SERVER-27808 backup_restore.js waits secondary nodes to agree on primary before adding hidden node to replica set configr3.5.2

2 files changed, 15 insertions, 11 deletions

diff --git a/jstests/noPassthrough/libs/backup_restore.js b/jstests/noPassthrough/libs/backup_restore.js
index 645d5cba362..73ee3e64cc4 100644
--- a/jstests/noPassthrough/libs/backup_restore.js
+++ b/jstests/noPassthrough/libs/backup_restore.js
@@ -260,10 +260,13 @@ var BackupRestoreTest = function(options) {
         rst.waitForState(rst.getSecondaries(), ReplSetTest.State.SECONDARY);
 
         // Add new hidden node to replSetTest
+        jsTestLog('Starting new hidden node (but do not add to replica set) with dbpath ' +
+                  hiddenDbpath + '.');
         var hiddenCfg =
             {noCleanData: true, oplogSize: 1024, dbpath: hiddenDbpath, replSet: replSetName};
-        rst.add(hiddenCfg);
-        var hiddenHost = rst.nodes[numNodes].host;
+        var nodesBeforeAddingHiddenMember = rst.nodes.slice();
+        var hiddenNode = rst.add(hiddenCfg);
+        var hiddenHost = hiddenNode.host;
 
         // Verify if dbHash is the same on hidden secondary for crudDb
         // Note the dbhash can only run when the DB is inactive to get a result
@@ -273,8 +276,7 @@ var BackupRestoreTest = function(options) {
                 try {
                     // Need to hammer this since the node can disconnect connections as it is
                     // starting up into REMOVED replication state.
-                    return (dbHash ===
-                            rst.nodes[numNodes].getDB(crudDb).runCommand({dbhash: 1}).md5);
+                    return (dbHash === hiddenNode.getDB(crudDb).runCommand({dbhash: 1}).md5);
                 } catch (e) {
                     return false;
                 }
@@ -282,6 +284,9 @@ var BackupRestoreTest = function(options) {
         }
 
         // Add new hidden secondary to replica set
+        jsTestLog('Adding new hidden node ' + hiddenHost + ' to replica set.');
+        rst.awaitNodesAgreeOnPrimary(ReplSetTest.kDefaultTimeoutMS, nodesBeforeAddingHiddenMember);
+        primary = rst.getPrimary();
         var rsConfig = primary.getDB("local").system.replset.findOne();
         rsConfig.version += 1;
         var hiddenMember = {_id: numNodes, host: hiddenHost, priority: 0, hidden: true};
@@ -290,8 +295,7 @@ var BackupRestoreTest = function(options) {
                              testName + ' failed to reconfigure replSet ' + tojson(rsConfig));
 
         // Wait up to 5 minutes until the new hidden node is in state RECOVERING.
-        rst.waitForState(rst.nodes[numNodes],
-                         [ReplSetTest.State.RECOVERING, ReplSetTest.State.SECONDARY]);
+        rst.waitForState(hiddenNode, [ReplSetTest.State.RECOVERING, ReplSetTest.State.SECONDARY]);
 
         // Stop CRUD client and FSM client.
         assert(checkProgram(crudPid), testName + ' CRUD client was not running at end of test');
@@ -300,7 +304,7 @@ var BackupRestoreTest = function(options) {
         stopMongoProgramByPid(fsmPid);
 
         // Wait up to 5 minutes until the new hidden node is in state SECONDARY.
-        rst.waitForState(rst.nodes[numNodes], ReplSetTest.State.SECONDARY);
+        rst.waitForState(hiddenNode, ReplSetTest.State.SECONDARY);
 
         // Wait for secondaries to finish catching up before shutting down.
         primary = rst.getPrimary();
diff --git a/src/mongo/shell/replsettest.js b/src/mongo/shell/replsettest.js
index 0be088cdc42..81ccdcd45d0 100644
--- a/src/mongo/shell/replsettest.js
+++ b/src/mongo/shell/replsettest.js
@@ -539,15 +539,15 @@ var ReplSetTest = function(opts) {
     /**
      * Blocks until all nodes agree on who the primary is.
      */
-    this.awaitNodesAgreeOnPrimary = function(timeout) {
+    this.awaitNodesAgreeOnPrimary = function(timeout, nodes) {
         timeout = timeout || self.kDefaultTimeoutMS;
+        nodes = nodes || self.nodes;
 
         assert.soonNoExcept(function() {
             var primary = -1;
 
-            for (var i = 0; i < self.nodes.length; i++) {
-                var replSetGetStatus =
-                    self.nodes[i].getDB("admin").runCommand({replSetGetStatus: 1});
+            for (var i = 0; i < nodes.length; i++) {
+                var replSetGetStatus = nodes[i].getDB("admin").runCommand({replSetGetStatus: 1});
                 var nodesPrimary = -1;
                 for (var j = 0; j < replSetGetStatus.members.length; j++) {
                     if (replSetGetStatus.members[j].state === ReplSetTest.State.PRIMARY) {