SERVER-25146 JS replset dbhash hook fails when checking nindexes with a collection containing a background index

1 files changed, 23 insertions, 0 deletions

diff --git a/jstests/hooks/check_repl_dbhash.js b/jstests/hooks/check_repl_dbhash.js
index 76504d4a1f8..0cece1b037b 100644
--- a/jstests/hooks/check_repl_dbhash.js
+++ b/jstests/hooks/check_repl_dbhash.js
@@ -80,6 +80,29 @@ function checkDBHashesFsyncLocked(rst) {
     var primary = rst.getPrimary();
     assert(primary, 'calling getPrimary() failed');
 
+    function generateUniqueDbName(dbNameSet, prefix) {
+        var uniqueDbName;
+        Random.setRandomSeed();
+        do {
+            uniqueDbName = prefix + Random.randInt(100000);
+        } while (dbNameSet.has(uniqueDbName));
+        return uniqueDbName;
+    }
+
+    // Since we cannot determine if there is a background index in progress (SERVER-25176), we flush
+    // indexing as follows:
+    //  1. Drop a dummy collection
+    //  2. Create a foreground index on the dummy collection
+    //  3. Insert a document into the dummy collection with a writeConcern for all nodes
+    var dbNames = new Set(primary.getDBNames());
+    var uniqueDbName = generateUniqueDbName(dbNames, "flush_all_background_indexes_");
+
+    var dummyColl = primary.getDB(uniqueDbName).dummy;
+    dummyColl.drop();
+    assert.commandWorked(dummyColl.createIndex({x: 1}));
+    assert.writeOK(
+        dummyColl.insert({x: 1}, {writeConcern: {w: rst.nodes.length, wtimeout: 5 * 60 * 1000}}));
+
     var activeException = false;
 
     try {