1 files changed, 56 insertions, 0 deletions
diff --git a/jstests/sharding/conf_server_write_concern.js b/jstests/sharding/conf_server_write_concern.js
new file mode 100644
index 00000000000..30002ae9f46
--- /dev/null
+++ b/jstests/sharding/conf_server_write_concern.js
@@ -0,0 +1,56 @@
+/**
+ * Test write concern with w parameter when writing directly to the config servers will
+ * not cause an error.
+ */
+function writeToConfigTest(){
+    var st = new ShardingTest({ shards: 2 });
+    var confDB = st.s.getDB( 'config' );
+
+    assert.writeOK(confDB.settings.update({ _id: 'balancer' },
+                                          { $set: { stopped: true }},
+                                          { writeConcern: { w: 'majority' }}));
+
+    // w:1 should still work
+    assert.writeOK(confDB.settings.update({ _id: 'balancer' },
+                                          { $set: { stopped: true }},
+                                          { writeConcern: { w: 1 }}));
+
+    st.stop();
+}
+
+/**
+ * Test write concern with w parameter will not cause an error when writes to mongos
+ * would trigger writes to config servers (in this test, split chunks is used).
+ */
+function configTest( configCount ){
+    var st = new ShardingTest({ shards: 1, config: configCount,
+          rs: { oplogSize: 10 }, other: { chunkSize: 1 }});
+     
+    var mongos = st.s;
+    var testDB = mongos.getDB( 'test' );
+    var coll = testDB.user;
+     
+    testDB.adminCommand({ enableSharding: testDB.getName() });
+    testDB.adminCommand({ shardCollection: coll.getFullName(), key: { x: 1 }});
+     
+    var chunkCount = function() {
+        return mongos.getDB( 'config' ).chunks.find().count();
+    };
+     
+    var initChunks = chunkCount();
+    var currChunks = initChunks;
+    var gleObj = null;
+    var x = 0;
+     
+    while( currChunks <= initChunks ){
+        assert.writeOK(coll.insert({ x: x++ }, { writeConcern: { w: 'majority' }}));
+        currChunks = chunkCount();
+    }
+
+    st.stop();
+}
+
+writeToConfigTest();
+configTest( 1 );
+configTest( 3 ); // sync cluster config servers
+