-> Disaster Recovery scenario is as below,
- PRIMARY DATA CENTRE goes down.
- The databases on Server JBSERVER2 should be made online and have the application connect to Database Server JBSERVER2.
- Failback Availability group back to JBSERVER1 when PRIMARY DATA CENTRE comes online.
- The changes made by the Application on JBSERVER2\IN2014 should be relayed to JBSERVER1\IN2014
-> Checking the current AlwaysON setup in SQL Server Management Studio,
-> The Database JB_DB contains a table named Table5, which we will use for testing.
USE [JB_DB] GO CREATE TABLE [dbo].[Table5]( [sno] [int] IDENTITY(1,1) NOT NULL, [sname] [char](2000) NULL, [sname1] [char](2000) NULL, [sname2] [char](2000) NULL, PRIMARY KEY CLUSTERED ( [sno] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] Set nocount on insert into Table5 values ('a','b','c') go 10002
-> Checking the row count for object Table5,
-> The PRIMARY DATA CENTRE goes down. 2 votes are lost as Database Server JBSERVER1 and file share witness is down. Now that 2 votes out of 3 votes are lost, the cluster goes down.
-> Checking the SQL Server instance and Eventlogs on JBSERVER2 when the Primary Data Centre is down.
-> Implementing Force Quorum on JBSERVER2.
-> Checking the SQL Server Instance after Force Quorum,
-> I will suspend the data movement now,
-> Right-click the availability group to be failed over, and select Failover.
-> Checking the SQL Server Instance after the failover with data loss.
-> The application can now connect to SQL Server Instance JBSERVER2\IN2014 using the Listener and use it. Let us insert a single row to the table for testing and make sure if it can be seen later after the failback.
insert into Table5 values (‘a’,’b’,’c’)
-> The PRIMARY DATA CENTRE comes online. Database Server JBSERVER1 and File witness are online now.
-> Connecting to JBSERVER1\IN2014 and Suspending the data movement,
-> On SQL Server Instance JBSERVER2\IN2014, we will resume the data movement.
-> On SQL Server Instance JBSERVER1\IN2014, we will resume the data movement.
-> Checking the SQL Server Instance now,
-> We will failback the Alwayson Availability group to JBSERVER1\IN2014,
-> Checking the row count for object Table5 on JBSERVER1\IN2014 after failback,
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