---
title: "Rolling upgrade scenario: Two OneSpan Authentication Server instances using individual databases"
slug: "oas-ag-rolling-upgrade-scenario-two-onespan-authentication-server-instances-using-individual-databases-3-28"
updated: 2025-07-04T10:04:17Z
published: 2025-07-07T13:30:26Z
canonical: "docs.onespan.com/oas-ag-rolling-upgrade-scenario-two-onespan-authentication-server-instances-using-individual-databases-3-28"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.onespan.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Rolling upgrade scenario: Two OneSpan Authentication Server instances using individual databases

## About this scenario

This scenario describes an environment with the following setup:

- There are two OneSpan Authentication Server instances: server A and server B.
- Each OneSpan Authentication Server instance has its own database.
- User load is distributed evenly between all OneSpan Authentication Server instances using a third-party solution.
- Two-way replication is enabled between all instances to ensure consistency of data across databases

![Rolling upgrade scenario: Two servers using individual databases and replication](https://cdn.document360.io/038f59a7-abd0-4c14-9de7-3434d28b49fd/Images/Documentation/2SRV_Individual_DB.png)

Figure: Rolling upgrade scenario: Two servers using individual databases and replication

## Before you begin

- Verify that you have addressed the different usability and user load issues related to a rolling upgrade (see [General considerations](/sec/docs/oas-ag-rolling-upgrades-3-28#general-considerations)).
- In this scenario you will be requested to configure, break, and restore replication between different OneSpan Authentication Server instances. For more information about replication during rolling upgrades, see [Replication](/sec/docs/oas-ag-rolling-upgrades-3-28#replication).

## Walkthrough: Performing a rolling upgrade on two servers with individual databases

Performing a rolling upgrade on two servers with individual databases

1. Remove the load from server A.
2. [Break replication](/sec/docs/oas-ag-rolling-upgrades-3-28#replication) from server B to server A.
3. Wait until the replication queue on server A is empty.
4. Stop the OneSpan Authentication Server service on server A.
5. [Break replication](/sec/docs/oas-ag-rolling-upgrades-3-28#replication) from server A to server B.
6. Upgrade OneSpan Authentication Server on server A.
7. [Restore replication](/sec/docs/oas-ag-rolling-upgrades-3-28#replication) from server B to server A.
8. Wait until the replication queue on server B is empty.
9. Restore the load to server A.
10. Remove the load from server B.
11. Wait until the replication queue on server B is empty.
12. Stop the OneSpan Authentication Server service on server B.
13. [Break replication](/sec/docs/oas-ag-rolling-upgrades-3-28#replication) from server B to server A.
14. Upgrade OneSpan Authentication Server on server B.
15. [Restore replication](/sec/docs/oas-ag-rolling-upgrades-3-28#replication) from server A to server B.
16. [Restore replication](/sec/docs/oas-ag-rolling-upgrades-3-28#replication) from server B to server A.
17. Wait until the replication queue on server A is empty.
18. Restore load to server B.