Hi
Let me explain the scenario first.
We have on-premise large Oracle database above which lots of WCF services are written to read/write business transactions. Everything on-Premise so far. Now we have applications in cloud (Azure + AWS) which needed to use these on-Premise WCF services so we achieve this via Azure Service Bus Relay. Current flow is:-
Cloud Application (Azure + AWS) -> WCF Service (Azure) -> Azure Service Bus -> WCF Service (On-Premise) -> Oracle (On-Premise)
Now the plan is to get rid of Azure Service Bus and bring the APP Servers hosting the WCF (on-Premise) service into Azure VPN communicating with our on-Premise Oracle via VPN tunnel. These WCF services inside our VPN will then be exposed via Baracuda WAF firewall in Azure. The flow now would be:-
Cloud Application (Azure+AWS) -> APIGEE(SAAS) -> WCF Service (Azure VPN) -> Oracle (On-Premise)
Now after this premise, my question is specifically around which part if more fragile & expensive. A structured WCF response coming via ServiceBus or APP Servers in cloud (Azure VPN communiction is over the internet) talking to On-Premise database.
Here are my reasons to somehow think the later is not such a great idea.
1. First, I think a WCF response is more reliable than an Oracle data access connection. Although I have no evidence to support this theory.
2. Secondly, the communication with On-Premise Oracle from cloud would be an expensive affair as when you get data out from any database, you cast that into proper business object and leave the un-necessary bit out which reduces the amount of data travelling over the wire. In VPN solution, raw data will travel to cloud and then it will be casted into business logic and sometimes you make a second call later on the basis of checking few things which obviously will have more latency or response time.
3. Which is more easy to implement, failover in Service Bus or VPN solution. This is more of a question actually?
Apologies for such a long business case but needed to explain the situation for proper suggestions.
Thanks in advance.
Regards
Piyush
Piyush Gupta