diff --git a/ts/00_commitinfo_data.ts b/ts/00_commitinfo_data.ts
new file mode 100644
index 0000000..d853ae1
--- /dev/null
+++ b/ts/00_commitinfo_data.ts
@@ -0,0 +1,8 @@
+/**
+ * autocreated commitinfo by @pushrocks/commitinfo
+ */
+export const commitinfo = {
+  name: '@pushrocks/smartmongo',
+  version: '1.0.9',
+  description: 'create a local mongodb for testing'
+}
diff --git a/ts/index.ts b/ts/index.ts
index 329400d..36fe2d1 100644
--- a/ts/index.ts
+++ b/ts/index.ts
@@ -11,25 +11,25 @@ export class SmartMongo {
   // INSTANCE
   private _readyDeferred = plugins.smartpromise.defer();
   public readyPromise = this._readyDeferred.promise;
-  public mongod: plugins.mongoPlugin.MongoMemoryServer;
+  public mongoReplicaSet: plugins.mongoPlugin.MongoMemoryReplSet;
 
   constructor() {
   }
 
-  public async start() {
-    this.mongod = await plugins.mongoPlugin.MongoMemoryServer.create();
+  public async start(countArg: number = 4) {
+    this.mongoReplicaSet = await plugins.mongoPlugin.MongoMemoryReplSet.create({ replSet: { count: countArg } });
     this._readyDeferred.resolve();
-    console.log('mongod started');
+    console.log(`mongoReplicaSet with ${countArg} replicas started.`);
   }
 
   public async getMongoDescriptor(): Promise<plugins.smartdata.IMongoDescriptor> {
     await this.readyPromise;
     return {
-      mongoDbUrl: this.mongod.getUri(),
+      mongoDbUrl: this.mongoReplicaSet.getUri(),
     }
   }
 
   public async stop() {
-    await this.mongod.stop(true);
+    await this.mongoReplicaSet.stop(true);
   }
 }
\ No newline at end of file