Fix pd retry not recovered for 60s (#182)

Signed-off-by: birdstorm <samuelwyf@hotmail.com>

Author: birdstorm

src/main/java/org/tikv/common/PDClient.java

@@ -418,7 +418,7 @@ synchronized boolean switchLeader(List<String> leaderURLs) {
     return createLeaderWrapper(leaderUrlStr);
   }
 
-  private boolean createLeaderWrapper(String leaderUrlStr) {
+  private synchronized boolean createLeaderWrapper(String leaderUrlStr) {
     try {
       URI newLeader = addrToUri(leaderUrlStr);
       leaderUrlStr = uriToAddr(newLeader);

src/main/java/org/tikv/common/operation/PDErrorHandler.java

@@ -73,6 +73,7 @@ public boolean handleResponseError(BackOffer backOffer, RespT resp) {
   @Override
   public boolean handleRequestError(BackOffer backOffer, Exception e) {
     backOffer.doBackOff(BackOffFunction.BackOffFuncType.BoPDRPC, e);
+    client.updateLeader();
     return true;
   }
 }

src/test/java/org/tikv/common/PDMockServer.java

@@ -43,7 +43,7 @@ public void addGetMemberResp(GetMembersResponse r) {
   @Override
   public void getMembers(GetMembersRequest request, StreamObserver<GetMembersResponse> resp) {
     try {
-      resp.onNext(getMembersResp.removeFirst().get());
+      resp.onNext(getMembersResp.getFirst().get());
       resp.onCompleted();
     } catch (Exception e) {
       resp.onError(Status.INTERNAL.asRuntimeException());