1 files changed, 16 insertions, 49 deletions

diff --git a/src/mongo/db/repl/bgsync.cpp b/src/mongo/db/repl/bgsync.cpp
index 56e5ab0e0c0..c0211a21022 100644
--- a/src/mongo/db/repl/bgsync.cpp
+++ b/src/mongo/db/repl/bgsync.cpp
@@ -270,6 +270,7 @@ void BackgroundSync::_produce(OperationContext* opCtx) {
     // find a target to sync from the last optime fetched
     OpTime lastOpTimeFetched;
     HostAndPort source;
+    HostAndPort oldSource = _syncSourceHost;
     SyncSourceResolverResponse syncSourceResp;
     {
         const OpTime minValidSaved = storageInterface->getMinValid(opCtx);
@@ -332,6 +333,16 @@ void BackgroundSync::_produce(OperationContext* opCtx) {
         stdx::lock_guard<stdx::mutex> lock(_mutex);
         _syncSourceHost = syncSourceResp.getSyncSource();
         source = _syncSourceHost;
+
+        // If our sync source has not changed, it is likely caused by our heartbeat data map being
+        // out of date. In that case we sleep for 1 second to reduce the amount we spin waiting
+        // for our map to update.
+        if (oldSource == source) {
+            log() << "Chose same sync source candidate as last time, " << source
+                  << ". Sleeping for 1 second to avoid immediately choosing a new sync source for "
+                     "the same reason as last time.";
+            sleepsecs(1);
+        }
     } else {
         if (!syncSourceResp.isOK()) {
             log() << "failed to find sync source, received error "
@@ -367,7 +378,6 @@ void BackgroundSync::_produce(OperationContext* opCtx) {
     Status fetcherReturnStatus = Status::OK();
     DataReplicatorExternalStateBackgroundSync dataReplicatorExternalState(
         _replCoord, _replicationCoordinatorExternalState, this);
-    auto rbidCopyForFetcher = syncSourceResp.rbid;  // OplogFetcher's callback modifies this.
     OplogFetcher* oplogFetcher;
     try {
         auto executor = _replicationCoordinatorExternalState->getTaskExecutor();
@@ -385,13 +395,14 @@ void BackgroundSync::_produce(OperationContext* opCtx) {
             NamespaceString(rsOplogName),
             config,
             _replicationCoordinatorExternalState->getOplogFetcherMaxFetcherRestarts(),
+            syncSourceResp.rbid,
+            true /* requireFresherSyncSource */,
             &dataReplicatorExternalState,
             stdx::bind(&BackgroundSync::_enqueueDocuments,
                        this,
                        stdx::placeholders::_1,
                        stdx::placeholders::_2,
-                       stdx::placeholders::_3,
-                       &rbidCopyForFetcher),
+                       stdx::placeholders::_3),
             onOplogFetcherShutdownCallbackFn);
         oplogFetcher = _oplogFetcher.get();
     } catch (const mongo::DBException& ex) {
@@ -428,8 +439,7 @@ void BackgroundSync::_produce(OperationContext* opCtx) {
         // Do not blacklist the server here, it will be blacklisted when we try to reuse it,
         // if it can't return a matching oplog start from the last fetch oplog ts field.
         return;
-    } else if (fetcherReturnStatus.code() == ErrorCodes::OplogStartMissing ||
-               fetcherReturnStatus.code() == ErrorCodes::RemoteOplogStale) {
+    } else if (fetcherReturnStatus.code() == ErrorCodes::OplogStartMissing) {
         if (_replCoord->getMemberState().primary()) {
             // TODO: Abort catchup mode early if rollback detected.
             warning() << "Rollback situation detected in catch-up mode; catch-up mode will end.";
@@ -503,50 +513,7 @@ void BackgroundSync::_produce(OperationContext* opCtx) {
 
 Status BackgroundSync::_enqueueDocuments(Fetcher::Documents::const_iterator begin,
                                          Fetcher::Documents::const_iterator end,
-                                         const OplogFetcher::DocumentsInfo& info,
-                                         boost::optional<int>* requiredRBID) {
-    // Once we establish our cursor, we need to ensure that our upstream node hasn't rolled back
-    // since that could cause it to not have our required minValid point. The cursor will be killed
-    // if the upstream node rolls back so we don't need to keep checking. This must be blocking
-    // since the Fetcher doesn't give us a way to defer sending the getmores after we return.
-    if (*requiredRBID) {
-        auto rbidStatus = Status(ErrorCodes::InternalError, "");
-        auto handle =
-            _replicationCoordinatorExternalState->getTaskExecutor()->scheduleRemoteCommand(
-                {getSyncTarget(), "admin", BSON("replSetGetRBID" << 1), nullptr},
-                [&](const executor::TaskExecutor::RemoteCommandCallbackArgs& rbidReply) {
-                    rbidStatus = rbidReply.response.status;
-                    if (!rbidStatus.isOK())
-                        return;
-
-                    rbidStatus = getStatusFromCommandResult(rbidReply.response.data);
-                    if (!rbidStatus.isOK())
-                        return;
-
-                    const auto rbidElem = rbidReply.response.data["rbid"];
-                    if (rbidElem.type() != NumberInt) {
-                        rbidStatus = Status(ErrorCodes::BadValue,
-                                            str::stream() << "Upstream node returned an "
-                                                          << "rbid with invalid type "
-                                                          << rbidElem.type());
-                        return;
-                    }
-                    if (rbidElem.Int() != **requiredRBID) {
-                        rbidStatus = Status(ErrorCodes::BadValue,
-                                            "Upstream node rolled back after verifying "
-                                            "that it had our MinValid point. Retrying.");
-                    }
-                });
-        if (!handle.isOK())
-            return handle.getStatus();
-
-        _replicationCoordinatorExternalState->getTaskExecutor()->wait(handle.getValue());
-        if (!rbidStatus.isOK())
-            return rbidStatus;
-
-        requiredRBID->reset();  // Don't come back to this block while on this cursor.
-    }
-
+                                         const OplogFetcher::DocumentsInfo& info) {
     // If this is the first batch of operations returned from the query, "toApplyDocumentCount" will
     // be one fewer than "networkDocumentCount" because the first document (which was applied
     // previously) is skipped.