1 files changed, 50 insertions, 0 deletions
diff --git a/jstests/sharding/mongos_validate_backoff.js b/jstests/sharding/mongos_validate_backoff.js
new file mode 100644
index 00000000000..9b1ecfc5c50
--- /dev/null
+++ b/jstests/sharding/mongos_validate_backoff.js
@@ -0,0 +1,50 @@
+//
+// Ensures that single mongos shard-key errors are fast, but slow down when many are triggered  
+//
+
+var st = new ShardingTest({ shards : 1, mongos : 1 })
+
+var mongos = st.s0
+var admin = mongos.getDB( "admin" )
+var coll = mongos.getCollection( "foo.bar" )
+
+printjson( admin.runCommand({ enableSharding : coll.getDB() + "" }) )
+
+coll.ensureIndex({ shardKey : 1 })
+printjson( admin.runCommand({ shardCollection : coll + "", key : { shardKey : 1 } }) )
+
+var timeBadInsert = function(){
+
+    var start = new Date().getTime()
+
+    // Bad insert, no shard key
+    coll.insert({ hello : "world" })
+    assert.neq( null, coll.getDB().getLastError() )
+
+    var end = new Date().getTime()    
+
+    return end - start
+}
+
+// Loop over this test a few times, to ensure that the error counters get reset if we don't have
+// bad inserts over a long enough time.
+for( var test = 0; test < 3; test++ ){
+    
+    var firstWait = timeBadInsert()
+    var lastWait = 0
+    
+    for( var i = 0; i < 20; i++ ){
+        printjson( lastWait = timeBadInsert() )
+    }
+    
+    // Kind a heuristic test, we want to make sure that the error wait after sleeping is much less
+    // than the error wait after a lot of errors
+    assert.gt( lastWait, firstWait * 2 * 2 * 2 * 2 )
+    
+    // Sleeping for long enough to reset our exponential counter
+    sleep( 3000 )
+}
+
+jsTest.log( "DONE!" )
+
+st.stop()