My ramblings on the stuff that holds it all together
Virtualization – the key to delivering "cloud based architecture" NOW.
June 23, 2008Posted by on
There is a lot of talk about delivering cloud or elastic computing platforms, a lot of CxO’s are taking this all in and nodding enthusiastically, they can see the benefits.. so make it happen!….yesterday.
You can build your own cloud, and be choosy about what you give to others. building your own cloud makes a lot of sense, it’s not always cheap but its the kind of thing you can scale up (or down..) with a bit of up-front investment, in this article I’ll look at some of the practical; and more infrastructure focused ways in which you can do so.
Your “cloud platform” is essentially an internal shared services system where you can actually and practically implement a “platform” team that operates and capacity plans for the cloud platform; they manage it’s availability and maintenance day-day and expansion/contraction.
You then have a number of “service/application” teams that subscribe to services provided by your cloud platform team… they are essentially developers/support teams that manage individual applications or services (for example payroll or SAP, web sites etc.), business units and stakeholders etc.
Using the technology we discuss here you can delegate control to them over most aspects of the service they maintian – full access to app servers etc. and an interface (human or automated) to raise issues with the platform team or log change requests.
I’ve seen many attempts to implement this in the physical/old world and it just ends in tears as it builds a high level of expectation that the server/infrastructure team must be able to respond very quickly to the end-”customer” the customer/supplier relationship is very different… regardless of what OLA/SLA you put in place.
However the reality of traditional infrastructure is that the platform team can’t usually react as quick as the service/application teams need/want/expect because they need to have an engineer on-site, wait for an order and a delivery, a network provisioning order etc. etc (although banks do seems to have this down quite well, it’s still a delay.. and time is money, etc.)
Virtualization and some of the technology we discuss here enable the platform team to keep one step ahead of the service/application teams by allowing them to do proper capacity planning and maintain a pragmatic headroom of capacity and make their lives easier by consolidating the physical estate they manage. This extra headroom capacity can be quickly back-filled when it’s taken up by adopting a modular hardware architecture to keep ahead of the next requirement.
Traditional infrastructure = OS/App Installations
- 1 server per ‘workload’
- Silo’d servers for support
- Individually underused on average = overall wastage
- No easy way to move workload about
- Change = slow, person in DC, unplug, uninstall, move reinstall etc.
- HP/Dell/Sun Rack Mount Servers
- Cat 6 Cables, Racks and structured cabling
The ideal is to have an OS/app stack that can have workloads moved from host A to host B; this is a nice idea but there are a whole heap of dependencies with the typlical applications of today (IIS/apache + scripts, RoR, SQL DB, custom .net applications). Most big/important line of business apps are monolithic and today make this hard. Ever tried to move a SQL installation from OLD-SERVER-A to SHINY-NEW-SERVER-B? exactly. *NIX better at this, but not that much better.. downtime required or complicated fail over.
This can all be done today, virtualization is the key to doing it – makes it easy to move a workload from a to b we don’t care about the OS/hardware integration – we standardise/abstract/virtualize it and that allows us to quickly move it – it’s just a file and a bunch of configuration information in a text file… no obscure array controller firmware to extract data from or outdated NIC/video drivers to worry about.
Combine this with server (blade) hardware, modern VLAN/L3 switches with trunked connections, and virtualised firewalls then you have a very compelling solution that is not only quick to change, but makes more efficient use of the hardware you’ve purchased… so each KW/hr you consume brings more return, not less as you expand.
Now, move this forward and change the hardware for something much more commodity/standardised
Requirement: Fast, Scalable shared storage, filexible allocation of disk space and ability to de-duplicate data, reduce overhead etc, thin provisioning.
Solution: SAN Storage, EMC Clariion, HP-EVA, Sun StorageTek, iSCSI for lower requirements, or storage over single Ethernet fabric – NetApp/Equalogic
Requirement: Requirement Common chassis and server modules for quick, easy rip and replace and efficient power/cooling.
Solution: HP/Sun/Dell Blades
Requirement: quick change of network configurations, cross connects, increase & decrease bandwidth
Solution: Cisco switching, trunked interconnects, 10Gb/bonded 1GbE, VLAN isolation, quick change enabled as beyond initial installation there are fewer requirements to send an engineer to plug something in or move it, Checkpoint VSX firewalls to allow delegated firewall configurations or to allow multiple autonomous business units (or customers) to operate from a shared, high bandwidth platform.
Requirement: Ability to load balance and consolidate individual server workloads
Solution: VMWare Infrastructure 3 + management toolset (SCOM, Virtual Centre, Custom you-specific integrations using API/SDK etc.)
Requirement: Delegated control of systems to allow autonomy to teams, but within a controlled/auditable framework
Solution: Normal OS/app security delegation, Active Directory, NIS etc. Virtual Center, Checkpoint VSX, custom change request workflow and automation systems which are plugged into platform API/SDK’s etc.
the following diagram is my reference architecture for how I see these cloud platforms hanging together
As ever more services move into the “cloud” or the “mesh” then integrating them becomes simpler, you have less of a focus on the platform that runs it – and just build what you need to operate your business etc.
In future maybe you’ll be able to use the public cloud services like Amazon AWS to integrate with your own internal cloud, allowing you to retain the important internal company data but take advantage of external, utility computing as required, on demand etc.
I don’t think we’ll ever get to.. (or want) to be 100% in a public cloud, but this private/internal cloud allows an organisation to retain it’s own internal agility and data ownership.
I hope this post has demonstrated that whilst, architecturally “cloud” computing sounds a bit out-there, you can practically implement it now by adopting this approach for the underlying infrastructure for your current application landscape.