1 files changed, 33 insertions, 14 deletions

diff --git a/src/mongo/db/repl/sync_source_feedback.cpp b/src/mongo/db/repl/sync_source_feedback.cpp
index 7c08a04be27..43b84f45e38 100644
--- a/src/mongo/db/repl/sync_source_feedback.cpp
+++ b/src/mongo/db/repl/sync_source_feedback.cpp
@@ -60,6 +60,7 @@ namespace repl {
 void SyncSourceFeedback::_resetConnection() {
     LOG(1) << "resetting connection in sync source feedback";
     _connection.reset();
+    _fallBackToOldUpdatePosition = false;
 }
 
 bool SyncSourceFeedback::replAuthenticate() {
@@ -105,18 +106,24 @@ void SyncSourceFeedback::forwardSlaveProgress() {
     _cond.notify_all();
 }
 
-Status SyncSourceFeedback::updateUpstream(OperationContext* txn) {
+Status SyncSourceFeedback::updateUpstream(OperationContext* txn, bool oldStyle) {
     auto replCoord = repl::ReplicationCoordinator::get(txn);
     if (replCoord->getMemberState().primary()) {
-        // primary has no one to update to
+        // Primary has no one to send updates to.
         return Status::OK();
     }
     BSONObjBuilder cmd;
     {
         stdx::unique_lock<stdx::mutex> lock(_mtx);
-        // the command could not be created, likely because the node was removed from the set
-        if (!replCoord->prepareReplSetUpdatePositionCommand(&cmd)) {
-            return Status::OK();
+        // The command could not be created, likely because this node was removed from the set.
+        if (!oldStyle) {
+            if (!replCoord->prepareReplSetUpdatePositionCommand(&cmd)) {
+                return Status::OK();
+            }
+        } else {
+            if (!replCoord->prepareOldReplSetUpdatePositionCommand(&cmd)) {
+                return Status::OK();
+            }
         }
     }
     BSONObj res;
@@ -125,8 +132,9 @@ Status SyncSourceFeedback::updateUpstream(OperationContext* txn) {
     try {
         _connection->runCommand("admin", cmd.obj(), res);
     } catch (const DBException& e) {
-        log() << "SyncSourceFeedback error sending update: " << e.what() << endl;
-        // blacklist sync target for .5 seconds and find a new one
+        log() << "SyncSourceFeedback error sending " << (oldStyle ? "old style " : "")
+              << "update: " << e.what();
+        // Blacklist sync target for .5 seconds and find a new one.
         replCoord->blacklistSyncSource(_syncTarget, Date_t::now() + Milliseconds(500));
         BackgroundSync::get()->clearSyncTarget();
         _resetConnection();
@@ -135,11 +143,15 @@ Status SyncSourceFeedback::updateUpstream(OperationContext* txn) {
 
     Status status = Command::getStatusFromCommandResult(res);
     if (!status.isOK()) {
-        log() << "SyncSourceFeedback error sending update, response: " << res.toString() << endl;
-        // blacklist sync target for .5 seconds and find a new one, unless we were rejected due
-        // to the syncsource having a newer config
-        if (status != ErrorCodes::InvalidReplicaSetConfig || res["configVersion"].eoo() ||
-            res["configVersion"].numberLong() < replCoord->getConfig().getConfigVersion()) {
+        log() << "SyncSourceFeedback error sending " << (oldStyle ? "old style " : "")
+              << "update, response: " << res.toString();
+        if (status == ErrorCodes::BadValue && !oldStyle) {
+            log() << "SyncSourceFeedback falling back to old style UpdatePosition command";
+            _fallBackToOldUpdatePosition = true;
+        } else if (status != ErrorCodes::InvalidReplicaSetConfig || res["configVersion"].eoo() ||
+                   res["configVersion"].numberLong() < replCoord->getConfig().getConfigVersion()) {
+            // Blacklist sync target for .5 seconds and find a new one, unless we were rejected due
+            // to the syncsource having a newer config.
             replCoord->blacklistSyncSource(_syncTarget, Date_t::now() + Milliseconds(500));
             BackgroundSync::get()->clearSyncTarget();
             _resetConnection();
@@ -195,9 +207,16 @@ void SyncSourceFeedback::run() {
                 continue;
             }
         }
-        Status status = updateUpstream(txn.get());
+        bool oldFallBackValue = _fallBackToOldUpdatePosition;
+        Status status = updateUpstream(txn.get(), _fallBackToOldUpdatePosition);
         if (!status.isOK()) {
-            log() << "updateUpstream failed: " << status << ", will retry";
+            if (_fallBackToOldUpdatePosition != oldFallBackValue) {
+                stdx::unique_lock<stdx::mutex> lock(_mtx);
+                _positionChanged = true;
+            } else {
+                log() << (_fallBackToOldUpdatePosition ? "old style " : "") << "updateUpstream"
+                      << " failed: " << status << ", will retry";
+            }
         }
     }
 }