Fixing some typos

Author: pas256

source/tutorial/deploy-replica-set.txt

@@ -21,14 +21,14 @@ system failures. A replica set of this size provides sufficient
 capacity to host many distributed read operations. While MongoDB's
 replica set functionality provides a great deal of flexibility and
 specific definable node behaviors or types, it's best to avoid this
-additional complexity your application requires the functionality.
+additional complexity until your application requires the functionality.
 
 Requirements
 ------------
 
 Three distinct systems, so that each system can run its own instance
 of :program:`mongod`. For test systems you can run all three instances
-of the :program:`mongod` process on a local sys em.e. a laptop) or
+of the :program:`mongod` process on a local system. e.g. a laptop) or
 within a virtual instance. For production environments, you should
 endeavor to maintain as much separation between the nodes: Deploy
 replica set members on distinct hardware, and on systems that draw
@@ -72,7 +72,7 @@ following options for more information: :option:`--port <mongod --port>`,
 
    If you're running each :program:`mongod` instance on a distinct
    system, you can omit the :option:`--port <mongod --port>`
-   option. YOu will also need to specify the :option:`--bind_ip
+   option. You will also need to specify the :option:`--bind_ip
    <mongod --bind_ip>` option.
 
 Log in with the :program:`mongo` shell to the first host. If you're