Oracle Data Guard - Step-by-Step - Configuring FSFO - Data Guard Observer and Auto-Failover

Hello viewers, welcome to the Step-by-Step Oracle Data Guard series and in this Part-8, we are going to learn about F-S-F-O Observer or DG Observer configuration and how to use it for automatic failover in a disaster scenario.
So what is a FSFO observer ? It is a third entity between the primary and standby database in a Data Guard configuration. It is actually a low-footprint OCI client software built into the Data Guard Broker Command Line Interface and like any other client, may be run on a different hardware platform than the database servers. Its primary job is to continuously check the status of the primary database by pinging it.
When due to a disaster in the primary site, the observer is unable to get a ping response from the primary or when certain conditions are fulfilled such as the primary is not reachable from the standby, corrupted Control file, corrupted dictionary or datafile write errors etc, then it waits for a predefined amount of seconds set as threshold and initiates a failover to the standby DB set as the FSFO target for the primary. But it does not stop there yet, it will keep checking if the old primary becomes accessible again and if it finds it accessible again, it automatically initiates a reinstate of the old primary as the new standby leading to a robust high availability solution.
Oracle data guard is an indispensable part of oracle's high availability solutions. In a real world scenario the Primary and Physical standby databases reside on geographically different locations or different data centers to make sure that even if one region goes completely down, your database is still available and intact. In this tutorial and the series I am covering various topics on oracle Data Guard, like architecture, implementation, administration, management, monitoring etc. Each of these topics may need one or more tutorials to cover it completely. I assume you are already an oracle dba or familiar with at least the basics of oracle database architecture. I will keep everything simple so there won't be any difficulty in understanding the concepts even if you are a beginner.
I am using a virtual environment for demonstration purpose.
Commands and SQLs used:
docs.google.com/document/d/13...
Previous Parts in this Series:
Part-1: Create a Physical Standby using OEM
• Oracle DataGuard - Ste...
Part-2: DG Architecture, Configuration, Broker, Switchover, Failover
• Oracle DataGuard - Ste...
Part-3: Administration, Management, Monitoring using OEM
• Oracle DataGuard - Ste...
Part-4: Standby Log Gap, Detect, Alert and Resolve
• Oracle Data Guard - St...
Part-5: Primary Database Protection Modes
• Oracle Data Guard - St...
Part-6: Different Standby Database Modes
• Oracle Data Guard - St...
Part-7: Configuring RMAN Backups in Standby
• Oracle Data Guard - St...
My other series on CZcams:
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Mastering OEM 13c (Full Series):
• Mastering OEM 13c
Setting up OEM Notification, Monitoring and Alerting:
• OEM Monitoring and Ale...
Oracle VirtualBox Virtual Machines:
• VBox Virtual Machines