Virtualization, Cloud, Infrastructure and all that stuff in-between

My ramblings on the stuff that holds it all together

Category Archives: Cloud Computing

CloudCamp London – March 12th


Registration is open for the next CloudCamp event in London on March 12th, I’ve attended once before and I like the format – a set of a ‘lightning talks’ around cloud topics, some networking and some detailed breakout sessions.

It’s an excellent and informal event to discuss cloud developments with your peers as well as find out what’s going on in the industry – best of all it’s free!

Information here and registration link here; if you’re UK/London based I’d recommend it, drop me a line via the comments if you are planning to attend or would like to meet up.

if you’re not UK-based; rest of the world events are here

Easy to Understand Overview of Amazon Web Services (AWS)


Brent Ozar has an excellent post here explaining how Amazon Web Services (AWS) can be used in a practical sense with a worked example.

It makes it easy to understand why you could use AWS if you’ve had trouble getting your head around what this could stuff is.

Amazon EC2 Web Console


I’ve been doing a bit of playing about with Amazon’s  EC2 cloud services recently, this is just a quick post with some screenshots of the new beta web console they have launched.

Up until now you had to control it via command line, or a firefox plug in – now Amazon have launched their own… seems very easy to use and understand – available online here


You can browse the list of pre-configured AMI’s (Amazon VM Images) and choose which ones you want to spin up.


I’m writing up some posts on using EC2 for quick ‘n’ dirty test and development environments, but I can see a lot of potential for this service to provide automated overspill capacity for applications using the automation API and some clever management tools.

What is the Cloud..?


Following on from some discussion on Scott Lowe’s blog around the lack of a clear definition of cloud computing, I offer this as my opinion… it’s just that; and I’d welcome comments. I’m an infrastructure chap by trade but my motto is there are no apps without infrastructure, and this cloud stuff is all about making things easier for developers to create useful stuff quickly and cheaply but it needs somewhere to run.

Sam Johnstone has also done some work on formalising this stack, but I offer the following up for discussion.

A cloud is just a pool of flexible/on-demand “resource” a way of abstracting the  underlying complexities of how things are executed or stored, provisioned etc.

This is analogous to the way the modern imagecomputer, OS and applications have developed over the last 20 years into multiple abstraction layers – meaning a developer no longer has to explicitly know how to control devices at a low level, for example; moving bits in and out of registers, reading/writing sectors to disks. They make API calls down a stack to BIOS, firmware, operating systems, drivers, code libraries (.DLL etc.) and more recently moving to web services at the top level interface.

Presently solution/infrastructure architects work with individual servers, roles and services on bits of dedicated hardware which are often bound to a specific location, ensuring that they architect the solution to deliver the required level of availability, serviceability etc.

I see “the cloud” as a way of providing the next level of abstraction – with an eventual goal of architects being able to design systems with no roles or services tied to specific servers/databases/hardware/datacentres/continents(!) where SOA-type applications and transactions are executed across one or more cloud platforms without having to have a detailed understanding of the underlying infrastructure.

In the interim the cloud can deliver a platform to quickly deploy and change infrastructure to deliver applications, right-sizing capacity based on actual usage rather than over-sizing done early into the development cycle of an application.

Fewer hard physical ties to the local infrastructure that supports application components, combined with adoption of virtualization of servers, networks etc. means that you can relocate services locally, nationally or globally through data and configuration migration rather than a traditional lift & shift of servers, switches, SAN’s racks etc. with the associated risk and downtime etc.

With standardisation or adoption of a common infrastructure architecture this could allow for a real market place to develop, where the customer can choose the most appropriate or cost-effective region or service provider to run their application(s) – either based on the cost of local power, comms, or response time, legal jurisdiction or SLA without being tied to a specific service provider or physical location.

For example; some of my previous posts on this sort of physical DC portability are here, if you combine this with a high level of virtualization and the cloud reference architecture you have a compelling solution for large infrastructures, Zimory also have an interesting proposition for brokering resources between multiple cloud providers

There are two fundamental things required to deliver this nirvana…

1) Flexible Infrastructure Architecture (do-able now with current tech )image

This is where I see my cloud reference architecture sitting, you could have multiple instances of this architecture split between on/off/3rd party premise providers – this provides a layer of abstraction between the physical hardware/networking/site world and an “application” or server instance (as it’s encapsulated in a VM – which is just persisted as a file on some storage.


2) Distributed Runtime/Services Layer (work starting now, needs development and standardisation)

To enable the cloud to really distribute applications (and thus computing power) across the Internet means you have to build a distributed or entirely democratic/autonomous controller mechanism (almost an OS for the cloud) which acts as a compiler, API, interpreter, Job Controller etc. to execute and manage applications (code/apps/scripts) that developers produce

This distributed runtime /services layer runs on server instances hosted on/in a cloud infrastructure (see item 1) that are managed by a service provider, to my mind there is no other way to achieve this you can’t easily write an app and just have it run across multiple locations without some kind of underlying abstraction layer taking care of the complexities of state, storage, parallelism etc. this is where Microsoft’s Azure, Amazon AWS & Google have API’s for things like databases , payment gateways, messaging, storage across their distributed infrastructures.

However all of them are doing it in a proprietary way – Azure/AWS provide their own API rather than a standardised set of services that true cloud apps can be written to and then moved between various cloud infrastructures or providers.


It’s important to note that the two are not mutually exclusive, clouds based on this reference architecture can still run traditional static one server/one app type services, even desktop/VDI but it also maintains server instances that run the actual distributed runtime/services layer for applications that are written to take advantage of it – there is a common underlying platform.

This model and standardisation helps address the concerns of most businesses when they start to talk about clouds, data ownership and security by giving them the opportunity to selectively adopt cloud technologies and transition workloads between on/off-premise clouds as needs dictate.

IBM BladeCenter S – Virtual DC in a Box


There is a detailed post here from IT2.0 on the IBM BladeCenter S, it shows how the chassis itself can contain disks and RAID’ed SAS controllers and works with vMotion/HA etc. and could potentially run up to 100 VM’s within 7U (no mention of power – which is more interesting to me).

If I read it correctly, that means you can integrate your blade servers and storage fabric within the same modular IBM chassis and it doesn’t require any external SAN storage or the use of one or more traditional server blades to “head-end” the storage (via iSCSI/NFS).

The pitch is around the SMB market, but I can see a wider application; if you are building internal cloud type infrastructures you might not get the budget to implement enterprise-type storage from day 1 as it requires a large up-front capital expenditure in FC/iSCSI switches, high performance disk arrays etc. particularly if you need something that will scale vertically to the large capacities or bandwidth that large VM estates require.

This type of approach could be ideal for horizontal scaling in reasonably priced “chunks” of capacity. If IBM (or a 3rd party vendor) were to introduce a storage replication bridge between the storage in two or more of these units then you could well be into a modular architecture for virtualization that would scale out to google-esque levels of world-domination in small, bite-sized chunks.

So far I’ve not seen anything similar from HP for the c-class blades – just storage blades that map 1:1 to an individual server blade via the PCI backplane.

Windows Azure under the hood


There is a an excellent video interview with Manuvir Das from the Azure team on the MSDN Channel 9 site here.

 )The interview is quite long, but I’ve tried to summarise it for infrastructure people/architects like me as follows;

Azure is an overall “OS” for the cloud, akin to VMWare and their VDC initiative but with a much richer re-usable services and applications framework layer.

In terms of describing the overall architecture diagram (below), Azure is sort of the”kernel for the cloud”, “Xbox for the cloud?” buy it in increments and (ab)use it – don’t worry about building the individual infrastructure components – you get all the tools in the box and the underlying infrastructure is abstracted so you don’t have to worry about it.

image image

The services layer Microsoft provide on top of Azure are as follows

Live Services Mesh (high level user/data sync – will run as app on Azure, doing some now) will be migrated to run on Azure over time

.net services (Zurich) high level services to enable rich scenarios like authentication, Federation, liveID, OpenID, Active Directory Federation Services etc.

SQL  – premium Database services in the cloud offering data warehousing, and I would assume massive scalability options – but I’m not sure how this would be implemented.

Sharepoint/Dynamics I understand are coming soon but would offer the same sort of functionality in the cloud.

It’s based around modified Windows with Dave Cutler’s involvement (no specifics offered yet) virtualized server instances are the base building blocks with an allocated and guaranteed amount of resource – 1×1.9GHz CPU, 2gb ram, 160gb disk) which is dedicated to your machine and not contended, which would mean MS are doing no over-subscription under the hood? that seems unlikely, and maybe wasteful to me; DRS anyone?

Dell have provided the underlying physical hardware hosted in Microsoft’s data centres with a customised server model, as noted here – and you can see a video tour inside one of the hosting data centres here from BBC news

There is an overall Fabric Controller which is essentially a resource manager, it continually monitors hosts, VMs, storage via agents and deploys/allocates/moves .net code packages around hosts.

to deploy your service to the Azure cloud;

You build your application as a code package (.net, others coming later)

You build a service model, this describes the number, type of hosts, dependencies etc.

The Azure storage layer a distributed, flat table-based storage system with a a distributed lock manager and keeps 3 copies of data for availability – it’s not SQL based (interesting) uses a REST API and is more akin to a file system so sounds like it’s been written from the ground up.

Interestingly it seems that the storage layer is deployed as a service on Azure itself and is controlled by the fabric manager, parts of the current live mesh services are using it now in production.

Interestingly Manuvir describes your service as containing routers, load balancers as well as traditional services so it sounds like they may have either built a complex provisioning framework for physical devices, or have implemented virtualized versions of such devices (Cisco Nexus type devices implemented as VM’s maybe?)

Azure can maintain staging and production platforms within the cloud, you can swap between production/stage etc. with an API command that re-points DNS.

There is a concept of an upgrade domain; where VMs are taken out of service for updates/deployments etc. – your service description I assume describes what are key dependencies and it works out the least-impact sequence?

No automatic paralellism, you can’t just issue a job and have it execute in a distributed fashion using all the Azure resources without being designed/built as such, which I think Amazon offer (but I may be wrong, as that does sound like something v.complicated to do)

Azure strategy for scale out is the traditional MS one, make the most use of individual resource allocation for your VMs (see above), scale out multiple independent instances with a shared nothing architecture

Azure is a programmable API, it’s not an end-user product, it’s a platform for developers to build services on.

There is no absolute requirement for will provide PHP/RoR/Python facilities over time and .net and visual studio integration out of the box – but can use other developer tools too.

A “Developer fabric” is available – it can run on a desktop, it mocks up the whole Azure platform on your desktop and behaves the same way so developers can understand how it works and debug applications on their desktops before pushing out to the cloud – this is an important shiny for Microsoft, as it’s a simple and quick way to get developers hands-on with understanding how to use Azure.

The cool part is that you can export your service model and code packages directly to Azure from your developer tool, akin to a compile and public option for the cloud. it’s part of SDK which can be downloaded here.

You can debug service copies locally using the SDK and developer fabric, no debugging in the cloud {yet} but provides an API to get logs and are working on an end-end transaction tracing API

Microsoft have made references to making Azure on-premise as well as in Microsoft’s own data centres in the same way that VMWare have with the VDC-OS stuff… but I would think that’s going to need some more details on what the Azure OS is to understand how that would be feasible.

As I concluded in an earlier blog post here, Microsoft could be poised to clean up here if they execute quickly and well – they have the most comprehensive offering for the corporate space due to having a very rich applications/services layer that is directly aligned to the desktop & application technology choices of the bigger customers (.net), they just need to solve the trust in the cloud issue first; and the on-premise piece of the puzzle is key to this… Maybe a server version of Windows 7 or MiniWin or Singularity is the enabler for this?

Microsoft Moves into the Clouds


As you’ve probably seen and I mentioned here earlier Microsoft are laying out their vision for Microsoft-centric cloud computing this week at their Professional Developers Conference.

If you’re short of time to understand this there is a good quick overview here, here and here, apologies for lack of posting recently which has been due to the awful cold I’ve had and a backlog of “real” work to deal with.

I’m attending Microsoft TechEd next week in Barcelona,  so I’m hoping to get more real information about how this will work in the real world and I’ll be blogging as much of that content as possible.

Not sure I can live up to the level of posts Scott managed earlier in the year at TechEd US but I’ll try 🙂

Cloud is the new Mesh 🙂

Cloud Computing Stack – formalised


Sam Johnston has an interesting article here where he’s attempted to formalise the cloud computing stack into something like the OSI model and has an associated wiki for contributions.

I’ve not come across Sam’s blog before before but a quick review shows that Sam has some interesting architectural discussions around cloud computing – check it out.

Cloud Wars: VMWare vs Microsoft vs Google vs Amazon Clouds


A short time ago in a data centre, far far away…..

All the big players are setting out their cloud pitches, Microsoft are set to make some big announcements at their Professional Developer Conference at the end of October and VMWare made their VDC-OS announcements at VMWorld a couple of weeks ago, Google have had their App Engine in beta for a while and Amazon AWS is pretty well established.

With this post I hope to give a quick overview of each, I’ll freely admit I’m more knowledgeable on the VMWare/Microsoft offerings… and I stand to be corrected on any assumptions I’ve made on Google/AWS based on my web reading.

So, What’s the difference between them…?

VMWare vCloud – infrastructure led play

VMWare come from the infrastructure space, to-date they have dominated the x86 virtualization market, they have some key strategic partnerships with storage and network vendors to deliver integrated solutions.

The VMWare VDC-OS pitch is about providing a flexible underlying architecture through servers, network and storage virtualisation. why? because making everything ‘virtual’ makes for quick reconfiguration – reallocating resource from one service to another is a configuration/allocation change rather than requiring an engineer visit (see my other post on this for more info)

because VMWare’s pitch is infrastructure led it has a significant practical advantage in that it’s essentially technology agnostic (as long as it’s x86 based) you, or a service provider have the ability to build and maintain an automated birth–>death bare ‘virtual metal’ provisioning and lifecycle system for application servers/services as there is no longer a tight dependency for everything on physical hardware, cabling etc

There is no one size fits all product in this space so a bespoke solution based around a standard framework tool like Tivoli, SMS, etc. is typically required depending on organisational/service requirements.

No re-development is necessarily required to move your applications into a vCloud (hosted or internal) you just move your VMWare virtual machines to a different underlying VDC-OS infrastructure, or you use P2V, X2V tools like Platespin to migrate to a VDC-OS infrastructure.

In terms of limitations – apps can’t necessarily scale horizontally (yet) as they are constrained by their traditional server based roots. The ability to add a 2nd node doesn’t necessarily make your app scale – there are all kinds of issues around state, concurrency etc. that the application framework needs to manage.

VMWare are building frameworks to build scale-out provisioning tools – but this would only work for certain types of applications and is currently reactive unless you build some intelligence into the provisioning system.

Scott Lowe has a good round-up of VDC-OS information here & VMWare’s official page is online here

Google AppEngine– pure app framework play

An application framework for you to develop your apps within – it provides a vastly parallel application and storage framework – excellent for developing large applications (i.e Google’s bread & butter)

Disadvantage is it’s a complete redevelopment of you applications into Google compatible code, services & frameworks. You are tied into Google services – you can’t (as I understand it) take your developed applications elsewhere without significant re-development/porting.

The Google AppEngine blog is here

Microsoft Cloud Services Hosted Application stack & Infrastructure play

An interesting offering, they will technically have the ability to host .net applications from a shared hosting service, as well as integrating future versions of their traditional and well established office/productivity applications into their cloud platform; almost offering the subscription based/Software+Services model they’ve been mooting for a long time.

Given Microsoft’s market current dominance, they are very well positioned to make this successful as large shops will be able to modify existing internal .net services and applications to leverage portions of their cloud offering.

With the future developments of Hyper-V Microsoft will be well positioned to offer an infrastructure driven equivalent of VMWare’s VDC-OS proposition to service and support migration from existing dedicated Windows and Linux servers to an internal or externally hosted cloud type platform.

David Chou at Microsoft has a good post on Microsoft and clouds here

Amazon Web Services – established app framework with canned virtualization

the AWS platform provides a range of the same sort of functionality as Google AppEngine with SimpleDB,  SQS and S3 but with the recently announced ability to run Windows within their EC2 cloud makes for an interesting offering with the existing ability to pick & choose from Linux based virtual machine instances.

I believe EC2 makes heavy use of Xen under the hood; which I assume is how they are going to be delivering the Windows based services, EC2 also allows you to choose from a number of standard Linux virtual machine offerings (Amazon Machine Image, AMI).

This is an interesting offering, allowing you to develop your applications into their framework and possibly port or build your Linux/Windows application services into their managed EC2 service.

Same caveat applies though, your apps and virtual machines could be tied to the AWS framework – so you loose your portability without significant re-engineering. on the flip-side they do seem to have the best defined commercial and support models and have been well established for a while with the S3 service.

Amazon’s AWS blog is available here


Microsoft & VMWare are best positioned to pick up businesses from the corporate’s who will likely have a large existing investment in code and infrastructure but are looking to take advantage of reduced cost and complexity by hosting portions of their app/infrastructure with a service-provider.

Microsoft & VMWare offerings easily lend themselves to this internal/external cloud architecture as you can build your own internal cloud using their off-the-shelf technology, something that isn’t possible with AWS or Google. This is likely to be the preferred model for most large businesses who need to retain ownership of data and certain systems for legal/compliance reasons.

leveraging virtualization and commercial X2V or X2X conversion tools will make transition between internal and external clouds simple and quick – which gives organisations a lot of flexibility to operate their systems in the most cost/load-effective manner as well as retain detailed control of the application/server infrastructure but freed up from the day-day hardware/capacity management roles.

AWS/Google are ideal for Web 2.0 ,start-ups and the SME sector where there is typically no existing or large code-base investment that would need to be leveraged. For a greenfield implementation these services offer low start-up cost and simple development tools to build applications that would be complicated & expensive to build if you had to worry about and develop supporting infrastructure without significant up-front capital backing.

AWS/Google are also great for people wanting to build applications that need to scale to lots of users, but without a deep understanding of the required underlying infrastructure, whilst this is appealing to corporate’s  I think the cost of porting and data ownership/risk issues will be a blocker for a significant amount of time.

Google Apps are a good entry point for the SME/start-up sector and startups, and could well draw people into building AppEngine services as the business grows in size and complexity, so we may see a drift towards this over time. Microsoft have a competing model and could leverage their established brand to win over customers if they can make the entry point free/cheap and cross-platform compatible, lots of those SME/start-ups are using Mac’s or Netbooks for example.

VMWare vCloud


The news is out, VMWare are building some very interesting technology frameworks to enable you to build your own cloud architectures, but also to be able to transition VMs from your environment to a service provider offering a hosted service and mix & match as required.

All very clever stuff, I’ve been working with VMWare on this for the last couple of weeks and it all links in nicely to an article I wrote a couple of months back on how VMWare can deliver this type of infrastructure now. nice to see it’s being “productized” and being explained as a concept to the world, I see Scott’s point and I also hope that people do realise it’s the underlying virtualization tech they are focusing on not some overarching end-end GoogleOS that does everything – although the clever bit is building management frameworks to allow another vendor to do this type of integration.

Read the vCloud page here and overview of the virtual data centre stuff here