diff --git a/pom.xml b/pom.xml
index dd34f060b3f..1ba5ddf30cb 100644
--- a/pom.xml
+++ b/pom.xml
@@ -265,6 +265,18 @@
             <artifactId>simpleclient_pushgateway</artifactId>
             <version>0.10.0</version>
         </dependency>
+        <dependency>
+            <groupId>org.powermock</groupId>
+            <artifactId>powermock-module-junit4</artifactId>
+            <version>2.0.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.powermock</groupId>
+            <artifactId>powermock-api-mockito2</artifactId>
+            <version>2.0.2</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <reporting>
         <plugins>
diff --git a/src/main/java/org/tikv/common/exception/KeyException.java b/src/main/java/org/tikv/common/exception/KeyException.java
index 22ddda982b9..048ac3b35fe 100644
--- a/src/main/java/org/tikv/common/exception/KeyException.java
+++ b/src/main/java/org/tikv/common/exception/KeyException.java
@@ -31,7 +31,7 @@ public KeyException(String errMsg) {
   }
 
   public KeyException(Kvrpcpb.KeyError keyErr) {
-    super("Key exception occurred");
+    super("Key exception occurred " + keyErr.toString());
     this.keyErr = keyErr;
   }
 
diff --git a/src/main/java/org/tikv/common/region/RegionStoreClient.java b/src/main/java/org/tikv/common/region/RegionStoreClient.java
index 22607b2bdb1..3228650c0ff 100644
--- a/src/main/java/org/tikv/common/region/RegionStoreClient.java
+++ b/src/main/java/org/tikv/common/region/RegionStoreClient.java
@@ -519,7 +519,7 @@ private boolean isPrewriteSuccess(BackOffer backOffer, PrewriteResponse resp, lo
         Lock lock = new Lock(err.getLocked(), codec);
         locks.add(lock);
       } else {
-        throw new KeyException(err.toString());
+        throw new KeyException(err);
       }
     }
     if (isSuccess) {
diff --git a/src/main/java/org/tikv/txn/TxnKVClient.java b/src/main/java/org/tikv/txn/TxnKVClient.java
index 7806c56496e..9c5f4c9da3a 100644
--- a/src/main/java/org/tikv/txn/TxnKVClient.java
+++ b/src/main/java/org/tikv/txn/TxnKVClient.java
@@ -27,7 +27,6 @@
 import org.tikv.common.ReadOnlyPDClient;
 import org.tikv.common.TiConfiguration;
 import org.tikv.common.exception.GrpcException;
-import org.tikv.common.exception.KeyException;
 import org.tikv.common.exception.RegionException;
 import org.tikv.common.exception.TiClientInternalException;
 import org.tikv.common.exception.TiKVException;
@@ -181,7 +180,6 @@ public ClientRPCResult commit(
   // TODO: check this logic to see are we satisfied?
   private boolean retryableException(Exception e) {
     return e instanceof TiClientInternalException
-        || e instanceof KeyException
         || e instanceof RegionException
         || e instanceof StatusRuntimeException;
   }
diff --git a/src/test/java/org/tikv/txn/TwoPhaseCommitterTest.java b/src/test/java/org/tikv/txn/TwoPhaseCommitterTest.java
index 02a530ffbc6..ecb150b5673 100644
--- a/src/test/java/org/tikv/txn/TwoPhaseCommitterTest.java
+++ b/src/test/java/org/tikv/txn/TwoPhaseCommitterTest.java
@@ -20,17 +20,40 @@
 import static org.junit.Assert.fail;
 
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicLong;
+import org.apache.commons.lang3.RandomStringUtils;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mockito;
+import org.powermock.api.mockito.PowerMockito;
+import org.powermock.core.classloader.annotations.PowerMockIgnore;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.tikv.BaseTxnKVTest;
+import org.tikv.common.BytePairWrapper;
 import org.tikv.common.TiConfiguration;
 import org.tikv.common.TiSession;
+import org.tikv.common.exception.KeyException;
+import org.tikv.common.util.BackOffer;
+import org.tikv.common.util.ConcreteBackOffer;
 
+@RunWith(PowerMockRunner.class)
+@PrepareForTest({TiSession.class, TxnKVClient.class, TwoPhaseCommitter.class})
+@PowerMockIgnore({"javax.net.ssl.*"})
 public class TwoPhaseCommitterTest extends BaseTxnKVTest {
+
+  private static final Logger logger = LoggerFactory.getLogger(TwoPhaseCommitterTest.class);
   private static final int WRITE_BUFFER_SIZE = 32 * 1024;
   private static final int TXN_COMMIT_BATCH_SIZE = 768 * 1024;
   private static final long DEFAULT_BATCH_WRITE_LOCK_TTL = 3600000;
@@ -76,4 +99,170 @@ public void autoClosableTest() throws Exception {
             executorService)) {}
     Assert.assertTrue(executorService.isShutdown());
   }
+
+  @Test
+  public void prewriteWriteConflictFastFailTest() throws Exception {
+
+    int WRITE_BUFFER_SIZE = 32;
+    String primaryKey = RandomStringUtils.randomAlphabetic(3);
+    AtomicLong failCount = new AtomicLong();
+    ExecutorService executorService =
+        Executors.newFixedThreadPool(
+            WRITE_BUFFER_SIZE,
+            new ThreadFactoryBuilder().setNameFormat("2pc-pool-%d").setDaemon(true).build());
+    CountDownLatch latch = new CountDownLatch(2);
+    int DEFAULT_BATCH_WRITE_LOCK_TTL = 10000;
+    new Thread(
+            () -> {
+              long startTS = session.getTimestamp().getVersion();
+              try {
+                Thread.sleep(1000);
+              } catch (InterruptedException e) {
+                throw new RuntimeException(e);
+              }
+              try {
+                TwoPhaseCommitter twoPhaseCommitter =
+                    new TwoPhaseCommitter(
+                        session, startTS, DEFAULT_BATCH_WRITE_LOCK_TTL, executorService);
+                List<BytePairWrapper> pairs =
+                    Arrays.asList(
+                        new BytePairWrapper(
+                            primaryKey.getBytes(StandardCharsets.UTF_8),
+                            primaryKey.getBytes(StandardCharsets.UTF_8)));
+                twoPhaseCommitter.prewriteSecondaryKeys(
+                    primaryKey.getBytes(StandardCharsets.UTF_8), pairs.iterator(), 20000);
+                BackOffer backOffer = ConcreteBackOffer.newCustomBackOff(20000);
+
+                long commitTs = session.getTimestamp().getVersion();
+
+                twoPhaseCommitter.commitPrimaryKey(
+                    backOffer, primaryKey.getBytes(StandardCharsets.UTF_8), commitTs);
+              } catch (Exception e) {
+                logger.error(e.getMessage(), e);
+                failCount.incrementAndGet();
+              } finally {
+                latch.countDown();
+              }
+            })
+        .start();
+
+    Thread.sleep(10);
+    new Thread(
+            () -> {
+              long startTS = session.getTimestamp().getVersion();
+              try {
+                TwoPhaseCommitter twoPhaseCommitter =
+                    new TwoPhaseCommitter(
+                        session, startTS, DEFAULT_BATCH_WRITE_LOCK_TTL, executorService);
+                List<BytePairWrapper> pairs =
+                    Arrays.asList(
+                        new BytePairWrapper(
+                            primaryKey.getBytes(StandardCharsets.UTF_8),
+                            primaryKey.getBytes(StandardCharsets.UTF_8)));
+                twoPhaseCommitter.prewriteSecondaryKeys(
+                    primaryKey.getBytes(StandardCharsets.UTF_8), pairs.iterator(), 20000);
+                BackOffer backOffer = ConcreteBackOffer.newCustomBackOff(20000);
+
+                long commitTs = session.getTimestamp().getVersion();
+
+                twoPhaseCommitter.commitPrimaryKey(
+                    backOffer, primaryKey.getBytes(StandardCharsets.UTF_8), commitTs);
+              } catch (Exception e) {
+                logger.error(e.getMessage(), e);
+                failCount.incrementAndGet();
+              } finally {
+                latch.countDown();
+              }
+            })
+        .start();
+    latch.await();
+    Assert.assertEquals(1, failCount.get());
+  }
+
+  @Test
+  public void prewriteWriteConflictLongNoFailTest() throws Exception {
+
+    int WRITE_BUFFER_SIZE = 32;
+    String primaryKey = RandomStringUtils.randomAlphabetic(3);
+    AtomicLong failCount = new AtomicLong();
+    ExecutorService executorService =
+        Executors.newFixedThreadPool(
+            WRITE_BUFFER_SIZE,
+            new ThreadFactoryBuilder().setNameFormat("2pc-pool-%d").setDaemon(true).build());
+    CountDownLatch latch = new CountDownLatch(2);
+    int DEFAULT_BATCH_WRITE_LOCK_TTL = 10000;
+
+    new Thread(
+            () -> {
+              long startTS = session.getTimestamp().getVersion();
+              try {
+                Thread.sleep(1000);
+              } catch (InterruptedException e) {
+                throw new RuntimeException(e);
+              }
+
+              try {
+                session = PowerMockito.spy(session);
+                TxnKVClient kvClient = PowerMockito.spy(session.createTxnClient());
+                PowerMockito.when(kvClient, "retryableException", Mockito.any(KeyException.class))
+                    .thenReturn(true);
+                PowerMockito.doReturn(kvClient).when(session).createTxnClient();
+
+                TwoPhaseCommitter twoPhaseCommitter =
+                    new TwoPhaseCommitter(
+                        session, startTS, DEFAULT_BATCH_WRITE_LOCK_TTL, executorService);
+                List<BytePairWrapper> pairs =
+                    Arrays.asList(
+                        new BytePairWrapper(
+                            primaryKey.getBytes(StandardCharsets.UTF_8),
+                            primaryKey.getBytes(StandardCharsets.UTF_8)));
+                twoPhaseCommitter.prewriteSecondaryKeys(
+                    primaryKey.getBytes(StandardCharsets.UTF_8), pairs.iterator(), 20000);
+                BackOffer backOffer = ConcreteBackOffer.newCustomBackOff(20000);
+
+                long commitTs = session.getTimestamp().getVersion();
+
+                twoPhaseCommitter.commitPrimaryKey(
+                    backOffer, primaryKey.getBytes(StandardCharsets.UTF_8), commitTs);
+              } catch (Exception e) {
+                logger.error(e.getMessage(), e);
+                failCount.incrementAndGet();
+              } finally {
+                latch.countDown();
+              }
+            })
+        .start();
+
+    Thread.sleep(10);
+    new Thread(
+            () -> {
+              long startTS = session.getTimestamp().getVersion();
+              try {
+                TwoPhaseCommitter twoPhaseCommitter =
+                    new TwoPhaseCommitter(
+                        session, startTS, DEFAULT_BATCH_WRITE_LOCK_TTL, executorService);
+                List<BytePairWrapper> pairs =
+                    Arrays.asList(
+                        new BytePairWrapper(
+                            primaryKey.getBytes(StandardCharsets.UTF_8),
+                            primaryKey.getBytes(StandardCharsets.UTF_8)));
+                twoPhaseCommitter.prewriteSecondaryKeys(
+                    primaryKey.getBytes(StandardCharsets.UTF_8), pairs.iterator(), 20000);
+                BackOffer backOffer = ConcreteBackOffer.newCustomBackOff(20000);
+
+                long commitTs = session.getTimestamp().getVersion();
+
+                twoPhaseCommitter.commitPrimaryKey(
+                    backOffer, primaryKey.getBytes(StandardCharsets.UTF_8), commitTs);
+              } catch (Exception e) {
+                logger.error(e.getMessage(), e);
+                failCount.incrementAndGet();
+              } finally {
+                latch.countDown();
+              }
+            })
+        .start();
+    latch.await();
+    Assert.assertEquals(1, failCount.get());
+  }
 }