Category Archives: DevOps

GAE Traffic Splitting

Interesting addition to the Google App Engine (GAE) platform in release 1.6.3:  Traffic Splitting lets you run several versions of your application (using a DNS sub-domain for each version) and choose to direct a certain percentage of requests to a specific version. This lets you, among other things, slowly phase in your updates and test the result on a small set of users.

That’s nice, but until I read the documentation for the feature I had assumed (and hoped) it was something else.

Rather than using traffic splitting to test different versions of my app (something which the platform now makes convenient but which I could have implemented on my own), it would be nice if that mechanism could be used to test updates to the GAE platform itself. As described in “Come for the PaaS Functional Model, stay for the Cloud Operational Model“, it’s wishful thinking to assume that changes to the PaaS platform (an update applied by Google admins) cannot have a negative effect on your application. In other words, “When NoOps meets Murphy’s Law, my money is on Murphy“.

What would be nice is if Google could give application owners advanced warning of a platform change and let them use the Traffic Splitting feature to direct a portion of the incoming requests to application instances running on the new platform. And also a way to include the platform version in all log messages.

Here’s the issue as I described it in the aforementioned “Cloud Operational Model” post:

In other words, if a patch or update is worth testing in a staging environment if you were to apply it on-premise, what makes you think that it’s less likely to cause a problem if it’s the Cloud provider who rolls it out? Sure, in most cases it will work just fine and you can sing the praise of “NoOps”. Until the day when things go wrong, your users are affected and you’re taken completely off-guard. Good luck debugging that problem, when you don’t even know that an infrastructure change is being rolled out and when it might not even have been rolled out uniformly across all instances of your application.

How is that handled in your provider’s Operational Model? Do you have visibility into the change schedule? Do you have the option to test your application on the new infrastructure or to at least influence in any way how and when the change gets rolled out to your instances?

Hopefully, the addition of Traffic Splitting to Google App Engine is a step towards addressing that issue.


Filed under Application Mgmt, Automation, Cloud Computing, DevOps, Everything, Google, Google App Engine, Utility computing

Cloud management is to traditional IT management what spreadsheets are to calculators

It’s all in the title of the post. An elevator pitch short enough for a 1-story ride. A description for business people. People who don’t want to hear about models, virtualization, blueprints and devops. But people who also don’t want to be insulted with vague claims about “business/IT alignment” and “agility”.

The focus is on repeatability. Repeatability saves work and allows new approaches. I’ve found spreadsheets (and “super-spreadsheets”, i.e. more advanced BI tools) to be a good analogy for business people. Compared to analysts furiously operating calculators, spreadsheets save work and prevent errors. But beyond these cost savings, they allow you to do things you wouldn’t even try to do without them. It’s not just the same process, done faster and cheaper. It’s a more mature way of running your business.

Same with the “Cloud” style of IT management.


Filed under Application Mgmt, Automation, Big picture, Business, Cloud Computing, DevOps, Everything, IT Systems Mgmt, Manageability, Mgmt integration, Utility computing

The necessity of PaaS: Will Microsoft be the Singapore of Cloud Computing?

From ancient Mesopotamia to, more recently, Holland, Switzerland, Japan, Singapore and Korea, the success of many societies has been in part credited to their lack of natural resources. The theory being that it motivated them to rely on human capital, commerce and innovation rather than resource extraction. This approach eventually put them ahead of their better-endowed neighbors.

A similar dynamic may well propel Microsoft ahead in PaaS (Platform as a Service): IaaS with Windows is so painful that it may force Microsoft to focus on PaaS. The motivation is strong to “go up the stack” when the alternative is to cultivate the arid land of Windows-based IaaS.

I should disclose that I work for one of Microsoft’s main competitors, Oracle (though this blog only represents personal opinions), and that I am not an expert Windows system administrator. But I have enough experience to have seen some of the many reasons why Windows feels like a much less IaaS-friendly environment than Linux: e.g. the lack of SSH, the cumbersomeness of RDP, the constraints of the Windows license enforcement system, the Windows update mechanism, the immaturity of scripting, the difficulty of managing Windows from non-Windows machines (despite WS-Management), etc. For a simple illustration, go to EC2 and compare, between a Windows AMI and a Linux AMI, the steps (and time) needed to get from selecting an image to the point where you’re logged in and in control of a VM. And if you think that’s bad, things get even worse when we’re not just talking about a few long-lived Windows server instances in the Cloud but a highly dynamic environment in which all steps have to be automated and repeatable.

I am not saying that there aren’t ways around all this, just like it’s not impossible to grow grapes in Holland. It’s just usually not worth the effort. This recent post by RighScale illustrates both how hard it is but also that it is possible if you’re determined. The question is what benefits you get from Windows guests in IaaS and whether they justify the extra work. And also the additional license fee (while many of the issues are technical, others stem more from Microsoft’s refusal to acknowledge that the OS is a commodity). [Side note: this discussion is about Windows as a guest OS and not about the comparative virtues of Hyper-V, Xen-based hypervisors and VMWare.]

Under the DSI banner, Microsoft has been working for a while on improving the management/automation infrastructure for Windows, with tools like PowerShell (which I like a lot). These efforts pre-date the Cloud wave but definitely help Windows try to hold it own on the IaaS battleground. Still, it’s an uphill battle compared with Linux. So it makes perfect sense for Microsoft to move the battle to PaaS.

Just like commerce and innovation will, in the long term, bring more prosperity than focusing on mining and agriculture, PaaS will, in the long term, yield more benefits than IaaS. Even though it’s harder at first. That’s the good news for Microsoft.

On the other hand, lack of natural resources is not a guarantee of success either (as many poor desertic countries can testify) and Microsoft will have to fight to be successful in PaaS. But the work on Azure and many research efforts, like the “next-generation programming model for the cloud” (codename “Orleans”) that Mary Jo Foley revealed today, indicate that they are taking it very seriously. Their approach is not restricted by a VM-centric vision, which is often tempting for hypervisor and OS vendors. Microsoft’s move to PaaS is also facilitated by the fact that, while system administration and automation may not be a strength, development tools and application platforms are.

The forward-compatible Cloud will soon overshadow the backward-compatible Cloud and I expect Microsoft to play a role in it. They have to.


Filed under Application Mgmt, Automation, Azure, Cloud Computing, DevOps, Everything, IT Systems Mgmt, Linux, Manageability, Mgmt integration, Microsoft, Middleware, Oslo, PaaS, Research, Utility computing, WS-Management

Steve Ballmer gets Cloud

Steve Ballmer wants devops

Devops? What’s devops? See these articles:


Filed under Cloud Computing, DevOps, Everything, IT Systems Mgmt, Microsoft, People