DOC-11830 Backup Service references ns_server instead of Cluster Manager

modules/learn/pages/services-and-indexes/services/backup-service.adoc

@@ -39,7 +39,7 @@ See xref:backup-restore:enterprise-backup-restore.adoc[cbbackupmgr] for more inf
 == Backup Service Architecture
 
 When there are multiple Backup Service nodes in the cluster, 
-Couchbase Server elects one of them to be the leader.
+the Cluster Manager elects one of them to be the leader.
 The leader is responsible for:
 
 * Dispatching backup tasks.
@@ -48,7 +48,7 @@ The leader is responsible for:
 * Ensuring that all Backup Service nodes can reach the global storage locations.
 
 If the leader becomes unresponsive or fails over, the Backup Service stops until a rebalance takes place.
-During the rebalance, Couchbase Server elects a new leader.
+During the rebalance, the Cluster Manager elects a new leader.
 The Backup Service then resumes running on the surviving Backup Service nodes.
 
 [#plans]
@@ -72,7 +72,7 @@ In addition to just backing up data, a backup task can also merge backups.
 [#repositories]
 == Repositories
 
-A repository is a location where Couchbase Server can store backup data. 
+A repository is a location where the Backup Service can store backup data.
 You associate a repository with a plan.
 You must set several options to define the repository, including:
 
@@ -103,11 +103,11 @@ You can restore data to its original keyspace or apply a mapping to restore it t
 == Archiving and Importing
 
 If you no longer need a repository to perform backups, you can archive it. 
-You can still read the backed up data in an archived repository.
+You can still read the backed-up data in an archived repository.
 However, the Backup Service cannot perform further backups to the repository. 
 
-If you delete a repository but do not delete the data it contains you can import the data back into the cluster.
-After importing the data, you can read the data but as with archived repositories, the Backup Service cannot write backups to it.
+If you delete a repository but do not delete the data it contains, you can import the data back into the cluster.
+After importing the data, you can read the data, but as with archived repositories, the Backup Service cannot write backups to it.
 
 [#avoiding-task-overlap]
 == Avoiding Task Overlap
@@ -116,17 +116,17 @@ The Backup Service allows you to schedule automated tasks at intervals as small
 However, you should be cautious about using intervals under fifteen minutes.
 You must make sure the interval is large enough to allow each task enough time to finish before the next task is scheduled to start.
 
-Several conditions can cause a backup task to take longer than anticipated. 
+Several conditions can cause a backup task to take longer than expected.
 Having many backups in the same repository can make the process of populating the backup's staging directory slower.
 Spikes in network latency can also cause a backup to take longer than usual.
 
-The backup Service runs only a single task at a time.
+The Backup Service runs only a single task at a time.
 If another instance a task is scheduled to start while a previous instance is still running, the Backup Service refuses to start the new instance.
 Instead, the instance of the task fails to start.
 If a backup task is scheduled to start while a different task is already running, the Backup Service queues the new task until the existing task finishes.
 
 A backup task can also fail if the underlying `cbbackupmgr` process it calls to perform the backup fails. 
-When run directly or by a Backup Service task, the `cbbackupmgr` tool takes a lock on the repository into which it  backing up data.
+When run directly or by a Backup Service task, the `cbbackupmgr` tool takes a lock on the repository into which it's  backing up data.
 This lock prevents any other instance of the `cbbackupmgr` tool to storing data into the repository.
 If the instance of `cbbackupmgr` started by a Backup Service task exits due to a lock on its repository, the backup task fails.