[DOC] Update documentation in regard of ONAP services monitoring

Change-Id: Ib121b469822c024f63e230139f4f13ec46ef49ab
Issue-ID: OOM-2924
Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>
diff --git a/docs/InstallGuide.rst b/docs/InstallGuide.rst
index 2359b0c..9edcbf6 100644
--- a/docs/InstallGuide.rst
+++ b/docs/InstallGuide.rst
@@ -638,6 +638,21 @@
 
 After the Offline Platform installation process is complete, the Stack will be deployed into its own kubernetes and helm namespace **kube-prometheus**.
 
+ONAP Services Monitoring
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Some ONAP services export application metrics which can be scraped by Prometheus by leveraging the ServiceMonitor objects. Offline Platform provides a curated set of Grafana panels for monitoring ONAP's mariadb-galera chart. To enable mariadb-galera monitoring provide the following helm values in ``application_configuration.yml``::
+
+    overrides:
+      mariadb-galera:
+        metrics:
+          serviceMonitor:
+            enabled: true
+            basicAuth:
+              enabled: false
+
+To access the Galera/MariaDB dashboard navigate to *Dashboards -> Manage -> ONAP -> Galera/MariaDB* in Grafana UI.
+
 Accessing Grafana dashboard
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~