Update plugin documentation

Remove master/slave reference from the documentation.
Adapt documentation to the current Gerrit architecture
by removing reference to the database.

Change-Id: I87b78ab5dbf4723faf6c18e71060d75c3c99e6cd
diff --git a/src/main/resources/Documentation/about.md b/src/main/resources/Documentation/about.md
index 1d1a02b..fd0b56e 100644
--- a/src/main/resources/Documentation/about.md
+++ b/src/main/resources/Documentation/about.md
@@ -1,20 +1,19 @@
 
 This plugin allows making Gerrit highly available by having redundant Gerrit
-masters.
+active/passive instances.
 
-The masters must be:
+The Gerrit instances must be:
 
-* connecting to the same database
 * sharing the git repositories using a shared file system (e.g. NFS)
 * behind a load balancer (e.g. HAProxy)
 
-Currently, the mode supported is one primary (active) master and multiple backup
-(passive) masters but eventually the plan is to support `n` active masters. In
-the active/passive mode, the active master is handling all traffic while the
-passives are kept updated to be always ready to take over.
+Currently, the mode supported is one active instance and multiple backup
+(passive) instances but eventually the plan is to support `n` active instances.
+In the active/passive mode, the active instance is handling all traffic while
+the passives are kept updated to be always ready to take over.
 
-Even if database and git repositories are shared by the masters, there are a few
-areas of concern in order to be able to switch traffic between masters in a
+Even if git repositories are shared by the instances, there are a few areas
+of concern in order to be able to switch traffic between instances in a
 transparent manner from the user's perspective. The 4 areas of concern are
 things that Gerrit stores either in memory or locally in the review site:
 
@@ -23,69 +22,67 @@
 * stream-events
 * web sessions
 
-They need either to be shared or kept local to each master but synchronized.
-This plugin needs to be installed in all the masters and it will take care of sharing
-or synchronizing them.
+They need either to be shared or kept local to each instances but synchronized.
+This plugin needs to be installed in all the instances and it will take care of
+sharing or synchronizing them.
 
 #### Caches
-Every time a cache eviction occurs in one of the masters, the eviction will be
-forwarded the other masters so their caches do not contain stale entries.
+Every time a cache eviction occurs in one of the instances, the eviction will be
+forwarded the other nodes so their caches do not contain stale entries.
 
 #### Secondary indexes
-Every time the secondary index is modified in one of the masters, e.g., a change
-is added, updated or removed from the index, the others master's index are
-updated accordingly. This way, both indexes are kept synchronized.
+Every time the secondary index is modified in one of the instances, e.g., a change
+is added, updated or removed from the index, the others instances index are updated
+accordingly. This way, both indexes are kept synchronized.
 
 #### Stream events
-Every time a stream event occurs in one of the masters (see [more events info]
-(https://gerrit-review.googlesource.com/Documentation/cmd-stream-events.html#events)),
-the event is forwarded to the other masters which re-plays it. This way, the
-output of the stream-events command is the same, no matter which master a client
-is connected to.
+Every time a stream event occurs in one of the instances
+(see [more events info](https://gerrit-review.googlesource.com/Documentation/cmd-stream-events.html#events)),
+the event is forwarded to the other instances which re-plays it. This way, the output
+of the stream-events command is the same, no matter which  instance a client is
+connected to.
 
 #### Web session
 The built-in Gerrit H2 based web session cache is replaced with a file based
-implementation that is shared amongst the masters.
+implementation that is shared amongst the instances.
 
 ## Setup
 
 Prerequisites:
 
-* Unique database server must be accessible from all the masters
 * Git repositories must be located on a shared file system
 * A directory on a shared file system must be available for @PLUGIN@ to use
 
-For the masters:
+For the instances:
 
-* Configure the database section in gerrit.config to use the shared database
 * Configure gerrit.basePath in gerrit.config to the shared repositories location
 * Configure gerrit.serverId in gerrit.config based on [config](config.md)'s introduction
 * Install and configure this @PLUGIN@ plugin [further](config.md) or based on below.
 
 Here is an example of the minimal @PLUGIN@.config:
 
-Primary master
+Active instance
 
 ```
 [main]
-  sharedDirectory = /directory/accessible/from/both/masters
+  sharedDirectory = /directory/accessible/from/both/nodes
 
 [peerInfo "static"]
-  url = http://backupMasterHost1:8081/
+  url = http://backupNodeHost1:8081/
 
 [http]
   user = username
   password = password
 ```
 
-Backup master
+Backup instance
 
 ```
 [main]
-  sharedDirectory = /directory/accessible/from/both/masters
+  sharedDirectory = /directory/accessible/from/both/nodes
 
 [peerInfo "static"]
-  url = http://primaryMasterHost:8080/
+  url = http://primaryNodeHost:8080/
 
 [http]
   user = username
@@ -94,10 +91,10 @@
 
 ### HA replica site
 
-It is possible to create a copy of the master site and configure both sites to run
-in HA mode as peers. This is possible when the directory where the copy will be
-created is accessible from this machine. Such a replica site can be created by
-means of a gerrit [site init](../../../Documentation/pgm-init.html) step,
+It is possible to create a copy of the instance site and configure both
+sites to run in HA mode as peers. This is possible when the directory where
+the copy will be created is accessible from this machine. Such a replica site
+can be created by means of a gerrit [site init](../../../Documentation/pgm-init.html) step,
 contributed by the plugin under its init section.
 
 This init step is optional but defaults to creating the replica. If you want to
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index 0ead279..ac3b400 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -55,7 +55,7 @@
 ```
 
 ```main.sharedDirectory```
-:   Path to a directory accessible from both master instances.
+:   Path to a directory accessible from both instances.
     When given as a relative path, then it is resolved against the $SITE_PATH
     or Gerrit server. For example, if $SITE_PATH is "/gerrit/root" and
     sharedDirectory is given as "shared/dir" then the real path of the shared