Reworded cluster monitoring

Author: mbeijen

admin/cluster-monitoring.rst

@@ -10,8 +10,8 @@ Introduction
 Cluster monitoring provides aspects of monitoring needed in high availability
 setups. There is a special class of object in |product_name| - Cluster.
 
-:term:`DCIs<DCI>` defined on cluster object are automatically applied to it's
-nodes. Cluster allows to aggregate data from it's nodes, e.g. to calculate
+:term:`DCIs<DCI>` defined on a cluster object are automatically applied to its
+nodes. A cluster allows to aggregate data from its nodes, e.g. to calculate
 sum or average for a metric that is collected from all nodes.
-Cluster can adequately collect data from services as they move from from
+A cluster can adequately collect data from services as they move from
 one node to another, providing uninterrupted data collection.