Added changes auto abandon option, updated README

Closes-Bug: PROD-15768
Change-Id: I79f1ec07f4ff2b03ba276712aa1b303b4aa403b0
diff --git a/README.rst b/README.rst
index 7e7db07..dc04ece 100644
--- a/README.rst
+++ b/README.rst
@@ -60,6 +60,11 @@
           engine: http
           address: https://gerrit-releases.storage.googleapis.com/gerrit-2.12.4.war
           hash: sha256=45786a920a929c6258de6461bcf03ddec8925577bd485905f102ceb6e5e1e47c
+              receive_timeout: 5min
+        sshd:
+          threads: 64
+          batch_threads: 16
+          max_connections_per_user: 64
         database:
           engine: postgresql
           host: localhost
@@ -67,6 +72,17 @@
           name: gerrit
           user: gerrit
           password: ${_param:postgresql_gerrit_password}
+          pool_limit: 250
+          pool_max_idle: 16 
+
+Gerrit change auto abandon
+
+.. code-block:: yaml
+
+    gerrit:
+      server:
+        change_cleanup:
+          abandon_after: 3months
 
 
 Gerrit client enforcing groups
diff --git a/gerrit/files/gerrit.config b/gerrit/files/gerrit.config
index 99af419..881abc0 100644
--- a/gerrit/files/gerrit.config
+++ b/gerrit/files/gerrit.config
@@ -214,6 +214,11 @@
 
 {% endif %}
 
+{% if server.change_cleanup is defined %}
+[changeCleanup]
+    abandonAfter = {{ server.change_cleanup.get('abandon_after', 0) }}
+{% endif %}
+
 [groups]
     newGroupsVisibleToAll = {{ server.get('new_groups_visible_to_all', False) }}