AlwaysOn Sync setup

Question

Experts :

As of now we have one server on which one SQL Instance is there which needs to be converted to alwayson sync replication between 2 Alwayson instances in a DC(By following the required steps).

On the existing SQL Instance Is there a way to calculate the change of data(Databasewise in MB/GB) for judging the amount of data flow which will happen between the always on setup which will be coming up.

Answer 1

Hi,

The Always on availability group transfers the transaction log records that occurred in the primary replica to the secondary replica, and then the secondary replica harden and redo these transactions.

With the secondary replica configured in synchronous commit mode, the primary replica needs to confirm that the secondary replica has completed log harden before it can commit the transaction (this may have some performance impact). When you want to evaluate the data size, rate and other factors synchronized by the Always on Availability Group, I suggest that you first configure an asynchronous commit replica, it will almost not affect the performance of the primary replica. After the configuration is completed, use the AlwaysOn performance counter(SQL Server, Availability Replica, SQL Server, Database Replica), or AlwaysOn related DMVs and dashborad to monitor these factors, and whether there are any delays, queues, etc. After that, you can change this replica to synchronous commit mode, or add another synchronous commit replica.

Answer 2

This is SQL 2017/2019