diff --git a/src/main/java/org/tikv/common/AbstractGRPCClient.java b/src/main/java/org/tikv/common/AbstractGRPCClient.java
index d2675f94385..ac68552f7e2 100644
--- a/src/main/java/org/tikv/common/AbstractGRPCClient.java
+++ b/src/main/java/org/tikv/common/AbstractGRPCClient.java
@@ -182,6 +182,8 @@ public long getTimeout() {
 
   private boolean doCheckHealth(BackOffer backOffer, String addressStr, HostMapping hostMapping) {
     while (true) {
+      backOffer.checkTimeout();
+
       try {
         ManagedChannel channel = channelFactory.getChannel(addressStr, hostMapping);
         HealthGrpc.HealthBlockingStub stub =
@@ -198,10 +200,6 @@ private boolean doCheckHealth(BackOffer backOffer, String addressStr, HostMappin
   }
 
   protected boolean checkHealth(BackOffer backOffer, String addressStr, HostMapping hostMapping) {
-    try {
-      return doCheckHealth(backOffer, addressStr, hostMapping);
-    } catch (Exception e) {
-      return false;
-    }
+    return doCheckHealth(backOffer, addressStr, hostMapping);
   }
 }
diff --git a/src/main/java/org/tikv/common/PDClient.java b/src/main/java/org/tikv/common/PDClient.java
index 695a1565b1c..1568a78e0ef 100644
--- a/src/main/java/org/tikv/common/PDClient.java
+++ b/src/main/java/org/tikv/common/PDClient.java
@@ -50,9 +50,12 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import org.apache.http.client.methods.CloseableHttpResponse;
@@ -122,6 +125,8 @@ public class PDClient extends AbstractGRPCClient<PDBlockingStub, PDFutureStub>
   private ConcurrentMap<Long, Double> tiflashReplicaMap;
   private HostMapping hostMapping;
   private long lastUpdateLeaderTime;
+  private final ExecutorService updateLeaderService = Executors.newSingleThreadExecutor();
+  private final AtomicBoolean updateLeaderNotify = new AtomicBoolean();
 
   public static final Histogram PD_GET_REGION_BY_KEY_REQUEST_LATENCY =
       HistogramUtils.buildDuration()
@@ -426,6 +431,8 @@ public void close() throws InterruptedException {
     if (channelFactory != null) {
       channelFactory.close();
     }
+
+    updateLeaderService.shutdownNow();
   }
 
   @VisibleForTesting
@@ -462,11 +469,7 @@ private GetMembersResponse doGetMembers(BackOffer backOffer, URI uri) {
   }
 
   private GetMembersResponse getMembers(BackOffer backOffer, URI uri) {
-    try {
-      return doGetMembers(backOffer, uri);
-    } catch (Exception e) {
-      return null;
-    }
+    return doGetMembers(backOffer, uri);
   }
 
   // return whether the leader has changed to target address `leaderUrlStr`.
@@ -518,7 +521,26 @@ synchronized boolean createFollowerClientWrapper(
     return true;
   }
 
-  public synchronized void updateLeaderOrForwardFollower(BackOffer backOffer) {
+  public void tryUpdateLeaderOrForwardFollower() {
+    if (updateLeaderNotify.compareAndSet(false, true)) {
+      try {
+        BackOffer backOffer = defaultBackOffer();
+        updateLeaderService.submit(
+            () -> {
+              try {
+                updateLeaderOrForwardFollower(backOffer);
+              } finally {
+                updateLeaderNotify.set(false);
+              }
+            });
+      } catch (RejectedExecutionException e) {
+        logger.error("PDClient is shutdown", e);
+        updateLeaderNotify.set(false);
+      }
+    }
+  }
+
+  private synchronized void updateLeaderOrForwardFollower(BackOffer backOffer) {
     if (System.currentTimeMillis() - lastUpdateLeaderTime < MIN_TRY_UPDATE_DURATION) {
       return;
     }
diff --git a/src/main/java/org/tikv/common/operation/PDErrorHandler.java b/src/main/java/org/tikv/common/operation/PDErrorHandler.java
index 4f9cc7fbabb..76c6a768644 100644
--- a/src/main/java/org/tikv/common/operation/PDErrorHandler.java
+++ b/src/main/java/org/tikv/common/operation/PDErrorHandler.java
@@ -26,6 +26,7 @@
 import org.tikv.common.PDClient;
 import org.tikv.common.exception.GrpcException;
 import org.tikv.common.exception.TiClientInternalException;
+import org.tikv.common.log.SlowLogSpan;
 import org.tikv.common.pd.PDError;
 import org.tikv.common.util.BackOffFunction;
 import org.tikv.common.util.BackOffer;
@@ -59,7 +60,12 @@ public boolean handleResponseError(BackOffer backOffer, RespT resp) {
         case PD_ERROR:
           backOffer.doBackOff(
               BackOffFunction.BackOffFuncType.BoPDRPC, new GrpcException(error.toString()));
-          client.updateLeaderOrForwardFollower(backOffer);
+          SlowLogSpan tryUpdateLeaderSpan = backOffer.getSlowLog().start("try_update_leader");
+          try {
+            client.tryUpdateLeaderOrForwardFollower();
+          } finally {
+            tryUpdateLeaderSpan.end();
+          }
           return true;
         case REGION_PEER_NOT_ELECTED:
           logger.debug(error.getMessage());
@@ -80,7 +86,12 @@ public boolean handleRequestError(BackOffer backOffer, Exception e) {
       return false;
     }
     backOffer.doBackOff(BackOffFunction.BackOffFuncType.BoPDRPC, e);
-    client.updateLeaderOrForwardFollower(backOffer);
+    SlowLogSpan updateLeaderSpan = backOffer.getSlowLog().start("try_update_leader");
+    try {
+      client.tryUpdateLeaderOrForwardFollower();
+    } finally {
+      updateLeaderSpan.end();
+    }
     return true;
   }
 }
diff --git a/src/main/java/org/tikv/common/region/RegionManager.java b/src/main/java/org/tikv/common/region/RegionManager.java
index 8c1624e42e0..44c81375107 100644
--- a/src/main/java/org/tikv/common/region/RegionManager.java
+++ b/src/main/java/org/tikv/common/region/RegionManager.java
@@ -182,7 +182,7 @@ public Pair<TiRegion, TiStore> getRegionStorePairByKey(ByteString key, TiStoreTy
   public Pair<TiRegion, TiStore> getRegionStorePairByKey(
       ByteString key, TiStoreType storeType, BackOffer backOffer) {
     TiRegion region = getRegionByKey(key, backOffer);
-    if (!region.isValid()) {
+    if (region == null || !region.isValid()) {
       throw new TiClientInternalException("Region invalid: " + region);
     }
 
diff --git a/src/main/java/org/tikv/common/region/RegionStoreClient.java b/src/main/java/org/tikv/common/region/RegionStoreClient.java
index ccc820891f1..ba742c872b0 100644
--- a/src/main/java/org/tikv/common/region/RegionStoreClient.java
+++ b/src/main/java/org/tikv/common/region/RegionStoreClient.java
@@ -1408,38 +1408,34 @@ public RegionStoreClient build(TiRegion region, TiStore store, TiStoreType store
           this);
     }
 
-    public synchronized RegionStoreClient build(TiRegion region, TiStore store)
-        throws GrpcException {
+    public RegionStoreClient build(TiRegion region, TiStore store) throws GrpcException {
       return build(region, store, TiStoreType.TiKV);
     }
 
-    public synchronized RegionStoreClient build(ByteString key) throws GrpcException {
+    public RegionStoreClient build(ByteString key) throws GrpcException {
       return build(key, TiStoreType.TiKV);
     }
 
-    public synchronized RegionStoreClient build(ByteString key, BackOffer backOffer)
-        throws GrpcException {
+    public RegionStoreClient build(ByteString key, BackOffer backOffer) throws GrpcException {
       return build(key, TiStoreType.TiKV, backOffer);
     }
 
-    public synchronized RegionStoreClient build(ByteString key, TiStoreType storeType)
-        throws GrpcException {
+    public RegionStoreClient build(ByteString key, TiStoreType storeType) throws GrpcException {
       return build(key, storeType, defaultBackOff());
     }
 
-    public synchronized RegionStoreClient build(
-        ByteString key, TiStoreType storeType, BackOffer backOffer) throws GrpcException {
+    public RegionStoreClient build(ByteString key, TiStoreType storeType, BackOffer backOffer)
+        throws GrpcException {
       Pair<TiRegion, TiStore> pair =
           regionManager.getRegionStorePairByKey(key, storeType, backOffer);
       return build(pair.first, pair.second, storeType);
     }
 
-    public synchronized RegionStoreClient build(TiRegion region) throws GrpcException {
+    public RegionStoreClient build(TiRegion region) throws GrpcException {
       return build(region, defaultBackOff());
     }
 
-    public synchronized RegionStoreClient build(TiRegion region, BackOffer backOffer)
-        throws GrpcException {
+    public RegionStoreClient build(TiRegion region, BackOffer backOffer) throws GrpcException {
       TiStore store = regionManager.getStoreById(region.getLeader().getStoreId(), backOffer);
       return build(region, store, TiStoreType.TiKV);
     }
diff --git a/src/test/java/org/tikv/common/PDClientV2MockTest.java b/src/test/java/org/tikv/common/PDClientV2MockTest.java
index 305cd101c38..af9884b415b 100644
--- a/src/test/java/org/tikv/common/PDClientV2MockTest.java
+++ b/src/test/java/org/tikv/common/PDClientV2MockTest.java
@@ -88,18 +88,16 @@ public void testGetRegionById() throws Exception {
     String start = "getRegionById";
     String end = "getRegionByIdEnd";
     leader.addGetRegionByIDListener(request -> makeGetRegionResponse(start, end));
-    try (PDClient client = createClient()) {
-      Metapb.Region r = client.getRegionByID(ConcreteBackOffer.newRawKVBackOff(), 1).first;
-      Assert.assertEquals(start, r.getStartKey().toStringUtf8());
-      Assert.assertEquals(end, r.getEndKey().toStringUtf8());
-    }
+    PDClient client = createClient();
+    Metapb.Region r = client.getRegionByID(ConcreteBackOffer.newRawKVBackOff(), 1).first;
+    Assert.assertEquals(start, r.getStartKey().toStringUtf8());
+    Assert.assertEquals(end, r.getEndKey().toStringUtf8());
 
     leader.addGetRegionByIDListener(request -> makeGetRegionResponse(start, ""));
-    try (PDClient client = createClient()) {
-      Metapb.Region r = client.getRegionByID(ConcreteBackOffer.newRawKVBackOff(), 1).first;
-      Assert.assertEquals(start, r.getStartKey().toStringUtf8());
-      Assert.assertEquals("", r.getEndKey().toStringUtf8());
-    }
+
+    r = client.getRegionByID(ConcreteBackOffer.newRawKVBackOff(), 1).first;
+    Assert.assertEquals(start, r.getStartKey().toStringUtf8());
+    Assert.assertEquals("", r.getEndKey().toStringUtf8());
   }
 
   @Test
@@ -113,15 +111,14 @@ public void testScanRegions() throws Exception {
                 .addRegions(Pdpb.Region.newBuilder().setRegion(makeRegion(start, end)).build())
                 .build());
 
-    try (PDClient client = createClient()) {
-      List<Region> regions =
-          client.scanRegions(
-              ConcreteBackOffer.newRawKVBackOff(), ByteString.EMPTY, ByteString.EMPTY, 1);
+    PDClient client = createClient();
+    List<Region> regions =
+        client.scanRegions(
+            ConcreteBackOffer.newRawKVBackOff(), ByteString.EMPTY, ByteString.EMPTY, 1);
 
-      for (Region r : regions) {
-        Assert.assertEquals(start, r.getRegion().getStartKey().toStringUtf8());
-        Assert.assertEquals(end, r.getRegion().getEndKey().toStringUtf8());
-      }
+    for (Region r : regions) {
+      Assert.assertEquals(start, r.getRegion().getStartKey().toStringUtf8());
+      Assert.assertEquals(end, r.getRegion().getEndKey().toStringUtf8());
     }
   }
 }
diff --git a/src/test/java/org/tikv/common/TimeoutTest.java b/src/test/java/org/tikv/common/TimeoutTest.java
index e0f3d01d1ce..33642c2ccba 100644
--- a/src/test/java/org/tikv/common/TimeoutTest.java
+++ b/src/test/java/org/tikv/common/TimeoutTest.java
@@ -52,9 +52,12 @@ public void testTimeoutInTime() {
     try (RawKVClient client = createClient()) {
       pdServers.get(0).stop();
       long start = System.currentTimeMillis();
-      client.get(ByteString.copyFromUtf8("key"));
+      try {
+        client.get(ByteString.copyFromUtf8("key"));
+      } catch (Exception ignore) {
+      }
       long end = System.currentTimeMillis();
-      Assert.assertTrue(end - start < session.getConf().getRawKVReadTimeoutInMS() * 2L);
+      Assert.assertTrue(end - start < (session.getConf().getRawKVReadTimeoutInMS() * 1.5));
     }
   }
 }