Update source/release-notes/2.2.txt

Improve explanation for sharded cluster upgrade.

Author: matulef

source/release-notes/2.2.txt

@@ -80,41 +80,33 @@ procedure:
 Upgrading a Shard Cluster
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-If your cluster uses authentication, use the following upgrade
-procedure:
+We recommend the following upgrade procedure for a sharded cluster:
+
+- :ref:`disable the balancer <sharding-balancing-disable-temporally>`,
 
 - Upgrade all :program:`mongos` instances *first*, in any order.
 
 - Upgrade all of the :program:`mongod` config server instances *one at
-  a time*. When you have *fewer* than *three* config servers active,
-  the cluster metadata will be read-only which will prevent (and abort)
-  all chunk migrations and chunk splits.
+  a time* using the :ref:`stand alone <2.2-upgrade-standalone>` procedure.  
+  When you have *fewer* than *three* config servers active, the cluster 
+  metadata will be read-only which will prevent (and abort)
+  all chunk migrations and chunk splits. 
 
-- Upgrade all remaining cluster components. Use the :ref:`upgrade
+- Upgrade all remaining cluster components, using the :ref:`upgrade
   procedure for replica sets <2.2-upgrade-replica-set>` for each of
-  the shards and the :ref:`stand alone <2.2-upgrade-standalone>`
-  procedure for each of the config servers. You may upgrade the
-  components of your cluster in any order.
+  the shards.
 
-If your cluster *does not* use authentication, you may upgrade the
-components of the cluster in any order, using the :ref:`upgrade
-procedure for replica sets <2.2-upgrade-replica-set>` for each of the
-shards and the :ref:`stand alone <2.2-upgrade-standalone>` procedure
-for each of the config servers.
+ - re-enable the balancer.
 
-.. note::
+If your cluster uses authentication, you must upgrade the components in 
+the order above.  If your cluster does not use authentication, you can 
+upgrade the mongos instances, config servers, and shards in any order. 
 
-   Balancing does not work in *mixed* 2.0 and 2.2 deployments. For the
-   best results:
-
-   - :ref:`disable the balancer <sharding-balancing-disable-temporally>`,
+.. note::
 
-   - upgrade the :program:`mongos`, if using authentication,
+   Balancing does not currently work in *mixed* 2.0.x and 2.2.0 deployments. 
 
-   - upgrade all :program:`mongod` instances, including all shard
-     components and configuration instances in the cluster, and
 
-   - re-enable the balancer.
 
 Changes
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