Updated diagram with watchdog component

Updated broken link
Added a redundancy for pgbackrest disclaimer
updated bare-minimum limitation about losing nodes

Author: nastena1606

docs/_images/diagrams/ha-recommended.svg

@@ -34,7 +34,7 @@ The components in this architecture are:
 
 ### Services layer
 
-- pgBackRest - the backup and restore solution for PostgreSQL
+- pgBackRest - the backup and restore solution for PostgreSQL. It should also be redundant to eliminate a single point of failure.
 
 - (Optional) Percona Monitoring and Management (PMM) - the solution to monitor the health of your cluster 
 
@@ -46,10 +46,10 @@ There may be constraints to use the [recommended reference architecture](#archit
 
 Using such architecture has the following limitations:
 
-* This setup only protects against a one node failure, either a database or a etcd node. Losing one node results in the read-only database.
+* This setup only protects against a one node failure, either a database or a etcd node. Losing more than one node results in the read-only database.
 * The application must be able to connect to multiple database nodes and fail over to the new primary in the case of outage.
 * The application must act as the load-balancer. It must be able to determine read/write and read-only requests and distribute them across the cluster. 
-* The `pbBackRest` component is optional but highly-recommended for disaster recovery.
+* The `pbBackRest` component is optional but highly-recommended for disaster recovery. To eliminate a single point of failure, it should also be redundant but we're not discussing redundancy in this solution. [Contact us](https://www.percona.com/about/contact) to discuss it if this is the requirement for you.
 
 ## Additional reading
 

docs/solutions/ha-architecture.md

@@ -7,7 +7,7 @@ But what does it mean, high availability? And how to achieve it? This document a
 After reading this document, you will learn the following:
 
 * [what is high availability](#what-is-high-availability)
-* the recommended [reference architecture]((ha-architecture.md)) to achieve it
+* the recommended [reference architecture](ha-architecture.md) to achieve it
 * how to deploy it using our step-by-step deployment guides for each component. The deployment instructions focus on the minimalistic approach to high availability that we recommend. It also gives instructions how to deploy additional components that you can add when your infrastructure grows.
 * how to verify that your high availability deployment works as expected, providing replication and failover with the [testing guidelines](ha-test.md)