What is a difference between Read Scale Out and active geo replications

Question

Hi Team,

I would like to know the difference between Read Scale Out setting and having active geo replication for performance.

Pros and Cons

Thanks

Answer 1

Hi Nitya V •,

Welcome to Microsoft Q&A forum.

As I understand, you want to know the difference between Read Scale Out and Active Geo Replication.

Where business process transactions typically are frequent and small, transactions from analytical workloads typically read many data and run for a long time. Mixing these two types of transactions in the same database often lead to performance problems. The analytical transactions can cause locking issues, which in turn impose waiting time for business processes. This condition also may disrupt the data cache in the database. Data will essentially be moved from the cache that speeds up business process transactions.

If you run the Business Central database in a High Availability architecture, you can use the built-in Read Scale-Out feature in Azure SQL Database or SQL Server to load-balance read-only workloads. Read-Scale-Out uses the capacity of a read-only replica instead of sharing the read-write replica (also known as the primary database). This way, read-only workloads like reports, queries, and API pages, are isolated from the main read-write workload codeunits. So they won't affect the performance of business processes. As an added bonus, read-only workloads will run on a dedicated database and their performance will likely be better.

Reference: https://learn.microsoft.com/en-us/dynamics365/business-central/dev-itpro/administration/database-read-scale-out-overview

Active geo-replication is designed as a business continuity solution. Active geo-replication lets you perform quick disaster recovery of individual databases if there's a regional disaster or a large scale outage. Once geo-replication is set up, you can initiate a geo-failover to a geo-secondary in a different Azure region. The geo-failover is initiated programmatically by the application or manually by the user.

Refer: https://learn.microsoft.com/en-us/azure/azure-sql/database/active-geo-replication-overview?view=azuresql

Thanks