        }
+    }
+
     /**
      * Calculate next counter for partition.
      *
@@ -158,10 +171,9 @@ private void ensureSpace(int newSize) {
         int req = newSize * ITEM_SIZE;
 
         if (data.length < req)
-            data = Arrays.copyOf(data, data.length << 1);
+            data = Arrays.copyOf(data, (int)(data.length * 1.33f));
     }
 
-
     /** {@inheritDoc} */
     @Override public String toString() {
         StringBuilder sb = new StringBuilder();
@@ -182,14 +194,4 @@ private void ensureSpace(int newSize) {
             ", cntrs=" + sb +
             '}';
     }
-
-    /** {@inheritDoc} */
-    @Override public void prepareMarshal(Marshaller marsh) throws IgniteCheckedException {
-        data = Arrays.copyOf(data, size * ITEM_SIZE);
-    }
-
-    /** {@inheritDoc} */
-    @Override public void finishUnmarshal(Marshaller marsh, ClassLoader clsLdr) throws IgniteCheckedException {
-        size = data == null ? 0 : data.length / ITEM_SIZE;
-    }
 }
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/transactions/IgniteTxHandler.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/transactions/IgniteTxHandler.java
index 10f38a3d105e1..392f37d32b060 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/transactions/IgniteTxHandler.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/transactions/IgniteTxHandler.java
@@ -2197,6 +2197,8 @@ public void applyPartitionsUpdatesCounters(
                     resCntrs.add(part, partCntrs.initialCounter(i), partCntrs.updatesCount(i));
             }
 
+            resCntrs.finishUpdating();
+
             if (resCntrs.size() > 0)
                 res.add(resCntrs);
         }
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/transactions/IgniteTxLocalAdapter.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/transactions/IgniteTxLocalAdapter.java
index 71c79fe8f9bac..bf2ea8938c245 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/transactions/IgniteTxLocalAdapter.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/transactions/IgniteTxLocalAdapter.java
@@ -475,6 +475,8 @@ public void calculatePartitionUpdateCounters() throws IgniteTxRollbackCheckedExc
                     }
                 }
 
+                msg.finishUpdating();
+
                 if (msg.size() > 0)
                     cntrMsgs.add(msg);
             }