AppFog (the company formerly known as PhpFog) has become the latest enthusiastic adopter of CloudFoundry to go to General Availability with a value-added implementation of the open source CloudFoundry.org stack.  The key differentiator is the RAM-based pricing policy around the Public Cloud offering – roughly $25 per GByte per month (first 2Gbytes are Free).

Whilst PhpFog remains and is still widely used, and will continue to be AppFog’s recommended route for PhP-only shops (assuming such things exist), the clue is in the change of company name. AppFog is no longer just PhP. Like most of the CloudFoundry-derived PaaS offerings this is a “Polyglot” i.e. a multi-language platform with multiple framework support.  It also runs on multiple IaaS clouds – Rackspace, Amazon, Azure, HP at point of GA, and it is available as  multi-tenanted PaaS (the default website signup) as well as single-tenanted PaaS and on-premise PaaS (Private Cloud).

AppFog runs both Open Source frameworks and .NET, using a technology which we know isn’t Iron Foundry (as used by Stackato) and which AppFog refer to as “Linux Containers”.  We await additional information from AppFog on the technology.  AppFog has a very neat quick-start web interface, and a CLI for upload. Unlike PhpFog there is no dependency on GitHub. The two features we didn’t yet see in AppFog that are present in competitive offerings are Autoscaling and Chargeback APIs.  We also don’t have a clear view on how security is handled in multitenancy.

The key differentiator of this GA release in a maturing marketplace of PaaS offerings seems to be to provide a simple one-stop-shop for buying public PaaS, the underlying IaaS and any third-party technologies.  You only ever get one bill and it’s from AppFog. It runs at the same price even if you mix multiple backend infrastructure vendors – Rackspace, Amazon, Azure, HP – all the same price. If one of them falls over (that’ll never happen 😉 ) you can migrate to another one at the touch of a button.

Monitoring and Management are optional extras provided by third-party vendors through reseller arrangements, and the ecosystem is already quite broad.

  • Blitz – a self-service cloud-based performance testing platform
  • ClearDB and Xeround- for hosted MySQL
  • CloudMailin for and Mailgun to handle email,
  • MongoHQ and MongoLabs for hosted MongoDB
  • New Relic for Application Performance Monitoring,
  • Searchify for hosted search.

The AppFog Public PaaS is also differentiated in pricing – both in terms of the overall low cost, and the clarity of pricing in comparison to alternatives (including direct use of an IaaS).  The free offering (2GBytes) is much more meaningful than, for example the 613 MByte t1.micro instance available under Amazon EC2 (which will probably run WordPress, but are useless for any significant application framework). In fact in general there doesn’t seem to be any obvious way of matching AppFog pricing using the publicly-available pricing of the IaaS vendors concerned (for example a 4G Windows or Linux VM on  Azure will cost you $115pm as opposed to $100pm for 4GBytes on AppFog running on Azure) and AppFog claim they always use the fastest servers available , and they don’t charge you for storage or bandwidth, or IP addresses.  To achieve this price point,  it seems AppFog perhaps is doing a lot of over-committing of resources on the VMs on which the multi-tenanted PaaS is implemented.  It has almost certainly also done some bulk purchase deals to keep pricing down, leveraging its installed base of PhP deployed applications to providing an initial volume purchase that some other startup cloud vendors can’t.

VMware’s own version of CloudFoundry (CloudFoundry.com) is still in Beta and the free trial version is also limited to 2Gbytes, so is currently price-compatible with AppFog.  It remains to be seen whether VMware will match match AppFog pricing when it goes to GA.  Also, VMware’s infrastructure is built on a pure VMware stack and is thus single-sourced at the IaaS and Virtual Infrastructure level.  Again we await a sign from VMware that this may change.