If you need a cloud-based service bus or a simple to use queue/topic/routing/pub-sub service, then Azure Service Bus is a very good choice at a reasonable price and performance. Typically on-premise we'd use RabbitMQ because it "just works", but if you're building a "cloud-first" application, then this is the one to go with. It's especially easy to integrate with if you're already embedded in the Microsoft ecosystem.
WebSphere DataPower Gateway is really beneficial if you are trying to integrate two or more systems. It provides you with comfort and peace of mind by creating a DMZ zone for the services which are going out of the intranet to hit external clients APIs. It is greatly recommended if you have a very high volume service or API which is being used by a majority of clients because it has a dedicated physical box present which takes care of memory, CPU and all such stuff. So, all your transactions happen at wire-speed.
Acting as a basic queuing service it works very well.
One of the best parts is that Azure Service Bus can work over HTTPS which helps in strict firewall situations. There is a performance hit if you choose to use HTTPS.
The routing capabilities are quite good when using topics and subscriptions. You can apply filters using a pseudo-SQL-like language though the correlation filters are quick and easy options.
Costs are very reasonable at low-ish volumes. If you're processing 10's of millions of messages a month... it may be a different story.
The most obvious thing that DataPower does exceptionally well is security. All the built-in supported security capabilities allow us to isolate most security tasks to DataPower and as a result "protect" down steam services/systems to have to deal with security.
DataPower is very good at protocol conversion and as it is usually used on the edge allows you to narrow down the protocols used between the companies public and private networks.
The appliance concept makes maintenance, recovery and, management so much simpler.
The old interface is being really missed by our team as the new WebUI interface is not that intuitive or easy to work with. It takes a lot of time to load. There should be an inbuilt wizard for creating a Rest service as well like there is for an XML based service.
IBM support is very knowledgeable but it's not that easy to reach them. They don't release the fix patches very soon which also becomes a big issue in certain situations where critical projects are involved.
Lastly, DataPower has its steep learning curve and it requires time and effort on your end to gain full control and make the most of the advanced features which it offers. Finding the right resource in the market is not that easy.
RabbitMQ is simple and awesome... but so is Azure Service Bus. Both accomplish the same thing but in different environments. If you're building a cloud-native application - especially one that is serverless by design - Azure Service Bus is the only real choice in Azure. It works well, it's performance, and it's reasonably priced in the Standard tier. From our testing, RMQ is more performant, but it's hard to compare service-based implementations vs RMQ installed on VMs.
It has really taken our business to the next level. We have expanded and integrated with so many new vendors and for all those integrations DataPower is serving as our security gateway.
We don't have to depend on any other tool for doing the load balancing of the incoming requests as that is also taken care inside the WebSphere DataPower Gateway box itself, thereby distributing the load equally.
It has made our platform much more secure, uniform and robust to deal with any kind of incoming message format or threat as well due to its latest security mechanisms and huge processing power.
