Hi, want to understand if OE provide support for high availability application by its own. can Replication database work as a load balance? I mean if I have a replication database, then in case of a fail over can the application utilize the replicated DB by switching from primary DB to the replication DB and continue functioning till the time primary DB came up?
To my understanding Native 4GL client will not get notify when the Production database goes down. You need to manually redirect it to DR database. But SQL you can give set of connection urls in the "datadirect" driver so you can redirect the logins to DR site in a failure of production server.
OE does not provide any application or framework to support utilising Replication DB for high availability application (or zero downtime). On the other hand this should not be very difficult to read data from Replication database if the primary data source is down, but you have to still do work for routing the traffic to Replication DB. This could be a manual changeover or dynamic using "proutil db-name -C busy". Else if you are looking purely for load balancing then the reading data can always be directed to Replication DB. Having said that it is very important to note that you should not write to Replication DB and that's the tricky part depending on how and what you are looking to implement.
In future i.e. with OE version 12 (releasing probably in first half of 2018) Progress might release the active-active DB clustering which aims at providing zero application downtime. You can contact Progress for more info about this.