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Posted to commits@ignite.apache.org by sb...@apache.org on 2017/08/30 15:07:01 UTC

[2/3] ignite git commit: ignite-3478

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/MvccTestApp2.java
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diff --git a/modules/core/src/main/java/org/apache/ignite/internal/MvccTestApp2.java b/modules/core/src/main/java/org/apache/ignite/internal/MvccTestApp2.java
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@@ -0,0 +1,1708 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.ignite.internal;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+import java.util.TreeSet;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ConcurrentSkipListMap;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+import org.apache.ignite.internal.processors.cache.KeyCacheObject;
+import org.apache.ignite.internal.util.GridAtomicLong;
+import org.apache.ignite.internal.util.tostring.GridToStringInclude;
+import org.apache.ignite.internal.util.typedef.internal.S;
+import org.apache.ignite.internal.util.typedef.internal.U;
+import org.jetbrains.annotations.NotNull;
+import org.jsr166.ConcurrentHashMap8;
+
+/**
+ *
+ */
+public class MvccTestApp2 {
+    /** */
+    private static final boolean DEBUG_LOG = false;
+
+    /** */
+    private static final boolean SQL = false;
+
+    public static void main1(String[] args) throws Exception {
+        final TestCluster cluster = new TestCluster(1);
+
+        final int ACCOUNTS = 3;
+
+        final int START_VAL = 10;
+
+        final Map<Object, Object> data = new TreeMap<>();
+
+        for (int i = 0; i < ACCOUNTS; i++)
+            data.put(i, START_VAL);
+
+        cluster.txPutAll(data);
+
+        cluster.txTransfer(0, 1, true);
+        cluster.txTransfer(0, 1, true);
+        cluster.txTransfer(0, 2, true);
+
+        Map<Object, Object> vals = cluster.sqlAll();
+
+        System.out.println();
+
+        Map<Object, Object> getData = cluster.sqlAll();;//cluster.getAll(data.keySet());
+
+        int sum = 0;
+
+        for (int i = 0; i < ACCOUNTS; i++) {
+            Integer val = (Integer)getData.get(i);
+
+            sum += val;
+
+            System.out.println("Val: " + val);
+        }
+
+        System.out.println("Sum: " + sum);
+
+        cluster.cleanup();
+
+        getData = cluster.sqlAll();
+
+        System.out.println();
+//
+//        MvccQueryVersion ver1 = cluster.crd.queryVersion();
+//        MvccQueryVersion ver2 = cluster.crd.queryVersion();
+//
+//        cluster.crd.queryDone(ver2.cntr);
+//        cluster.crd.queryDone(ver1.cntr);
+    }
+
+    public static void main0(String[] args) throws Exception {
+        final TestCluster cluster = new TestCluster(1);
+
+        final int ACCOUNTS = 3;
+
+        final int START_VAL = 10;
+
+        final Map<Object, Object> data = new TreeMap<>();
+
+        for (int i = 0; i < ACCOUNTS; i++)
+            data.put(i, START_VAL);
+
+        cluster.txPutAll(data);
+
+        cluster.txRemoveTransfer(0, 1);
+
+        Map<Object, Object> getData = cluster.sqlAll();;//cluster.getAll(data.keySet());
+
+        int sum = 0;
+
+        for (Map.Entry<Object, Object> e : getData.entrySet()) {
+            Integer val = (Integer)e.getValue();
+
+            if (val != null)
+                sum += val;
+
+            System.out.println("Val: " + val);
+        }
+
+        System.out.println("Sum: " + sum);
+
+        cluster.cleanup();
+
+        getData = cluster.sqlAll();
+
+        System.out.println();
+//
+//        MvccQueryVersion ver1 = cluster.crd.queryVersion();
+//        MvccQueryVersion ver2 = cluster.crd.queryVersion();
+//
+//        cluster.crd.queryDone(ver2.cntr);
+//        cluster.crd.queryDone(ver1.cntr);
+    }
+
+    public static void main(String[] args) throws Exception {
+        final AtomicBoolean err = new AtomicBoolean();
+
+        final int READ_THREADS = 4;
+        final int UPDATE_THREADS = 4;
+        final int ACCOUNTS = 50;
+
+        final int START_VAL = 100000;
+
+        for (int iter = 0; iter < 1000; iter++) {
+            System.out.println("Iteration [readThreads=" + READ_THREADS +
+                ", updateThreads=" + UPDATE_THREADS + ", accounts=" + ACCOUNTS + ", iter=" + iter + ']');
+
+            final TestCluster cluster = new TestCluster(1);
+
+            final Map<Object, Object> data = new TreeMap<>();
+
+            for (int i = 0; i < ACCOUNTS; i++)
+                data.put(i, START_VAL);
+
+            cluster.txPutAll(data);
+
+            final AtomicBoolean stop = new AtomicBoolean();
+
+            List<Thread> threads = new ArrayList<>();
+
+            Thread cleanupThread = new Thread(new Runnable() {
+                @Override public void run() {
+                    Thread.currentThread().setName("cleanup");
+
+                    try {
+                        while (!stop.get()) {
+                            cluster.cleanup();
+
+                            Thread.sleep(1);
+                        }
+                    }
+                    catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
+            });
+
+            threads.add(cleanupThread);
+
+            cleanupThread.start();
+
+            final boolean REMOVES = false;
+
+            for (int i = 0; i < READ_THREADS; i++) {
+                final int id = i;
+
+                Thread thread = new Thread(new Runnable() {
+                    @Override public void run() {
+                        Thread.currentThread().setName("read" + id);
+
+                        int cnt = 0;
+
+                        while (!stop.get()) {
+                            Map<Object, Object> qryData = SQL ? cluster.sqlAll() : cluster.getAll(data.keySet());
+
+                            cnt++;
+
+                            int sum = 0;
+
+                            if (REMOVES) {
+                                for (Map.Entry<Object, Object> e : qryData.entrySet()) {
+                                    Integer val = (Integer)e.getValue();
+
+                                    if (val != null)
+                                        sum += val;
+                                    else
+                                        System.out.println("With null");
+                                }
+                            }
+                            else {
+                                for (int i = 0; i < ACCOUNTS; i++) {
+                                    Integer val = (Integer)qryData.get(i);
+
+                                    if (val == null) {
+                                        if (stop.compareAndSet(false, true)) {
+                                            stop.set(true);
+                                            err.set(true);
+
+                                            TestDebugLog.printAllAndExit("No value for key: " + i);
+                                        }
+
+                                        return;
+                                    }
+
+                                    sum += val;
+                                }
+                            }
+
+                            if (sum != ACCOUNTS * START_VAL) {
+                                if (stop.compareAndSet(false, true)) {
+                                    stop.set(true);
+                                    err.set(true);
+
+                                    TestDebugLog.printAllAndExit("Invalid get sum: " + sum);
+                                }
+                            }
+
+//                            if (cnt % 100 == 0)
+//                                System.out.println("get " + cnt);
+                        }
+
+                        System.out.println("Get cnt: " + cnt);
+                    }
+                });
+
+                threads.add(thread);
+
+                thread.start();
+            }
+
+            for (int i = 0; i < UPDATE_THREADS; i++) {
+                final int id = i;
+
+                Thread thread;
+
+                if (REMOVES) {
+                    thread = new Thread(new Runnable() {
+                        @Override public void run() {
+                            Thread.currentThread().setName("update" + id);
+
+                            ThreadLocalRandom rnd = ThreadLocalRandom.current();
+
+                            while (!stop.get()) {
+                                int id1 = rnd.nextInt(ACCOUNTS);
+
+                                int id2 = rnd.nextInt(ACCOUNTS);
+
+                                while (id2 == id1)
+                                    id2 = rnd.nextInt(ACCOUNTS);
+
+                                if (rnd.nextBoolean()) {
+                                    cluster.txRemoveTransfer(id1, id2);
+                                }
+                                else
+                                    cluster.txTransfer(id1, id2, rnd.nextBoolean());
+                            }
+
+                        }
+                    });
+                }
+                else {
+                    thread = new Thread(new Runnable() {
+                        @Override public void run() {
+                            Thread.currentThread().setName("update" + id);
+
+                            ThreadLocalRandom rnd = ThreadLocalRandom.current();
+
+                            while (!stop.get()) {
+                                int id1 = rnd.nextInt(ACCOUNTS);
+
+                                int id2 = rnd.nextInt(ACCOUNTS);
+
+                                while (id2 == id1)
+                                    id2 = rnd.nextInt(ACCOUNTS);
+
+                                if (id1 > id2) {
+                                    int tmp = id1;
+                                    id1 = id2;
+                                    id2 = tmp;
+                                }
+
+                                cluster.txTransfer(id1, id2, rnd.nextBoolean());
+                            }
+
+                        }
+                    });
+                }
+
+                threads.add(thread);
+
+                thread.start();
+            }
+
+            long endTime = System.currentTimeMillis() + 2_000;
+
+            while (!stop.get()) {
+                Thread.sleep(1000);
+
+                if (System.currentTimeMillis() >= endTime)
+                    break;
+
+                //cluster.dumpMvccInfo();
+            }
+
+            stop.set(true);
+
+            for (Thread thread : threads)
+                thread.join();
+
+            Map<Object, Object> qryData = SQL ? cluster.sqlAll() : cluster.getAll(data.keySet());
+
+            int sum = 0;
+
+            for (int i = 0; i < ACCOUNTS; i++) {
+                Integer val = (Integer)qryData.get(i);
+
+                System.out.println("Val " + val);
+
+                if (val != null)
+                    sum += val;
+            }
+
+            System.out.println("Sum=" + sum + ", expSum=" + (ACCOUNTS * START_VAL));
+
+            if (err.get()) {
+                System.out.println("Error!");
+
+                System.exit(1);
+            }
+
+//            cluster.dumpMvccInfo();
+//
+//            System.out.println("Cleanup");
+//
+//            cluster.cleanup();
+//
+//            cluster.dumpMvccInfo();
+
+            TestDebugLog.clear();
+        }
+    }
+
+    /**
+     *
+     */
+    static class TestCluster {
+        /** */
+        final List<Node> nodes = new ArrayList<>();
+
+        /** */
+        final Coordinator crd;
+
+        /** */
+        final AtomicLong txIdGen = new AtomicLong(10_000);
+
+        TestCluster(int nodesNum) {
+            crd = new Coordinator();
+
+            for (int i = 0; i < nodesNum; i++)
+                nodes.add(new Node(i));
+        }
+
+        void cleanup() {
+            CoordinatorCounter cntr = crd.cleanupVersion();
+
+            for (Node node : nodes)
+                node.dataStore.cleanup(cntr);
+        }
+
+        void txPutAll(Map<Object, Object> data) {
+            TxId txId = new TxId(txIdGen.incrementAndGet());
+
+            Map<Object, Node> mappedEntries = new LinkedHashMap<>();
+
+            for (Object key : data.keySet()) {
+                int nodeIdx = nodeForKey(key);
+
+                Node node = nodes.get(nodeIdx);
+
+                node.dataStore.lockEntry(key);
+
+                mappedEntries.put(key, node);
+            }
+
+            CoordinatorCounter cntr = crd.nextTxCounter(txId);
+
+            MvccUpdateVersion mvccVer = new MvccUpdateVersion(cntr, txId);
+
+            for (Map.Entry<Object, Node> e : mappedEntries.entrySet()) {
+                Node node = e.getValue();
+
+                node.dataStore.updateEntry(e.getKey(), data.get(e.getKey()), mvccVer);
+            }
+
+            for (Map.Entry<Object, Node> e : mappedEntries.entrySet()) {
+                Node node = e.getValue();
+
+                node.dataStore.unlockEntry(e.getKey());
+            }
+
+            crd.txDone(txId, cntr.cntr);
+        }
+
+        void txTransfer(Integer id1, Integer id2, boolean fromFirst) {
+            TreeSet<Integer> keys = new TreeSet<>();
+
+            keys.add(id1);
+            keys.add(id2);
+
+            TxId txId = new TxId(txIdGen.incrementAndGet());
+
+            Map<Object, Node> mappedEntries = new LinkedHashMap<>();
+
+            Map<Object, Object> vals = new HashMap<>();
+
+            for (Object key : keys) {
+                int nodeIdx = nodeForKey(key);
+
+                Node node = nodes.get(nodeIdx);
+
+                node.dataStore.lockEntry(key);
+
+                vals.put(key, node.dataStore.lastValue(key));
+
+                mappedEntries.put(key, node);
+            }
+
+            CoordinatorCounter cntr = crd.nextTxCounter(txId);
+
+            Integer curVal1 = (Integer)vals.get(id1);
+            Integer curVal2 = (Integer)vals.get(id2);
+
+            boolean update = false;
+
+            Integer newVal1 = null;
+            Integer newVal2 = null;
+
+            if (curVal1 != null && curVal2 != null) {
+                if (fromFirst) {
+                    if (curVal1 > 0) {
+                        update = true;
+
+                        newVal1 = curVal1 - 1;
+                        newVal2 = curVal2 + 1;
+                    }
+                }
+                else {
+                    if (curVal2 > 0) {
+                        update = true;
+
+                        newVal1 = curVal1 + 1;
+                        newVal2 = curVal2 - 1;
+                    }
+                }
+            }
+
+            if (update) {
+                Map<Object, Object> newVals = new HashMap<>();
+
+                newVals.put(id1, newVal1);
+                newVals.put(id2, newVal2);
+
+                MvccUpdateVersion mvccVer = new MvccUpdateVersion(cntr, txId);
+
+                if (DEBUG_LOG) {
+                    TestDebugLog.msgs.add(new TestDebugLog.Msg6("update", txId, id1, newVal1, id2, newVal2, cntr));
+                }
+
+                for (Map.Entry<Object, Node> e : mappedEntries.entrySet()) {
+                    Node node = e.getValue();
+
+                    node.dataStore.updateEntry(e.getKey(), newVals.get(e.getKey()), mvccVer);
+                }
+
+                for (Map.Entry<Object, Node> e : mappedEntries.entrySet()) {
+                    Node node = e.getValue();
+
+                    node.dataStore.unlockEntry(e.getKey());
+                }
+            }
+            else {
+                for (Map.Entry<Object, Node> e : mappedEntries.entrySet()) {
+                    Node node = e.getValue();
+
+                    node.dataStore.unlockEntry(e.getKey());
+                }
+            }
+
+            crd.txDone(txId, cntr.cntr);
+
+//            if (DEBUG_LOG)
+//                TestDebugLog.msgs.add(new TestDebugLog.Msg2("tx done", txId, cntr.cntr));
+        }
+
+        void txRemoveTransfer(Integer from, Integer to) {
+            TreeSet<Integer> keys = new TreeSet<>();
+
+            keys.add(from);
+            keys.add(to);
+
+            TxId txId = new TxId(txIdGen.incrementAndGet());
+
+            Map<Object, Node> mappedEntries = new LinkedHashMap<>();
+
+            Map<Object, Object> vals = new HashMap<>();
+
+            for (Object key : keys) {
+                int nodeIdx = nodeForKey(key);
+
+                Node node = nodes.get(nodeIdx);
+
+                node.dataStore.lockEntry(key);
+
+                vals.put(key, node.dataStore.lastValue(key));
+
+                mappedEntries.put(key, node);
+            }
+
+            CoordinatorCounter cntr = crd.nextTxCounter(txId);
+
+            Integer fromVal = (Integer)vals.get(from);
+            Integer toVal = (Integer)vals.get(to);
+
+            boolean update = fromVal != null && toVal != null;
+
+            if (update) {
+                Map<Object, Object> newVals = new HashMap<>();
+
+                newVals.put(from, null);
+                newVals.put(to, fromVal + toVal);
+
+                MvccUpdateVersion mvccVer = new MvccUpdateVersion(cntr, txId);
+
+                if (DEBUG_LOG) {
+                    TestDebugLog.msgs.add(new TestDebugLog.Msg6("remove", txId, from, fromVal, to, toVal, cntr));
+                }
+
+                for (Map.Entry<Object, Node> e : mappedEntries.entrySet()) {
+                    Node node = e.getValue();
+
+                    node.dataStore.updateEntry(e.getKey(), newVals.get(e.getKey()), mvccVer);
+                }
+
+                for (Map.Entry<Object, Node> e : mappedEntries.entrySet()) {
+                    Node node = e.getValue();
+
+                    node.dataStore.unlockEntry(e.getKey());
+                }
+            }
+            else {
+                for (Map.Entry<Object, Node> e : mappedEntries.entrySet()) {
+                    Node node = e.getValue();
+
+                    node.dataStore.unlockEntry(e.getKey());
+                }
+            }
+
+            crd.txDone(txId, cntr.cntr);
+
+            if (DEBUG_LOG)
+                TestDebugLog.msgs.add(new TestDebugLog.Msg2("tx done", txId, cntr.cntr));
+        }
+
+        public void dumpMvccInfo() {
+            for (Node node : nodes) {
+                int sql = node.dataStore.mvccSqlIdx.size();
+
+                for (Map.Entry<Object, MvccValue> e : node.dataStore.mainIdx.entrySet()) {
+                    List<MvccValue> list = node.dataStore.mvccIdx.get(e.getKey());
+
+                    int size = 0;
+
+                    if (list != null) {
+                        synchronized (list) {
+                            size = list.size();
+                        }
+                    }
+
+                    System.out.println("Mvcc info [key=" + e.getKey() +
+                        ", val=" + e.getValue() +
+                        ", mvccVals=" + size +
+                        ", sqlVals=" + sql + ']');
+                }
+            }
+        }
+
+        public Map<Object, Object> sqlAll() {
+            MvccQueryVersion qryVer = crd.queryVersion();
+
+            Map<Object, Object> res = new HashMap<>();
+
+            for (Node node : nodes) {
+                Map<Object, Object> nodeRes = node.dataStore.sqlQuery(qryVer);
+
+                res.putAll(nodeRes);
+            }
+
+            crd.queryDone(qryVer.cntr);
+
+            if (DEBUG_LOG) {
+                TestDebugLog.msgs.add(new TestDebugLog.Msg3("sqlAll", qryVer.cntr, qryVer.activeTxs, res));
+            }
+
+            return res;
+        }
+
+        public Map<Object, Object> getAll(Set<?> keys) {
+            MvccQueryVersion qryVer = crd.queryVersion();
+
+            Map<Object, Object> res = new HashMap<>();
+
+            for (Object key : keys) {
+                int nodeIdx = nodeForKey(key);
+
+                Node node = nodes.get(nodeIdx);
+
+                Object val = node.dataStore.get(key, qryVer);
+
+                res.put(key, val);
+            }
+
+            crd.queryDone(qryVer.cntr);
+
+            if (DEBUG_LOG) {
+                TestDebugLog.msgs.add(new TestDebugLog.Msg3("getAll", qryVer.cntr, qryVer.activeTxs, res));
+            }
+
+            return res;
+        }
+
+        private int nodeForKey(Object key) {
+            return U.safeAbs(key.hashCode()) % nodes.size();
+        }
+    }
+
+    /**
+     *
+     */
+    static class Node {
+        /** */
+        final DataStore dataStore;
+
+        /** */
+        final int nodexIdx;
+
+        public Node(int nodexIdx) {
+            this.nodexIdx = nodexIdx;
+
+            dataStore = new DataStore();
+        }
+
+        @Override public String toString() {
+            return "Node [idx=" + nodexIdx + ']';
+        }
+    }
+
+    /**
+     *
+     */
+    static class Coordinator {
+        /** */
+        private final AtomicLong cntr = new AtomicLong(-1);
+
+        /** */
+        private final GridAtomicLong commitCntr = new GridAtomicLong(-1);
+
+        /** */
+        private final ConcurrentHashMap8<Long, QueryCounter> activeQueries = new ConcurrentHashMap8<>();
+
+        /** */
+        @GridToStringInclude
+        private final ConcurrentHashMap8<TxId, Long> activeTxs = new ConcurrentHashMap8<>();
+
+        CoordinatorCounter nextTxCounter(TxId txId) {
+            long cur = cntr.get();
+
+            activeTxs.put(txId, cur + 1);
+
+            CoordinatorCounter newCtr = new CoordinatorCounter(cntr.incrementAndGet());
+
+            return newCtr;
+        }
+
+        void txDone(TxId txId, long cntr) {
+            Long rmvd = activeTxs.remove(txId);
+
+            assert rmvd != null;
+
+            commitCntr.setIfGreater(cntr);
+        }
+
+        private GridAtomicLong minActive0 = new GridAtomicLong(0);
+
+        private Long minActive(Set<TxId> txs) {
+            Long minActive = null;
+
+            for (Map.Entry<TxId, Long> e : activeTxs.entrySet()) {
+                if (txs != null)
+                    txs.add(e.getKey());
+
+//                TxId val = e.getValue();
+//
+//                while (val.cntr == -1)
+//                    Thread.yield();
+
+                long cntr = e.getValue();
+
+                if (minActive == null)
+                    minActive = cntr;
+                else if (cntr < minActive)
+                    minActive = cntr;
+            }
+
+            if (minActive != null) {
+                if (!minActive0.setIfGreater(minActive))
+                    return minActive0.get();
+            }
+
+            return minActive;
+        }
+
+        static class QueryCounter extends AtomicInteger {
+            public QueryCounter(int initialValue) {
+                super(initialValue);
+            }
+
+            boolean increment2() {
+                for (;;) {
+                    int current = get();
+                    int next = current + 1;
+
+                    if (current == 0)
+                        return false;
+
+                    if (compareAndSet(current, next))
+                        return true;
+                }
+            }
+        }
+
+        private ReadWriteLock rwLock = new ReentrantReadWriteLock();
+
+        MvccQueryVersion queryVersion() {
+            rwLock.readLock().lock();
+
+            long useCntr = commitCntr.get();
+
+            Set<TxId> txs = new HashSet<>();
+
+            Long minActive = minActive(txs);
+
+            if (minActive != null && minActive < useCntr)
+                useCntr = minActive - 1;
+
+            MvccQueryVersion qryVer = new MvccQueryVersion(new CoordinatorCounter(useCntr), txs);
+
+            for (;;) {
+                QueryCounter qryCnt = activeQueries.get(useCntr);
+
+                if (qryCnt != null) {
+                    boolean inc = qryCnt.increment2();
+
+                    if (!inc) {
+                        activeQueries.remove(useCntr, qryCnt);
+
+                        continue;
+                    }
+                }
+                else {
+                    qryCnt = new QueryCounter(1);
+
+                    if (activeQueries.putIfAbsent(useCntr, qryCnt) != null)
+                        continue;
+                }
+
+                break;
+            }
+
+            rwLock.readLock().unlock();
+
+            return qryVer;
+        }
+
+        void queryDone(CoordinatorCounter cntr) {
+            AtomicInteger qryCnt = activeQueries.get(cntr.cntr);
+
+            assert qryCnt != null : cntr.cntr;
+
+            int left = qryCnt.decrementAndGet();
+
+            assert left >= 0 : left;
+
+            if (left == 0)
+                activeQueries.remove(cntr.cntr, qryCnt);
+        }
+
+        CoordinatorCounter cleanupVersion() {
+            rwLock.writeLock().lock();
+
+            long useCntr = commitCntr.get();
+
+            Long minActive = minActive(null);
+
+            if (minActive != null && minActive < useCntr)
+                useCntr = minActive - 1;
+
+            for (Long qryCntr : activeQueries.keySet()) {
+                if (qryCntr <= useCntr)
+                    useCntr = qryCntr - 1;
+            }
+
+            rwLock.writeLock().unlock();
+
+            return new CoordinatorCounter(useCntr);
+        }
+
+        @Override public String toString() {
+            return S.toString(Coordinator.class, this);
+        }
+    }
+
+    /**
+     *
+     */
+    static class CoordinatorCounter implements Comparable<CoordinatorCounter> {
+        /** */
+        private final long topVer; // TODO
+
+        /** */
+        private final long cntr;
+
+        CoordinatorCounter(long cntr) {
+            this.topVer = 1;
+            this.cntr = cntr;
+        }
+
+        @Override public int compareTo(CoordinatorCounter o) {
+            return Long.compare(cntr, o.cntr);
+        }
+
+        @Override public boolean equals(Object o) {
+            if (this == o)
+                return true;
+
+            if (o == null || getClass() != o.getClass())
+                return false;
+
+            CoordinatorCounter that = (CoordinatorCounter)o;
+
+            return cntr == that.cntr;
+        }
+
+        @Override public int hashCode() {
+            return (int)(cntr ^ (cntr >>> 32));
+        }
+
+        @Override public String toString() {
+            return "Cntr [c=" + cntr + ']';
+        }
+    }
+
+    /**
+     *
+     */
+    static class MvccUpdateVersion {
+        /** */
+        @GridToStringInclude
+        final CoordinatorCounter cntr;
+
+        /** */
+        @GridToStringInclude
+        final TxId txId;
+
+        /**
+         * @param cntr
+         */
+        MvccUpdateVersion(CoordinatorCounter cntr, TxId txId) {
+            assert cntr != null;
+
+            this.cntr = cntr;
+            this.txId = txId;
+        }
+
+        @Override public String toString() {
+            return S.toString(MvccUpdateVersion.class, this);
+        }
+    }
+
+    /**
+     *
+     */
+    static class MvccQueryVersion {
+        /** */
+        @GridToStringInclude
+        final CoordinatorCounter cntr;
+
+        /** */
+        @GridToStringInclude
+        final Collection<TxId> activeTxs;
+
+        MvccQueryVersion(CoordinatorCounter cntr, Collection<TxId> activeTxs) {
+            this.cntr = cntr;
+            this.activeTxs = activeTxs;
+        }
+
+        @Override public String toString() {
+            return S.toString(MvccQueryVersion.class, this);
+        }
+    }
+
+    /**
+     *
+     */
+    static class TxId {
+        /** */
+        @GridToStringInclude
+        final long id;
+
+        TxId(long id) {
+            this.id = id;
+        }
+
+        @Override public boolean equals(Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+
+            TxId txId = (TxId) o;
+
+            return id == txId.id;
+        }
+
+        @Override public int hashCode() {
+            return (int) (id ^ (id >>> 32));
+        }
+
+        @Override public String toString() {
+            return S.toString(TxId.class, this);
+        }
+    }
+
+    /**
+     *
+     */
+    static class SqlKey implements Comparable<SqlKey> {
+        /** */
+        final Comparable key;
+
+        /** */
+        final Comparable val;
+
+        /** */
+        final CoordinatorCounter cntr;
+
+        public SqlKey(Object key, Object val, CoordinatorCounter cntr) {
+            this.key = (Comparable)key;
+            this.val = (Comparable)val;
+            this.cntr = cntr;
+        }
+
+        @Override public int compareTo(@NotNull SqlKey o) {
+            int cmp;
+
+            if (val != null && o.val != null)
+                cmp = val.compareTo(o.val);
+            else {
+                if (val != null)
+                    cmp = 1;
+                else
+                    cmp = o.val == null ? 0 : -1;
+            }
+
+
+            if (cmp == 0) {
+                cmp = key.compareTo(o.key);
+
+                if (cmp == 0)
+                    cmp = cntr.compareTo(o.cntr);
+            }
+
+            return cmp;
+        }
+
+        @Override public String toString() {
+            return "SqlKey [key=" + key + ", val=" + val + ']';
+        }
+    }
+
+    /**
+     *
+     */
+    static class DataStore {
+        /** */
+        private final ConcurrentHashMap<Object, ReentrantLock> locks = new ConcurrentHashMap<>();
+
+        /** */
+        final ConcurrentHashMap<Object, MvccValue> mainIdx = new ConcurrentHashMap<>();
+
+        /** */
+        final ConcurrentHashMap<Object, List<MvccValue>> mvccIdx = new ConcurrentHashMap<>();
+
+        /** */
+        final ConcurrentSkipListMap<SqlKey, MvccSqlValue> mvccSqlIdx = new ConcurrentSkipListMap<>();
+
+        void cleanup(CoordinatorCounter cleanupCntr) {
+            for (Map.Entry<Object, List<MvccValue>> e : mvccIdx.entrySet()) {
+                lockEntry(e.getKey());
+
+                try {
+                    List<MvccValue> list = e.getValue();
+
+                    synchronized (list) {
+                        for (int i = list.size() - 1; i >= 0; i--) {
+                            MvccValue val = list.get(i);
+
+                            if (val.ver.cntr.compareTo(cleanupCntr) <= 0) {
+                                if (DEBUG_LOG) {
+                                    TestDebugLog.msgs.add(new TestDebugLog.Msg6_1("cleanup",
+                                        e.getKey(), val.val, val.ver, cleanupCntr.cntr, null, null));
+                                }
+
+                                MvccValue prev;
+
+                                if (val.val != null)
+                                    prev = mainIdx.put(e.getKey(), val);
+                                else
+                                    prev = mainIdx.remove(e.getKey());
+
+                                if (prev != null) {
+                                    SqlKey key = new SqlKey(e.getKey(), prev.val, prev.ver.cntr);
+
+                                    MvccSqlValue old = mvccSqlIdx.remove(key);
+
+                                    assert old != null;
+                                }
+
+                                for (int j = 0; j <= i; j++) {
+                                    MvccValue rmvd = list.remove(0);
+
+                                    assert rmvd != null;
+
+                                    if (j != i || rmvd.val == null) {
+                                        SqlKey key = new SqlKey(e.getKey(), rmvd.val, rmvd.ver.cntr);
+
+                                        MvccSqlValue old = mvccSqlIdx.remove(key);
+
+                                        assert old != null;
+                                    }
+                                }
+
+                                if (list.isEmpty())
+                                    mvccIdx.remove(e.getKey());
+
+                                break;
+                            }
+                        }
+                    }
+                }
+                finally {
+                    unlockEntry(e.getKey());
+                }
+            }
+        }
+
+        void lockEntry(Object key) {
+            ReentrantLock e = lock(key);
+
+            e.lock();
+        }
+
+        void unlockEntry(Object key) {
+            ReentrantLock e = lock(key);
+
+            e.unlock();
+        }
+
+        void updateEntry(Object key, Object val, MvccUpdateVersion ver) {
+            List<MvccValue> list = mvccIdx.get(key);
+
+            if (list == null) {
+                Object old = mvccIdx.putIfAbsent(key, list = new ArrayList<>());
+
+                assert old == null;
+            }
+
+            MvccValue prevVal = null;
+
+            synchronized (list) {
+                if (!list.isEmpty())
+                    prevVal = list.get(list.size() - 1);
+
+                list.add(new MvccValue(val, ver));
+            }
+
+            if (prevVal == null)
+                prevVal = mainIdx.get(key);
+
+            if (prevVal != null) {
+                SqlKey prevKey = new SqlKey(key, prevVal.val, prevVal.ver.cntr);
+
+                MvccSqlValue old =
+                    mvccSqlIdx.put(prevKey, new MvccSqlValue(prevVal.val, prevVal.ver, ver));
+
+                assert old != null;
+            }
+
+            mvccSqlIdx.put(new SqlKey(key, val, ver.cntr), new MvccSqlValue(val, ver, null));
+        }
+
+        Object lastValue(Object key) {
+            List<MvccValue> list = mvccIdx.get(key);
+
+            if (list != null) {
+                synchronized (list) {
+                    if (list.size() > 0)
+                        return list.get(list.size() - 1).val;
+                }
+            }
+
+            MvccValue val = mainIdx.get(key);
+
+            return val != null ? val.val : null;
+        }
+
+        Map<Object, Object> sqlQuery(MvccQueryVersion qryVer) {
+            Map<Object, Object> res = new HashMap<>();
+
+            for (Map.Entry<SqlKey, MvccSqlValue> e : mvccSqlIdx.entrySet()) {
+                MvccSqlValue val = e.getValue();
+
+                if (!versionVisible(val.ver, qryVer)) {
+                    if (DEBUG_LOG) {
+                        TestDebugLog.msgs.add(new TestDebugLog.Msg3("sql skip mvcc val", e.getKey().key, val.val, val.ver));
+                    }
+
+                    continue;
+                }
+
+                MvccUpdateVersion newVer = val.newVer;
+
+                if (newVer != null && versionVisible(newVer, qryVer)) {
+                    if (DEBUG_LOG) {
+                        TestDebugLog.msgs.add(new TestDebugLog.Msg4("sql skip mvcc val2", e.getKey().key, val.val, val.ver, val.newVer));
+                    }
+
+                    continue;
+                }
+
+                Object old = res.put(e.getKey().key, e.getValue().val);
+
+                if (DEBUG_LOG) {
+                    //TestDebugLog.msgs.add(new TestDebugLog.Msg4("sql get mvcc val", e.getKey().key, val.val, val.ver, val.newVer));
+                }
+
+                if (old != null) {
+                    TestDebugLog.printAllAndExit("Already has value for key [key=" + e.getKey().key +
+                        ", qryVer=" + qryVer +
+                        ", oldVal=" + old +
+                        ", newVal=" + e.getValue().val +
+                        ']');
+                }
+
+                assert old == null;
+            }
+
+            return res;
+        }
+
+        private boolean versionVisible(MvccUpdateVersion ver, MvccQueryVersion qryVer) {
+            int cmp = ver.cntr.compareTo(qryVer.cntr);
+
+            return cmp <= 0;// && !qryVer.activeTxs.contains(ver.txId);
+        }
+
+        Object get(Object key, MvccQueryVersion ver) {
+            List<MvccValue> list = mvccIdx.get(key);
+
+            if (list != null) {
+                synchronized (list) {
+                    for (int i = list.size() - 1; i >= 0; i--) {
+                        MvccValue val = list.get(i);
+
+                        if (!versionVisible(val.ver, ver))
+                            continue;
+
+                        if (DEBUG_LOG) {
+                            TestDebugLog.msgs.add(new TestDebugLog.Msg3("read mvcc val", key, val.val, val.ver));
+                        }
+
+                        return val.val;
+                    }
+                }
+            }
+
+            MvccValue val = mainIdx.get(key);
+
+            if (val != null) {
+                int cmp = val.ver.cntr.compareTo(ver.cntr);
+
+                if (DEBUG_LOG) {
+                    if (cmp > 0) {
+                        synchronized (TestDebugLog.msgs) {
+                            TestDebugLog.msgs.add(new TestDebugLog.Message("Committed [key=" + key + ", ver=" + val.ver + ", qryVer=" + ver.cntr + ']'));
+
+                            TestDebugLog.printAllAndExit("Committed [key=" + key + ", ver=" + val.ver + ", qryVer=" + ver + ']');
+                        }
+                    }
+                }
+
+                assert cmp <= 0 : "Committed [ver=" + val.ver + ", qryVer=" + ver.cntr + ']';
+
+                if (DEBUG_LOG)
+                    TestDebugLog.msgs.add(new TestDebugLog.Msg3("read comitted val", key, val, val.ver));
+            }
+            else {
+                if (DEBUG_LOG)
+                    TestDebugLog.msgs.add(new TestDebugLog.Msg3("read comitted null", key, null, null));
+            }
+
+            return val != null ? val.val : null;
+        }
+
+        private ReentrantLock lock(Object key) {
+            ReentrantLock e = locks.get(key);
+
+            if (e == null) {
+                ReentrantLock old = locks.putIfAbsent(key, e = new ReentrantLock());
+
+                if (old != null)
+                    e = old;
+            }
+
+            return e;
+        }
+    }
+
+    /**
+     *
+     */
+    static class MvccValue {
+        /** */
+        @GridToStringInclude
+        final Object val;
+
+        /** */
+        @GridToStringInclude
+        final MvccUpdateVersion ver;
+
+        MvccValue(Object val, MvccUpdateVersion ver) {
+            assert ver != null;
+
+            this.val = val;
+            this.ver = ver;
+        }
+
+        @Override public String toString() {
+            return S.toString(MvccValue.class, this);
+        }
+    }
+
+    /**
+     *
+     */
+    static class MvccSqlValue {
+        /** */
+        @GridToStringInclude
+        final Object val;
+
+        /** */
+        @GridToStringInclude
+        final MvccUpdateVersion ver;
+
+        /** */
+        @GridToStringInclude
+        final MvccUpdateVersion newVer;
+
+        MvccSqlValue(Object val, MvccUpdateVersion ver, MvccUpdateVersion newVer) {
+            assert ver != null;
+
+            this.val = val;
+            this.ver = ver;
+            this.newVer = newVer;
+        }
+
+        @Override public String toString() {
+            return S.toString(MvccSqlValue.class, this);
+        }
+    }
+
+    static void log(String msg) {
+        System.out.println(Thread.currentThread() + ": " + msg);
+    }
+
+    static class TestDebugLog {
+        /** */
+        //static final List<Object> msgs = Collections.synchronizedList(new ArrayList<>(1_000_000));
+        static final ConcurrentLinkedQueue<Object> msgs = new ConcurrentLinkedQueue<>();
+
+
+
+        /** */
+        private static final SimpleDateFormat DEBUG_DATE_FMT = new SimpleDateFormat("HH:mm:ss,SSS");
+
+        static class Message {
+            String thread = Thread.currentThread().getName();
+
+            String msg;
+
+            long ts = U.currentTimeMillis();
+
+            public Message(String msg) {
+                this.msg = msg;
+            }
+
+            public String toString() {
+                return "Msg [msg=" + msg + ", thread=" + thread + ", time=" + DEBUG_DATE_FMT.format(new Date(ts)) + ']';
+            }
+        }
+
+        static class Msg2 extends Message{
+            Object v1;
+            Object v2;
+
+            public Msg2(String msg, Object v1, Object v2) {
+                super(msg);
+                this.v1 = v1;
+                this.v2 = v2;
+            }
+            public String toString() {
+                return "Msg [msg=" + msg +
+                    ", v1=" + v1 +
+                    ", v2=" + v2 +
+                    ", msg=" + msg +
+                    ", thread=" + thread +
+                    ", time=" + DEBUG_DATE_FMT.format(new Date(ts)) + ']';
+            }
+        }
+
+        static class Msg3 extends Message{
+            Object v1;
+            Object v2;
+            Object v3;
+
+            public Msg3(String msg, Object v1, Object v2, Object v3) {
+                super(msg);
+                this.v1 = v1;
+                this.v2 = v2;
+                this.v3 = v3;
+            }
+            public String toString() {
+                return "Msg [msg=" + msg +
+                    ", v1=" + v1 +
+                    ", v2=" + v2 +
+                    ", v3=" + v3 +
+                    ", thread=" + thread +
+                    ", time=" + DEBUG_DATE_FMT.format(new Date(ts)) + ']';
+            }
+        }
+
+        static class Msg4 extends Message{
+            Object v1;
+            Object v2;
+            Object v3;
+            Object v4;
+
+            public Msg4(String msg, Object v1, Object v2, Object v3, Object v4) {
+                super(msg);
+                this.v1 = v1;
+                this.v2 = v2;
+                this.v3 = v3;
+                this.v4 = v4;
+            }
+
+            public String toString() {
+                return "Msg [msg=" + msg +
+                    ", v1=" + v1 +
+                    ", v2=" + v2 +
+                    ", v3=" + v3 +
+                    ", v4=" + v4 +
+                    ", thread=" + thread +
+                    ", time=" + DEBUG_DATE_FMT.format(new Date(ts)) + ']';
+            }
+        }
+
+        static class Msg6 extends Message{
+            Object v1;
+            Object v2;
+            Object v3;
+            Object v4;
+            Object v5;
+            Object v6;
+
+            public Msg6(String msg, Object v1, Object v2, Object v3, Object v4, Object v5, Object v6) {
+                super(msg);
+                this.v1 = v1;
+                this.v2 = v2;
+                this.v3 = v3;
+                this.v4 = v4;
+                this.v5 = v5;
+                this.v6 = v6;
+            }
+
+            public String toString() {
+                return "Msg [msg=" + msg +
+                    ", txId=" + v1 +
+                    ", id1=" + v2 +
+                    ", v1=" + v3 +
+                    ", id2=" + v4 +
+                    ", v2=" + v5 +
+                    ", cntr=" + v6 +
+                    ", thread=" + thread +
+                    ", time=" + DEBUG_DATE_FMT.format(new Date(ts)) + ']';
+            }
+        }
+        static class Msg6_1 extends Message{
+            Object v1;
+            Object v2;
+            Object v3;
+            Object v4;
+            Object v5;
+            Object v6;
+
+            public Msg6_1(String msg, Object v1, Object v2, Object v3, Object v4, Object v5, Object v6) {
+                super(msg);
+                this.v1 = v1;
+                this.v2 = v2;
+                this.v3 = v3;
+                this.v4 = v4;
+                this.v5 = v5;
+                this.v6 = v6;
+            }
+
+            public String toString() {
+                return "Msg [msg=" + msg +
+                    ", key=" + v1 +
+                    ", val=" + v2 +
+                    ", ver=" + v3 +
+                    ", cleanupC=" + v4 +
+                    ", thread=" + thread +
+                    ", time=" + DEBUG_DATE_FMT.format(new Date(ts)) + ']';
+            }
+        }
+
+        static class EntryMessage extends Message {
+            Object key;
+            Object val;
+
+            public EntryMessage(Object key, Object val, String msg) {
+                super(msg);
+
+                this.key = key;
+                this.val = val;
+            }
+
+            public String toString() {
+                return "EntryMsg [key=" + key + ", val=" + val + ", msg=" + msg + ", thread=" + thread + ", time=" + DEBUG_DATE_FMT.format(new Date(ts)) + ']';
+            }
+        }
+
+        static class PartMessage extends Message {
+            int p;
+            Object val;
+
+            public PartMessage(int p, Object val, String msg) {
+                super(msg);
+
+                this.p = p;
+                this.val = val;
+            }
+
+            public String toString() {
+                return "PartMessage [p=" + p + ", val=" + val + ", msg=" + msg + ", thread=" + thread + ", time=" + DEBUG_DATE_FMT.format(new Date(ts)) + ']';
+            }
+        }
+
+        static final boolean out = false;
+
+        public static void addMessage(String msg) {
+            msgs.add(new Message(msg));
+
+            if (out)
+                System.out.println(msg);
+        }
+
+        public static void addEntryMessage(Object key, Object val, String msg) {
+            if (key instanceof KeyCacheObject)
+                key = ((KeyCacheObject)key).value(null, false);
+
+            EntryMessage msg0 = new EntryMessage(key, val, msg);
+
+            msgs.add(msg0);
+
+            if (out) {
+                System.out.println(msg0.toString());
+
+                System.out.flush();
+            }
+        }
+
+        public static void addPartMessage(int p, Object val, String msg) {
+            PartMessage msg0 = new PartMessage(p, val, msg);
+
+            msgs.add(msg0);
+
+            if (out) {
+                System.out.println(msg0.toString());
+
+                System.out.flush();
+            }
+        }
+
+        static void printAllAndExit(String msg) {
+            System.out.println(msg);
+
+            TestDebugLog.addMessage(msg);
+
+            List<Object> msgs = TestDebugLog.printMessages(true, null);
+
+            TestDebugLog.printMessages0(msgs, "test_debug_update.txt");
+
+            TestDebugLog.printMessagesForThread(msgs, Thread.currentThread().getName(), "test_debug_thread.txt");
+
+            System.exit(1);
+        }
+
+        public static void printMessagesForThread(List<Object> msgs0, String thread0, String file) {
+            try {
+                FileOutputStream out = new FileOutputStream(file);
+
+                PrintWriter w = new PrintWriter(out);
+
+                for (Object msg : msgs0) {
+                    if (msg instanceof Message) {
+                        String thread = ((Message) msg).thread;
+
+                        if (thread.equals(thread0))
+                            w.println(msg.toString());
+                    }
+                }
+
+                w.close();
+
+                out.close();
+            }
+            catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+
+        public static void printMessages0(List<Object> msgs0, String file) {
+            try {
+                FileOutputStream out = new FileOutputStream(file);
+
+                PrintWriter w = new PrintWriter(out);
+
+                for (Object msg : msgs0) {
+                    if (msg instanceof Message) {
+                        String msg0 = ((Message) msg).msg;
+
+                        if (msg0.equals("tx done") || msg0.equals("update") || msg0.equals("cleanup"))
+                            w.println(msg.toString());
+                    }
+                }
+
+                w.close();
+
+                out.close();
+            }
+            catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+
+        public static List<Object> printMessages(boolean file, Integer part) {
+            List<Object> msgs0;
+
+            synchronized (msgs) {
+                msgs0 = new ArrayList<>(msgs);
+
+                msgs.clear();
+            }
+
+            if (file) {
+                try {
+                    FileOutputStream out = new FileOutputStream("test_debug.log");
+
+                    PrintWriter w = new PrintWriter(out);
+
+                    for (Object msg : msgs0) {
+                        if (part != null && msg instanceof PartMessage) {
+                            if (((PartMessage) msg).p != part)
+                                continue;
+                        }
+
+                        w.println(msg.toString());
+                    }
+
+                    w.close();
+
+                    out.close();
+                }
+                catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+            else {
+                for (Object msg : msgs0)
+                    System.out.println(msg);
+            }
+
+            return msgs0;
+        }
+
+        public static void printKeyMessages(boolean file, Object key) {
+            List<Object> msgs0;
+
+            synchronized (msgs) {
+                msgs0 = new ArrayList<>(msgs);
+
+                msgs.clear();
+            }
+
+            if (file) {
+                try {
+                    FileOutputStream out = new FileOutputStream("test_debug.log");
+
+                    PrintWriter w = new PrintWriter(out);
+
+                    for (Object msg : msgs0) {
+                        if (msg instanceof EntryMessage && !((EntryMessage)msg).key.equals(key))
+                            continue;
+
+                        w.println(msg.toString());
+                    }
+
+                    w.close();
+
+                    out.close();
+                }
+                catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+            else {
+                for (Object msg : msgs0) {
+                    if (msg instanceof EntryMessage && !((EntryMessage)msg).key.equals(key))
+                        continue;
+
+                    System.out.println(msg);
+                }
+            }
+        }
+
+        public static void clear() {
+            msgs.clear();
+        }
+
+        public static void clearEntries() {
+            for (Iterator it = msgs.iterator(); it.hasNext();) {
+                Object msg = it.next();
+
+                if (msg instanceof EntryMessage)
+                    it.remove();
+            }
+        }
+
+    }}

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/managers/communication/GridIoMessageFactory.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/managers/communication/GridIoMessageFactory.java b/modules/core/src/main/java/org/apache/ignite/internal/managers/communication/GridIoMessageFactory.java
index 97e06bf..eae435e 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/managers/communication/GridIoMessageFactory.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/managers/communication/GridIoMessageFactory.java
@@ -102,6 +102,12 @@ import org.apache.ignite.internal.processors.cache.distributed.near.GridNearTxFi
 import org.apache.ignite.internal.processors.cache.distributed.near.GridNearTxPrepareRequest;
 import org.apache.ignite.internal.processors.cache.distributed.near.GridNearTxPrepareResponse;
 import org.apache.ignite.internal.processors.cache.distributed.near.GridNearUnlockRequest;
+import org.apache.ignite.internal.processors.cache.mvcc.CoordinatorMvccCounterResponse;
+import org.apache.ignite.internal.processors.cache.mvcc.CoordinatorQueryAckRequest;
+import org.apache.ignite.internal.processors.cache.mvcc.CoordinatorQueryCounterRequest;
+import org.apache.ignite.internal.processors.cache.mvcc.CoordinatorTxAckRequest;
+import org.apache.ignite.internal.processors.cache.mvcc.CoordinatorTxAckResponse;
+import org.apache.ignite.internal.processors.cache.mvcc.CoordinatorTxCounterRequest;
 import org.apache.ignite.internal.processors.cache.query.GridCacheQueryRequest;
 import org.apache.ignite.internal.processors.cache.query.GridCacheQueryResponse;
 import org.apache.ignite.internal.processors.cache.query.GridCacheSqlQuery;
@@ -875,6 +881,36 @@ public class GridIoMessageFactory implements MessageFactory {
 
                 break;
 
+            case 129:
+                msg = new CoordinatorTxCounterRequest();
+
+                break;
+
+            case 130:
+                msg = new CoordinatorMvccCounterResponse();
+
+                break;
+
+            case 131:
+                msg = new CoordinatorTxAckRequest();
+
+                break;
+
+            case 132:
+                msg = new CoordinatorTxAckResponse();
+
+                break;
+
+            case 133:
+                msg = new CoordinatorQueryCounterRequest();
+
+                break;
+
+            case 134:
+                msg = new CoordinatorQueryAckRequest();
+
+                break;
+
 
             // [-3..119] [124..128] [-23..-27] [-36..-55]- this
             // [120..123] - DR

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/ClusterCachesInfo.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/ClusterCachesInfo.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/ClusterCachesInfo.java
index 5e2c8db..19bd05d 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/ClusterCachesInfo.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/ClusterCachesInfo.java
@@ -237,6 +237,9 @@ class ClusterCachesInfo {
         CU.checkAttributeMismatch(log, rmtAttr.groupName(), rmt, "groupName", "Cache group name",
             locAttr.groupName(), rmtAttr.groupName(), true);
 
+        CU.checkAttributeMismatch(log, rmtAttr.cacheName(), rmt, "mvccEnabled", "MVCC mode",
+            locAttr.mvccEnabled(), rmtAttr.mvccEnabled(), true);
+
         if (rmtAttr.cacheMode() != LOCAL) {
             CU.checkAttributeMismatch(log, rmtAttr.cacheName(), rmt, "interceptor", "Cache Interceptor",
                 locAttr.interceptorClassName(), rmtAttr.interceptorClassName(), true);

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheAttributes.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheAttributes.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheAttributes.java
index d64ee8b..c1f03fa 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheAttributes.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheAttributes.java
@@ -329,6 +329,13 @@ public class GridCacheAttributes implements Serializable {
     }
 
     /**
+     * @return MVCC enabled flag.
+     */
+    public boolean mvccEnabled() {
+        return ccfg.isMvccEnabled();
+    }
+
+    /**
      * @param obj Object to get class of.
      * @return Class name or {@code null}.
      */

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheContext.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheContext.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheContext.java
index b6faf47..b504625 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheContext.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheContext.java
@@ -2033,6 +2033,13 @@ public class GridCacheContext<K, V> implements Externalizable {
     }
 
     /**
+     * @return {@code True} if mvcc is enabled for cache.
+     */
+    public boolean mvccEnabled() {
+        return cacheCfg.isMvccEnabled();
+    }
+
+    /**
      * @param part Partition.
      * @param affNodes Affinity nodes.
      * @param topVer Topology version.

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheProcessor.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheProcessor.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheProcessor.java
index bd950fa..030f7e7 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheProcessor.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheProcessor.java
@@ -86,6 +86,7 @@ import org.apache.ignite.internal.processors.cache.dr.GridCacheDrManager;
 import org.apache.ignite.internal.processors.cache.jta.CacheJtaManagerAdapter;
 import org.apache.ignite.internal.processors.cache.local.GridLocalCache;
 import org.apache.ignite.internal.processors.cache.local.atomic.GridLocalAtomicCache;
+import org.apache.ignite.internal.processors.cache.mvcc.CacheCoordinatorsSharedManager;
 import org.apache.ignite.internal.processors.cache.persistence.GridCacheDatabaseSharedManager;
 import org.apache.ignite.internal.processors.cache.persistence.IgniteCacheDatabaseSharedManager;
 import org.apache.ignite.internal.processors.cache.persistence.MemoryPolicy;
@@ -456,10 +457,16 @@ public class GridCacheProcessor extends GridProcessorAdapter {
 
         ctx.igfsHelper().validateCacheConfiguration(cc);
 
-        if (cc.getAtomicityMode() == ATOMIC)
+        if (cc.getAtomicityMode() == ATOMIC) {
             assertParameter(cc.getTransactionManagerLookupClassName() == null,
                 "transaction manager can not be used with ATOMIC cache");
 
+            assertParameter(!cc.isMvccEnabled(), "MVCC can not used with ATOMIC cache");
+        }
+
+        if (cc.getCacheMode() == LOCAL)
+            assertParameter(!cc.isMvccEnabled(), "MVCC can not used with LOCAL cache");
+
         if (cc.getEvictionPolicy() != null && !cc.isOnheapCacheEnabled())
             throw new IgniteCheckedException("Onheap cache must be enabled if eviction policy is configured [cacheName="
                 + U.maskName(cc.getName()) + "]");
@@ -2170,6 +2177,7 @@ public class GridCacheProcessor extends GridProcessorAdapter {
     @SuppressWarnings("unchecked")
     private GridCacheSharedContext createSharedContext(GridKernalContext kernalCtx,
         Collection<CacheStoreSessionListener> storeSesLsnrs) throws IgniteCheckedException {
+        CacheCoordinatorsSharedManager coord = new CacheCoordinatorsSharedManager();
         IgniteTxManager tm = new IgniteTxManager();
         GridCacheMvccManager mvccMgr = new GridCacheMvccManager();
         GridCacheVersionManager verMgr = new GridCacheVersionManager();
@@ -2208,6 +2216,7 @@ public class GridCacheProcessor extends GridProcessorAdapter {
 
         return new GridCacheSharedContext(
             kernalCtx,
+            coord,
             tm,
             verMgr,
             mvccMgr,

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheSharedContext.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheSharedContext.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheSharedContext.java
index 82d960a..09c8b1a 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheSharedContext.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/GridCacheSharedContext.java
@@ -46,6 +46,7 @@ import org.apache.ignite.internal.processors.cache.distributed.dht.GridDhtPartit
 import org.apache.ignite.internal.processors.cache.distributed.dht.GridDhtTopologyFuture;
 import org.apache.ignite.internal.processors.cache.distributed.near.GridNearTxLocal;
 import org.apache.ignite.internal.processors.cache.jta.CacheJtaManagerAdapter;
+import org.apache.ignite.internal.processors.cache.mvcc.CacheCoordinatorsSharedManager;
 import org.apache.ignite.internal.processors.cache.persistence.IgniteCacheDatabaseSharedManager;
 import org.apache.ignite.internal.processors.cache.persistence.snapshot.IgniteCacheSnapshotManager;
 import org.apache.ignite.internal.processors.cache.store.CacheStoreManager;
@@ -122,6 +123,9 @@ public class GridCacheSharedContext<K, V> {
     /** Ttl cleanup manager. */
     private GridCacheSharedTtlCleanupManager ttlMgr;
 
+    /** Cache mvcc coordinator. */
+    private CacheCoordinatorsSharedManager coord;
+
     /** Cache contexts map. */
     private ConcurrentHashMap8<Integer, GridCacheContext<K, V>> ctxMap;
 
@@ -163,6 +167,7 @@ public class GridCacheSharedContext<K, V> {
 
     /**
      * @param kernalCtx  Context.
+     * @param coord Cache mvcc coordinator manager.
      * @param txMgr Transaction manager.
      * @param verMgr Version manager.
      * @param mvccMgr MVCC manager.
@@ -176,6 +181,7 @@ public class GridCacheSharedContext<K, V> {
      */
     public GridCacheSharedContext(
         GridKernalContext kernalCtx,
+        CacheCoordinatorsSharedManager coord,
         IgniteTxManager txMgr,
         GridCacheVersionManager verMgr,
         GridCacheMvccManager mvccMgr,
@@ -193,7 +199,21 @@ public class GridCacheSharedContext<K, V> {
     ) {
         this.kernalCtx = kernalCtx;
 
-        setManagers(mgrs, txMgr, jtaMgr, verMgr, mvccMgr, pageStoreMgr, walMgr, dbMgr, snpMgr, depMgr, exchMgr, affMgr, ioMgr, ttlMgr);
+        setManagers(mgrs,
+            coord,
+            txMgr,
+            jtaMgr,
+            verMgr,
+            mvccMgr,
+            pageStoreMgr,
+            walMgr,
+            dbMgr,
+            snpMgr,
+            depMgr,
+            exchMgr,
+            affMgr,
+            ioMgr,
+            ttlMgr);
 
         this.storeSesLsnrs = storeSesLsnrs;
 
@@ -335,7 +355,9 @@ public class GridCacheSharedContext<K, V> {
     void onReconnected(boolean active) throws IgniteCheckedException {
         List<GridCacheSharedManager<K, V>> mgrs = new LinkedList<>();
 
-        setManagers(mgrs, txMgr,
+        setManagers(mgrs,
+            coord,
+            txMgr,
             jtaMgr,
             verMgr,
             mvccMgr,
@@ -374,6 +396,7 @@ public class GridCacheSharedContext<K, V> {
 
     /**
      * @param mgrs Managers list.
+     * @param coord Cache mvcc coordinator manager.
      * @param txMgr Transaction manager.
      * @param jtaMgr JTA manager.
      * @param verMgr Version manager.
@@ -385,6 +408,7 @@ public class GridCacheSharedContext<K, V> {
      * @param ttlMgr Ttl cleanup manager.
      */
     private void setManagers(List<GridCacheSharedManager<K, V>> mgrs,
+        CacheCoordinatorsSharedManager coord,
         IgniteTxManager txMgr,
         CacheJtaManagerAdapter jtaMgr,
         GridCacheVersionManager verMgr,
@@ -398,6 +422,7 @@ public class GridCacheSharedContext<K, V> {
         CacheAffinitySharedManager affMgr,
         GridCacheIoManager ioMgr,
         GridCacheSharedTtlCleanupManager ttlMgr) {
+        this.coord = add(mgrs, coord);
         this.mvccMgr = add(mgrs, mvccMgr);
         this.verMgr = add(mgrs, verMgr);
         this.txMgr = add(mgrs, txMgr);
@@ -738,6 +763,13 @@ public class GridCacheSharedContext<K, V> {
     }
 
     /**
+     * @return Cache mvcc coordinator manager.
+     */
+    public CacheCoordinatorsSharedManager coordinators() {
+        return coord;
+    }
+
+    /**
      * @return Node ID.
      */
     public UUID localNodeId() {

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/CacheCoordinatorsSharedManager.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/CacheCoordinatorsSharedManager.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/CacheCoordinatorsSharedManager.java
new file mode 100644
index 0000000..e5d07ea
--- /dev/null
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/CacheCoordinatorsSharedManager.java
@@ -0,0 +1,454 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.ignite.internal.processors.cache.mvcc;
+
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.atomic.AtomicLong;
+import org.apache.ignite.IgniteCheckedException;
+import org.apache.ignite.cluster.ClusterNode;
+import org.apache.ignite.events.DiscoveryEvent;
+import org.apache.ignite.events.Event;
+import org.apache.ignite.internal.IgniteInternalFuture;
+import org.apache.ignite.internal.cluster.ClusterTopologyCheckedException;
+import org.apache.ignite.internal.managers.communication.GridMessageListener;
+import org.apache.ignite.internal.managers.discovery.DiscoCache;
+import org.apache.ignite.internal.managers.eventstorage.GridLocalEventListener;
+import org.apache.ignite.internal.processors.cache.GridCacheSharedManagerAdapter;
+import org.apache.ignite.internal.processors.cache.version.GridCacheVersion;
+import org.apache.ignite.internal.util.future.GridFutureAdapter;
+import org.apache.ignite.internal.util.typedef.internal.U;
+import org.jetbrains.annotations.Nullable;
+
+import static org.apache.ignite.events.EventType.EVT_NODE_FAILED;
+import static org.apache.ignite.events.EventType.EVT_NODE_LEFT;
+import static org.apache.ignite.internal.GridTopic.TOPIC_CACHE_COORDINATOR;
+import static org.apache.ignite.internal.managers.communication.GridIoPolicy.SYSTEM_POOL;
+
+/**
+ *
+ */
+public class CacheCoordinatorsSharedManager<K, V> extends GridCacheSharedManagerAdapter<K, V> {
+    /** */
+    private final AtomicLong mvccCntr = new AtomicLong(0L);
+
+    /** */
+    private final AtomicLong committedCntr = new AtomicLong(0L);
+
+    /** */
+    private final ConcurrentHashMap<GridCacheVersion, Long> activeTxs = new ConcurrentHashMap<>();
+
+    /** */
+    private final ConcurrentMap<Long, MvccCounterFuture> cntrFuts = new ConcurrentHashMap<>();
+
+    /** */
+    private final ConcurrentMap<Long, TxAckFuture> ackFuts = new ConcurrentHashMap<>();
+
+    /** */
+    private final AtomicLong futIdCntr = new AtomicLong();
+
+    /** {@inheritDoc} */
+    @Override protected void start0() throws IgniteCheckedException {
+        super.start0();
+
+        cctx.gridEvents().addLocalEventListener(new CacheCoordinatorDiscoveryListener(),
+            EVT_NODE_FAILED, EVT_NODE_LEFT);
+
+        cctx.gridIO().addMessageListener(TOPIC_CACHE_COORDINATOR, new CoordinatorMessageListener());
+    }
+
+    /**
+     * @param crd Coordinator.
+     * @param txId Transaction ID.
+     * @return Counter request future.
+     */
+    public IgniteInternalFuture<Long> requestTxCounter(ClusterNode crd, GridCacheVersion txId) {
+        MvccCounterFuture fut = new MvccCounterFuture(futIdCntr.incrementAndGet(), crd);
+
+        cntrFuts.put(fut.id, fut);
+
+        try {
+            cctx.gridIO().sendToGridTopic(crd,
+                TOPIC_CACHE_COORDINATOR,
+                new CoordinatorTxCounterRequest(fut.id, txId),
+                SYSTEM_POOL);
+        }
+        catch (IgniteCheckedException e) {
+            if (cntrFuts.remove(fut.id) != null)
+                fut.onDone(e);
+        }
+
+        return fut;
+    }
+
+    public IgniteInternalFuture<Long> requestQueryCounter(ClusterNode crd) {
+        MvccCounterFuture fut = new MvccCounterFuture(futIdCntr.incrementAndGet(), crd);
+
+        cntrFuts.put(fut.id, fut);
+
+        try {
+            cctx.gridIO().sendToGridTopic(crd,
+                TOPIC_CACHE_COORDINATOR,
+                new CoordinatorQueryCounterRequest(fut.id),
+                SYSTEM_POOL);
+        }
+        catch (IgniteCheckedException e) {
+            if (cntrFuts.remove(fut.id) != null)
+                fut.onDone(e);
+        }
+
+        return fut;
+    }
+
+    /**
+     * @param txId Transaction ID.
+     * @return Acknowledge future.
+     */
+    public IgniteInternalFuture<Void> ackTxCommit(ClusterNode crd, GridCacheVersion txId) {
+        TxAckFuture fut = new TxAckFuture(futIdCntr.incrementAndGet(), crd);
+
+        ackFuts.put(fut.id, fut);
+
+        try {
+            cctx.gridIO().sendToGridTopic(crd,
+                TOPIC_CACHE_COORDINATOR,
+                new CoordinatorTxAckRequest(fut.id, txId),
+                SYSTEM_POOL);
+        }
+        catch (ClusterTopologyCheckedException e) {
+            if (cntrFuts.remove(fut.id) != null)
+                fut.onDone();
+        }
+        catch (IgniteCheckedException e) {
+            if (cntrFuts.remove(fut.id) != null)
+                fut.onDone(e);
+        }
+
+        return fut;
+    }
+
+    public void ackTxRollback(ClusterNode crd, GridCacheVersion txId) {
+        CoordinatorTxAckRequest msg = new CoordinatorTxAckRequest(0, txId);
+
+        msg.skipResponse(true);
+
+        try {
+            cctx.gridIO().sendToGridTopic(crd,
+                TOPIC_CACHE_COORDINATOR,
+                msg,
+                SYSTEM_POOL);
+        }
+        catch (ClusterTopologyCheckedException e) {
+            if (log.isDebugEnabled())
+                log.debug("Failed to send tx rollback ack, node left [msg=" + msg + ", node=" + crd.id() + ']');
+        }
+        catch (IgniteCheckedException e) {
+            U.error(log, "Failed to send tx rollback ack [msg=" + msg + ", node=" + crd.id() + ']', e);
+        }
+    }
+
+
+    /**
+     * @param txId Transaction ID.
+     * @return Counter.
+     */
+    private long assignTxCounter(GridCacheVersion txId) {
+        long nextCtr = mvccCntr.incrementAndGet();
+
+        Object old = activeTxs.put(txId, nextCtr);
+
+        assert old == null : txId;
+
+        return nextCtr;
+    }
+
+    /**
+     * @param nodeId Sender node ID.
+     * @param msg Message.
+     */
+    private void processCoordinatorTxCounterRequest(UUID nodeId, CoordinatorTxCounterRequest msg) {
+        ClusterNode node = cctx.discovery().node(nodeId);
+
+        if (node == null) {
+            if (log.isDebugEnabled())
+                log.debug("Ignore tx counter request processing, node left [msg=" + msg + ", node=" + nodeId + ']');
+
+            return;
+        }
+
+        long nextCtr = assignTxCounter(msg.txId());
+
+        try {
+            cctx.gridIO().sendToGridTopic(node,
+                TOPIC_CACHE_COORDINATOR,
+                new CoordinatorMvccCounterResponse(nextCtr, msg.futureId()),
+                SYSTEM_POOL);
+        }
+        catch (ClusterTopologyCheckedException e) {
+            if (log.isDebugEnabled())
+                log.debug("Failed to send tx counter response, node left [msg=" + msg + ", node=" + nodeId + ']');
+        }
+        catch (IgniteCheckedException e) {
+            U.error(log, "Failed to send tx counter response [msg=" + msg + ", node=" + nodeId + ']', e);
+        }
+    }
+
+    /**
+     * @param nodeId Sender node ID.
+     * @param msg Message.
+     */
+    private void processCoordinatorCounterResponse(UUID nodeId, CoordinatorMvccCounterResponse msg) {
+        MvccCounterFuture fut = cntrFuts.remove(msg.futureId());
+
+        if (fut != null)
+            fut.onResponse(msg.counter());
+        else {
+            if (cctx.discovery().alive(nodeId))
+                U.warn(log, "Failed to find coordinator counter future [node=" + nodeId + ", msg=" + msg + ']');
+            else if (log.isDebugEnabled())
+                log.debug("Failed to find query counter future [node=" + nodeId + ", msg=" + msg + ']');
+        }
+    }
+    /**
+     *
+     * @param nodeId Sender node ID.
+     * @param msg Message.
+     */
+    private void processCoordinatorQueryStateRequest(UUID nodeId, CoordinatorQueryCounterRequest msg) {
+        ClusterNode node = cctx.discovery().node(nodeId);
+
+        if (node == null) {
+            if (log.isDebugEnabled())
+                log.debug("Ignore query counter request processing, node left [msg=" + msg + ", node=" + nodeId + ']');
+
+            return;
+        }
+
+        long qryCntr = assignQueryCounter(nodeId);
+
+        CoordinatorMvccCounterResponse res = new CoordinatorMvccCounterResponse(msg.futureId(), qryCntr);
+
+        try {
+            cctx.gridIO().sendToGridTopic(node,
+                TOPIC_CACHE_COORDINATOR,
+                res,
+                SYSTEM_POOL);
+        }
+        catch (ClusterTopologyCheckedException e) {
+            if (log.isDebugEnabled())
+                log.debug("Failed to send query counter response, node left [msg=" + msg + ", node=" + nodeId + ']');
+
+            onQueryDone(qryCntr);
+        }
+        catch (IgniteCheckedException e) {
+            U.error(log, "Failed to send query counter response [msg=" + msg + ", node=" + nodeId + ']', e);
+
+            onQueryDone(qryCntr);
+        }
+    }
+
+    /**
+     * @param msg Message.
+     */
+    private void processCoordinatorQueryAckRequest(CoordinatorQueryAckRequest msg) {
+        onQueryDone(msg.counter());
+    }
+
+    /**
+     * @param nodeId Sender node ID.
+     * @param msg Message.
+     */
+    private void processCoordinatorTxAckRequest(UUID nodeId, CoordinatorTxAckRequest msg) {
+        activeTxs.remove(msg.txId());
+
+        if (!msg.skipResponse()) {
+            try {
+                cctx.gridIO().sendToGridTopic(nodeId,
+                    TOPIC_CACHE_COORDINATOR,
+                    new CoordinatorTxAckResponse(msg.futureId()),
+                    SYSTEM_POOL);
+            }
+            catch (ClusterTopologyCheckedException e) {
+                if (log.isDebugEnabled())
+                    log.debug("Failed to send tx ack response, node left [msg=" + msg + ", node=" + nodeId + ']');
+            }
+            catch (IgniteCheckedException e) {
+                U.error(log, "Failed to send tx ack response [msg=" + msg + ", node=" + nodeId + ']', e);
+            }
+        }
+    }
+
+    /**
+     * @param nodeId Sender node ID.
+     * @param msg Message.
+     */
+    private void processCoordinatorTxAckResponse(UUID nodeId, CoordinatorTxAckResponse msg) {
+        TxAckFuture fut = ackFuts.get(msg.futureId());
+
+        if (fut != null)
+            fut.onResponse();
+        else {
+            if (cctx.discovery().alive(nodeId))
+                U.warn(log, "Failed to find tx ack future [node=" + nodeId + ", msg=" + msg + ']');
+            else if (log.isDebugEnabled())
+                log.debug("Failed to find tx ack future [node=" + nodeId + ", msg=" + msg + ']');
+        }
+    }
+
+    /**
+     * @param qryNodeId Node initiated query.
+     * @return Counter for query.
+     */
+    private long assignQueryCounter(UUID qryNodeId) {
+        // TODO IGNITE-3478
+        return committedCntr.get();
+    }
+
+    /**
+     * @param cntr Query counter.
+     */
+    private void onQueryDone(long cntr) {
+        // TODO IGNITE-3478
+    }
+
+    /**
+     * @param discoCache Cluster topology.
+     * @return Assigned coordinator.
+     */
+    @Nullable public ClusterNode assignCoordinator(DiscoCache discoCache) {
+        // TODO IGNITE-3478
+        List<ClusterNode> srvNodes = discoCache.serverNodes();
+
+        return srvNodes.isEmpty() ? null : srvNodes.get(0);
+    }
+
+    /**
+     *
+     */
+    private class MvccCounterFuture extends GridFutureAdapter<Long> {
+        /** */
+        private final Long id;
+
+        /** */
+        private final ClusterNode crd;
+
+        /**
+         * @param id Future ID.
+         * @param crd Coordinator.
+         */
+        MvccCounterFuture(Long id, ClusterNode crd) {
+            this.id = id;
+            this.crd = crd;
+        }
+
+        /**
+         * @param cntr Counter.
+         */
+        void onResponse(long cntr) {
+            onDone(cntr);
+        }
+
+        /**
+         * @param nodeId Failed node ID.
+         */
+        void onNodeLeft(UUID nodeId) {
+            if (crd.id().equals(nodeId) && cntrFuts.remove(id) != null)
+                onDone(new ClusterTopologyCheckedException("Failed to request counter, node failed: " + nodeId));
+        }
+    }
+
+    /**
+     *
+     */
+    private class TxAckFuture extends GridFutureAdapter<Void> {
+        /** */
+        private final Long id;
+
+        /** */
+        private final ClusterNode crd;
+
+        /**
+         * @param id Future ID.
+         * @param crd Coordinator.
+         */
+        TxAckFuture(Long id, ClusterNode crd) {
+            this.id = id;
+            this.crd = crd;
+        }
+
+        /**
+         *
+         */
+        void onResponse() {
+            onDone();
+        }
+
+        /**
+         * @param nodeId Failed node ID.
+         */
+        void onNodeLeft(UUID nodeId) {
+            if (crd.id().equals(nodeId) && cntrFuts.remove(id) != null)
+                onDone();
+        }
+    }
+
+    /**
+     *
+     */
+    private class CacheCoordinatorDiscoveryListener implements GridLocalEventListener {
+        /** {@inheritDoc} */
+        @Override public void onEvent(Event evt) {
+            assert evt instanceof DiscoveryEvent : evt;
+
+            DiscoveryEvent discoEvt = (DiscoveryEvent)evt;
+
+            UUID nodeId = discoEvt.eventNode().id();
+
+            for (MvccCounterFuture fut : cntrFuts.values())
+                fut.onNodeLeft(nodeId);
+
+//            for (AckFuture fut : ackFuts.values())
+//                fut.onNodeLeft(nodeId);
+//
+        }
+    }
+    /**
+     *
+     */
+    private class CoordinatorMessageListener implements GridMessageListener {
+        /** {@inheritDoc} */
+        @Override public void onMessage(UUID nodeId, Object msg, byte plc) {
+            if (msg instanceof CoordinatorTxCounterRequest)
+                processCoordinatorTxCounterRequest(nodeId, (CoordinatorTxCounterRequest)msg);
+            else if (msg instanceof CoordinatorMvccCounterResponse)
+                processCoordinatorCounterResponse(nodeId, (CoordinatorMvccCounterResponse)msg);
+            else if (msg instanceof CoordinatorTxAckRequest)
+                processCoordinatorTxAckRequest(nodeId, (CoordinatorTxAckRequest)msg);
+            else if (msg instanceof CoordinatorTxAckResponse)
+                processCoordinatorTxAckResponse(nodeId, (CoordinatorTxAckResponse)msg);
+            else if (msg instanceof CoordinatorQueryAckRequest)
+                processCoordinatorQueryAckRequest((CoordinatorQueryAckRequest)msg);
+            else if (msg instanceof CoordinatorQueryCounterRequest)
+                processCoordinatorQueryStateRequest(nodeId, (CoordinatorQueryCounterRequest)msg);
+            else
+                U.warn(log, "Unexpected message received: " + msg);
+        }
+    }
+}

http://git-wip-us.apache.org/repos/asf/ignite/blob/f6e98254/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/CoordinatorMvccCounterResponse.java
----------------------------------------------------------------------
diff --git a/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/CoordinatorMvccCounterResponse.java b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/CoordinatorMvccCounterResponse.java
new file mode 100644
index 0000000..5005477
--- /dev/null
+++ b/modules/core/src/main/java/org/apache/ignite/internal/processors/cache/mvcc/CoordinatorMvccCounterResponse.java
@@ -0,0 +1,147 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.ignite.internal.processors.cache.mvcc;
+
+import java.nio.ByteBuffer;
+import org.apache.ignite.internal.managers.communication.GridIoMessageFactory;
+import org.apache.ignite.internal.util.typedef.internal.S;
+import org.apache.ignite.plugin.extensions.communication.Message;
+import org.apache.ignite.plugin.extensions.communication.MessageReader;
+import org.apache.ignite.plugin.extensions.communication.MessageWriter;
+
+/**
+ *
+ */
+public class CoordinatorMvccCounterResponse implements Message {
+    /** */
+    private static final long serialVersionUID = 0L;
+
+    /** */
+    private long cntr;
+
+    /** */
+    private long futId;
+
+    /**
+     * Required by {@link GridIoMessageFactory}.
+     */
+    public CoordinatorMvccCounterResponse() {
+        // No-op.
+    }
+
+    /**
+     * @param cntr Counter.
+     * @param futId Future ID.
+     */
+    CoordinatorMvccCounterResponse(long cntr, long futId) {
+        this.cntr = cntr;
+        this.futId = futId;
+    }
+
+    /**
+     * @return Future ID.
+     */
+    public long futureId() {
+        return futId;
+    }
+
+    /**
+     * @return Counter.
+     */
+    public long counter() {
+        return cntr;
+    }
+
+    /** {@inheritDoc} */
+    @Override public boolean writeTo(ByteBuffer buf, MessageWriter writer) {
+        writer.setBuffer(buf);
+
+        if (!writer.isHeaderWritten()) {
+            if (!writer.writeHeader(directType(), fieldsCount()))
+                return false;
+
+            writer.onHeaderWritten();
+        }
+
+        switch (writer.state()) {
+            case 0:
+                if (!writer.writeLong("cntr", cntr))
+                    return false;
+
+                writer.incrementState();
+
+            case 1:
+                if (!writer.writeLong("futId", futId))
+                    return false;
+
+                writer.incrementState();
+
+        }
+
+        return true;
+    }
+
+    /** {@inheritDoc} */
+    @Override public boolean readFrom(ByteBuffer buf, MessageReader reader) {
+        reader.setBuffer(buf);
+
+        if (!reader.beforeMessageRead())
+            return false;
+
+        switch (reader.state()) {
+            case 0:
+                cntr = reader.readLong("cntr");
+
+                if (!reader.isLastRead())
+                    return false;
+
+                reader.incrementState();
+
+            case 1:
+                futId = reader.readLong("futId");
+
+                if (!reader.isLastRead())
+                    return false;
+
+                reader.incrementState();
+
+        }
+
+        return reader.afterMessageRead(CoordinatorMvccCounterResponse.class);
+    }
+
+    /** {@inheritDoc} */
+    @Override public short directType() {
+        return 130;
+    }
+
+    /** {@inheritDoc} */
+    @Override public byte fieldsCount() {
+        return 2;
+    }
+
+    /** {@inheritDoc} */
+    @Override public void onAckReceived() {
+        // No-op.
+    }
+
+    /** {@inheritDoc} */
+    @Override public String toString() {
+        return S.toString(CoordinatorMvccCounterResponse.class, this);
+    }
+}