How to simulate failover is happening or not

Question

HA is enabled. now wanted to check if failover happens are not. How to simulate this?

Answer 1

Hi Molagara, Bhanu P •,

Welcome to Microsoft Q&A forum and thanks for using Azure services.

As I understand, you want to simulate failover in Azure Database for PostgreSQL.

Flexible server provides two methods for you to perform on-demand failover to the standby server. These are useful if you want to test the failover time and downtime impact for your applications and if you want to fail over to the preferred availability zone.

1). Forced Failover

You can use this feature to simulate an unplanned outage scenario while running your production workload and observe your application downtime. Alternatively, in rare case where your primary server becomes unresponsive for whatever reason, you may use this feature. This feature brings the primary server down and initiates the failover workflow in which the standby promote operation is performed. Once the standby completes the recovery process till the last committed data, it is promoted to be the primary server. DNS records are updated and your application can connect to the promoted primary server. Your application can continue to write to the primary while a new standby server is established in the background and that doesn't impact the uptime.

2). Planned Failover

You can use this feature for failing over to the standby server with reduced downtime. For example, after an unplanned failover, your primary could be on a different availability zone than the application, and you want to bring the primary server back to the previous zone to colocate with your application.

When executing this feature, the standby server is first prepared to make sure it is caught up with recent transactions allowing the application to continue to perform read/writes. The standby is then promoted and the connections to the primary are severed. Your application can continue to write to the primary while a new standby server is established in the background. The following are the steps involved with planned failover.

Considerations while performing on-demand failovers

• The overall end-to-end operation time may be seen longer than the actual downtime experienced by the application. Please observe the downtime from the application perspective.
• Please do not perform immediate, back-to-back failovers. Wait for at least 15-20 minutes between failovers, which will allow the new standby server to be fully established.
• For the planned failover with reduced downtime, it is recommended to perform during low activity period.

Detailed steps are mentioned here in the documentation: On-Demand Failover Hope this helps. If this answers your query, do click Accept Answer and Mark Helpful for the same. And, if you have any further query do let us know.

Thank you.