we want to add third vRealize Automation Appliance to dedicated it at the scheduled tasks.
For example when it's necessary to update all Business Group : Reservation, Entitlements, DAY2, etc.... This task call vRA REST API to make the job.
Sometimes when the scheduled task run the vRA REST API become done, doesn't respond and this impact our customers.
To doesn't impact the Production portal we want to add a third appliance as a not a member of load balancer.
If we change our scheduled tasks to use a specific REST API on the third appliance we think it's a good solution.
But just one question, when we have a third appliance it's mandatory to enable Synchronous Mode on PostgreSQL database ?
Thx for your feedback.
Generally the purpose of adding a third appliance, is to enable automatic fail-over of postgreSQL database.
For that you need to enable Synchronous replication between all three nodes to leverage the feature.
Since, your requirement is different and you do not require automatic fail-over, you can deploy a third appliance without turning synchronous replication on.
Whether you should take this approach is a completely different matter all-together.