When I reviewed the Cloud Foundry PaaS (platform as a service) last summer, I concentrated on the open source, Pivotal, and ActiveState implementations. In this review, I’ll look at IBM Bluemix, a multitenanted PaaS hosted on SoftLayer, which combines Cloud Foundry with an improved online UI and services from IBM and third parties.
The most distinctive services on Bluemix are based on Watson, a cognitive system that provides natural language processing, hypothesis generation and evaluation, and dynamic learning. Several of the other services and integrations in Bluemix fill gaps in the open source version of Cloud Foundry -- for example, autoscaling, mobile, big data, and enterprise integration services.
Note that the gaps have been filled without forking the Cloud Foundry code. In fact, Bala Rajaraman, the CTO of Bluemix, has told me flat out: “We will not fork.” The cf application configuration command-line program I installed for open source Cloud Foundry and Pivotal CF is the same as the one for Bluemix. The bosh PaaS configuration command-line program I installed for open source Cloud Foundry is the same as what the Bluemix engineers use internally – but users of Bluemix will never need to learn bosh, as IBM’s intention with Bluemix is to shield users from PaaS administration, focus on service, and allow users to simply build apps.
I approve of this attitude. As a developer, I found learning bosh a struggle, and I felt the heavy lifting in configuring a PaaS ought to be left to operations. For me, the promise of PaaS and devops is low-friction configuration and management of infrastructure in aid of getting software built and deployed. Making a developer spend a significant portion of his or her time on the operational cruft needed to set up a PaaS defeats the fundamental purpose of having a PaaS. At the same time, I like the ability to run a single-VM “microcloud” PaaS privately on a laptop for experiments, which is why I also see the value of ActiveState Stackato and downloadable PaaS VM images.
Because Bluemix is built on unmodified Cloud Foundry, it shares all of the Cloud Foundry architecture: Droplets, DEAs (Droplet Execution Agents), buildpacks, and so on, running in a virtual machine. The Cloud Foundry portion is shown in the light blue VM box in the lower left of the architecture diagram below (Figure 1).
Figure 1. The Bluemix architecture diagram. Note that Bluemix is basically a stock Cloud Foundry virtual machine plus an improved user interface and additional services.
