Did you just realize that your Mule Application requires horizontal scaling? Well, thats easy – just go to CloudHub Runtime Manager, select your application and change the “Workers” count from 1 to either 2, 3 or 4. If numbers are grayed out, then you might have to adjust the “Worker Size”, or purchase additional capacity from MuleSoft. So, what is the issue then?
At the time of the blog post, based on Mule documentation, if you are using only 1 worker and if you want to apply static IP, then you can simply navigate to “Static IPs” section in Runtime Manager and allocate the static IP address. The issue is when you want to apply Static IP addresses for more than 1 workers for various reasons including IP whitelisting. Based on Mule documentation you cannot apply static IPs if you are using more than 1 worker.
From Mule Documentation: “Static IPs are not supported for private IP addresses inside a CloudHub VPC and it is only supported for applications with 1 worker.”
So, how to solve this issue? You can first navigate to “Static IPs” section, and select “Use Static IP” checkbox. Now go back to “Runtime” section and select appropriate number of “Workers”, now click on “Apply Changes” button. Now, your application will be deployed to multiple workers and Mule will allocate and assign static IPs. Only downside is that you cannot pre-allocate multiple IP addresses.
From June 2017, MuleSoft was enabling “Multiple Static IPs” feature on case-by-case basis for your CloudHub orgs, but since September 2017, MuleSoft has enabled this feature for all the orgs by default. Here is the catch, there are some pre-conditions: Make sure your CloudHub subscription allows deploying application on multiple workers, you have enough vCores available for deployment, you have enough Static IPs available in the pool and you have Cloud Fabric feature enabled for your CloudHub subscription.
So, now you can scale you Mule Applications horizontally based on load requirements and for added reliability. Hopefully, MuleSoft will update their documentation soon, but until then we can call this Multiple Static IP addresses as a “Hidden Feature” of the CloudHub! Hope this post helps.