Difference between GRS and RA-GRS.

Question

I understood the concepts of GRS and RA-GRS.

GRS

• LRS on both regions.
• We cannot access the secondary region after the fail-over happens.

RA-GRS

• ZRS in primary region and LRS in secondary region
• Can access the secondary region before fail-over.

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Question - 1

My Question is the benefit of accessing the secondary region. What i didn't understood is, what is the benefit of having a read access to the secondary region.

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Question-2

I didn't understood the above information.

source - https://learn.microsoft.com/en-us/azure/storage/common/storage-disaster-recovery-guidance#microsoft-managed-failover.

So after the failover. What exactly happens to my resources? I know that during the failover the primary region failsover to the secondary region. This means the secondary region becomes the new primary region.
It says that when this happens, while the resources and data is transported the resource manager remains in the original primary region. So, then what is the use of even having this option if i cannot access my resources or modify them as needed.

What will happen to my primary region.

Thank You.

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Answer 1

Welcome to Microsoft Q&A platform and thanks for posting your question here.

Referring Question 1

Having read access to the secondary region in a geo-redundant storage configuration can provide several benefits, especially in scenarios where high availability and disaster recovery are critical. Here are some use cases for having read access to the secondary region:

Read Traffic Distribution:

By allowing read access to the secondary region, you can distribute read traffic across both primary and secondary regions. This can help balance the load on your storage system and improve overall performance.

High Availability:

In a geo-redundant storage setup, the secondary region serves as a standby in case of a failure in the primary region. Having read access to the secondary region ensures that your application can seamlessly switch to the secondary region for read operations in case of a regional outage.

Failover Testing:

During planned maintenance or disaster recovery drills, you can intentionally fail over to the secondary region for read access to test the resilience of your application. This helps ensure that your failover processes work as expected.

Load Balancing:

Some applications might use the secondary region for read-heavy workloads, effectively load balancing the read operations across both regions. This can be useful in scenarios where you want to optimize resource usage.

Enhanced Disaster Recovery:

In the event of a disaster affecting the primary region, having read access to the secondary region allows your application to continue serving read operations from the secondary region while recovery actions are taken in the primary region.

Improved Application Resilience:

Read access to the secondary region enhances the overall resilience of your application. If there are issues with the primary region, your application can continue to function for read operations using the secondary region.

Referring Question 2

The failover process is designed to prioritize the availability of your applications and data. While certain management operations may be limited in the original primary region immediately after failover, the main goal is to ensure that your applications can continue running and that your data is accessible in a geographically redundant manner.

Primary Region State: After a failover, the original primary region becomes the new secondary region. It serves as a standby in case you need to fail back or for additional redundancy.

Why Have This Option:

High Availability: The primary reason for having this failover option is to ensure high availability. If the primary region is impacted by a disaster, the failover allows your application to continue functioning with minimal downtime.

Data Redundancy: By having a secondary region, your data is replicated and available in multiple geographic locations. This enhances the durability and availability of your data.

Disaster Recovery: The failover process is part of a disaster recovery strategy. It allows you to quickly redirect traffic and operations to a secondary region in case of a catastrophic event.

Hope this helps.

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