For the last concentrate of years the It industry has been getting excited and energised about Cloud. Large It companies and consultancies have spent, and are spending, billions of dollars, pounds and yen investing in Cloud technologies. So, what's uh, the deal?
While Cloud is generating lot more heat than light it is, nonetheless, giving us all something to think about and something to sell our customers. In some respects Cloud isn't new, in other respects it's ground-breaking and will make an undeniable change in the way that company provides users with applications and services.
Beyond that, and it is already happening, users will at last be able to contribute their own Processing, Memory, warehouse and Network (Pmsn) resources at one level, and at other levels receive applications and services anywhere, anytime, using (almost) any movable technology. In short, Cloud can liberate users, make remote working more feasible, ease It supervision and move a company from CapEx to more of an OpEx situation. If a company is receiving applications and services from Cloud, depending on the type of Cloud, it may not need a data centre or server-room any more. All it will require is to cover the costs of the applications and services that it uses. Some in It may realize this as a threat, others as a liberation.
So, what is Cloud?
To understand Cloud you need to understand the base technologies, theory and drivers that reserve it and have provided a lot of the impetus to design it.
Virtualisation
For the last decade the industry has been super-busy consolidating data centres and server-rooms from racks of tin boxes to less racks of fewer tin boxes. At the same time the amount of applications able to exist in this new and smaller footprint has been increasing.
Virtualisation; why do it?
Servers hosting a single application have utilisation levels of around 15%. That means that the server is ticking over and extremely under-utilised. The cost of data centres full of servers running at 15% is a financial nightmare. Server utilisation of 15% can't return anything on the first speculation for many years, if ever. Servers have a lifecycle of about 3 years and a depreciation of about 50% out of the box. After three years, the servers are worth anything in corporate terms.
Today we have refined tool-sets that enable us to virtualise pretty much any server and in doing that we can originate clusters of virtualised servers that are able to host many applications and services. This has brought many benefits. Higher densities of Application servers hosted on fewer reserved supply servers enables the data centre to deliver more applications and services.
It's Cooler, It's Greener
Besides the discount of private hardware systems straight through expeditious use of virtualisation, data centre designers and hardware manufacturers have introduced other methods and technologies to sell out the amount of power required to cool the systems and the data centre halls. These days servers and other hardware systems have directional air-flow. A server may have front-to-back or back-to-front directional fans that drive the heated air into a single direction that suits the air-flow design of the data centre. Air-flow is the new science in the It industry. It is becoming common to have a hot-isle and a cold-isle matrix across the data centre hall. Having systems that can riposte and share in that design can produce needful savings in power requirements. The selection of where to build a data centre is also becoming more important.
There is also the Green agenda. companies want to be seen to be thoughprovoking with this new and beloved movement. The amount of power needed to run large data centres is in the Megawatt region and hardly Green. Large data centres will all the time require high levels of power. Hardware manufacturers are attempting to bring down the power requirements of their products and data centre designers are production a big endeavor to make more use of (natural) air-flow. Taken together these efforts are production a difference. If being Green is going to save money, then it's a good thing.
Downsides
High utilisation of hardware introduces higher levels of failure caused, in the most part, by heat. In the case of the 121 ratio, the server is idling, cool and under-utilised and costing more money than needful (in terms of Roi) but, will contribute a long lifecycle. In the case of virtualisation, producing higher levels of utilisation per Host will originate a lot more heat. Heat damages components (degradation over time) and shortens Mttf (Mean Time To Failure) which affects Tco (Total Cost of rights = the lowest line) and Roi (Return on Investment). It also raises the cooling requirement which in turn increases power consumption. When immense Parallel Processing is required, and this is very much a cloud technology, cooling and power will step up a notch. immense Parallel Processing can use tens of thousands of servers/Vms, large warehouse environments along with complicated and large networks. This level of processing will growth energy requirements. Basically, you can't have it both ways.
Another downside to virtualisation is Vm density. Fantasize 500 hardware servers, each hosting 192 Vms. That's 96,000 Virtual Machines. The median amount of Vms per Host server is little by the amount of vendor-recommended Vms per Cpu. If a server has 16 Cpus (Cores) you could originate practically 12 Vms per Core (this is entirely dependent on what the Vm is going to be used for). Therefore it's a easy piece of arithmetic, 500 X 192 = 96,000 Virtual Machines. Architects take all this into list when designing large virtualisation infrastructures and make sure that Sprawl is kept strictly under control. However, the danger exists.
Virtualisation; The basics of how to do it
Take a single computer, a server, and install software that enables the abstraction of the basic hardware resources: Processing, Memory, warehouse and Networking. Once you've configured this virtualisation-capable software, you can use it to fool assorted operating systems into reasoning that they are being installed into a customary environment that they recognise. This is achieved by the virtualisation software that (should) comprise all the needful drivers used by the operating theory to talk to the hardware.
At the lowest of the virtualisation stack is the Hardware Host. install the hypervisor on this machine. The hypervisor abstracts the hardware resources and delivers them to the virtual machines (Vms). On the Vm install the appropriate operating system. Now install the application/s. A single hardware Host can reserve a amount of Guest operating systems, or Virtual Machines, dependent on the purpose of the Vm and the amount of processing cores in the Host. Each hypervisor vendor has its own permutation of Vms to Cores ratio but, it is also needful to understand exactly what the Vms are going to reserve to be able to surmise the provisioning of the Vms. Sizing/Provisioning virtual infrastructures is the new black-art in It and there are many tools and utilities to help carry out that crucial and needful task. Despite all the helpful gadgets, part of the art of sizing is still down to informed guesswork and experience. This means that the machines haven't taken over yet!
Hypervisor
The hypervisor can be installed in two formats:
1. install an operating theory that has within it some code that constitutes a hypervisor. Once the operating theory is installed, click a concentrate of boxes and reboot the operating theory to get underway the hypervisor. This is called Host Virtualisation because there is a Host operating system, such as Windows 2008 or a Linux distribution, as the foundation and controller of the hypervisor. The base operating theory is installed in the usual way, directly onto the hardware/server. A modification is made and the theory is rebooted. Next time it loads it will offer the hypervisor configuration as a bootable choice
2. install a hypervisor directly onto the hardware/server. Once installed, the hypervisor will abstract the hardware resources and make them available to many Guest operating systems via a Virtual machine. Vmware's Esxi and Xen are this type of hypervisor (on-the-metal hypervisor)
The two most beloved hypervisors are Vmware Esxi and Microsoft's Hyper-V. Esxi is a stand-alone hypervisor that is installed directly onto the hardware. Hyper-V is part of the Windows 2008 operating system. Windows 2008 must be installed first to be able to use the hypervisor within the operating system. Hyper-V is an thoughprovoking proposition but, it does not sell out the footprint to the size of Esxi (Hyper-V is about 2Gb on the disk and Esxi is about 70Mb on the disk), and it does not sell out the overhead to a level as low Esxi.
To carry on virtual environments requires other applications. Vmware offers vCenter Server and Microsoft offers theory town Virtual engine Manager. There are a range of third-party tools available to improve these activities.
Which hypervisor to use?
The selection of which virtualisation software to use should be based on informed decisions. Sizing the Hosts, provisioning the Vms, choosing the reserve toolsets and models, and a whole raft of other questions need to be answered to make sure that money and time is spent effectively and what is implemented works and doesn't need immense change for a concentrate of years (wouldn't that be nice?).
What is Cloud Computing?
Look around the Web and there are myriad definitions. Here's mine. "Cloud Computing is billable, virtualised, elastic services"
Cloud is a metaphor for the methods that enable users to passage applications and services using the Internet and the Web.
Everything from the passage layer to the lowest of the stack is placed in the data centre and never leaves it.
Within this stack are many other applications and services that enable monitoring of the Processing, Memory, warehouse and Network which can then be used by chargeback applications to contribute metering and billing.
Cloud Computing Models
The Deployment Model and the Delivery Model.
Deployment Model
- inexpressive Cloud
- group Cloud
- community Cloud
- Hybrid Cloud
Private Cloud Deployment Model
For most businesses the inexpressive Cloud Deployment Model will be the Model of choice. It provides a high level of security and for those companies and organisation that have to take compliancy and data security laws into consideration inexpressive Cloud will be the only appropriate Deployment Model.
Note: There are companies (providers) selling managed hosting as Cloud. They rely on the hype and blurring about what Cloud truly is. Check exactly what is on offer or it may turn out that the product is not Cloud and cannot offer the attributes of Cloud.
Public Cloud Deployment Model
Amazon Ec2 is a good example of the group Cloud Deployment Model. Users in this case are, by and large, the group although more and more businesses are looking group Cloud a useful expanding to their current delivery models.
Small company can take benefit of the group Cloud low costs, particularly where security is not an issue. Even large enterprises, organisations and government institutions can find advantages in utilising group Cloud. It will depend on legal and data security requirements.
Community Cloud Deployment Model
This model is created by users allowing their personal computers to be used as resources in a P2P (Point-to-Point) network. Given that contemporary Pcs/Workstations have multiprocessors, a good chunk of Ram and large Sata warehouse disks, it is sensible to utilise these resources to enable a community of users each contributing Pmsn and sharing the applications and services made available. Large numbers of Pcs and, possibly, servers can be connected into a single subnet. Users are the contributors and consumers of compute resources, applications and services via the community Cloud.
The benefit of the community Cloud is that it's not tied to a vendor and not field to the company case of a vendor. That means the community can set its own costs and prices. It can be a completely free service and run as a co-operative.
Security may not be as needful but, the fact that each user has passage at a low level might introduce the risk of security breaches, and ensue bad blood among the group.
While user communities can benefit from vendor detachment it isn't needful that vendors are excluded. Vendor/providers can also deliver community Cloud, at a cost.
Large companies that may share certain needs can also share using community Cloud. community Cloud can be useful where a major disaster has occurred and a company has lost services. If that company is part of a community Cloud (car manufacturers, oil companies etc.) those services may be available from other sources within that Cloud.
Hybrid Cloud Deployment Model
The Hybrid Cloud is used where it is useful to have passage to the group Cloud while maintaining certain security restrictions on users and data within a inexpressive Cloud. For instance, a company has a data centre from which it delivers inexpressive Cloud services to its staff but, it needs to have some formula of delivering ubiquitous services to the group or to users exterior its own network. The Hybrid Cloud can contribute this kind of environment. companies using Hybrid Cloud services can take benefit of the immense scalability of the group Cloud delivered from group Cloud providers, while still maintaining control and security over needful data and compliancy requirements.
Federated Clouds
While this is not a Cloud deployment or delivery model per se, it is going to become an important part of Cloud Computing services in the future.
As the Cloud market increases and enlarges across the world, the diversity of provision is going to become more and more difficult to carry on or even clarify. Many Cloud providers will be hostile to each other and may not be keen to share across their Clouds. company and users will want to be able to diversify and multiply their choices of Cloud delivery and provision. Having many Clouds increases the availability of applications and services.
A company may find that it is a good idea to utilise many Cloud providers to enable data to be used in differing Clouds for differing groups. The problem is how to control/manage this many headed delivery model? It can take control back by acting as the central office clearing house for the many Clouds. Workloads may require different levels of security, compliance, execution and Slas across the whole company. Being able to use many Clouds to fulfil each requirement for each workload is a certain benefit over the one-size-fits-all principle that a single Cloud victualer brings to the table. Federated Cloud also answers the request of How do I avoid vendor lock-in? However, many Clouds require rigorous supervision and that's where the Federated Cloud comes in.
So, what is stopping this happening? Mostly it's about the differences between operating systems and platforms. The other surmise is that thoughprovoking a Vm can be difficult when that Vm is 100Gbs. If you Fantasize thousands of those being moved around simultaneously you can see why true Cloud federation is not yet with us, although some companies are out there trying to make it happen. Right now you can't move a Vm out of Ec2 into Azure or OpenStack.
True federation is where disparate Clouds can be managed together seamlessly and where Vms can be moved between Clouds.
Abstraction
The physical layer resources were abstracted by the hypervisor to contribute an environment for the Guest operating systems via the Vms. This layer of abstraction is managed by the appropriate vendor virtualisation supervision tools (in the case of Vmware its vSphere vCenter Server and its Apis). The Cloud supervision Layer (vCloud Director in the case of Vmware) is an abstraction of the Virtualisation Layer. It has taken the Vms, applications and services (and users) and organised them into groups. It can then make them available to users.
Using the abstracted virtual layer it is potential to deliver IaaS, PaaS and SaaS to Private, Public, community and Hybrid Cloud users.
Cloud Delivery Models
IaaS-Infrastructure as a service (Lower Layer)
When a customer buys IaaS it will receive the whole compute infrastructure together with Power/Cooling, Host (hardware) servers, storage, networking and Vms (supplied as servers). It is the customers responsibility to install the operating systems, carry on the infrastructure and to patch and modernize as necessary. These terms can vary depending on the vendor/provider and the private ageement details.
PaaS-Platform as a service (Middle Layer)
PaaS delivers a single platform or platforms to a customer. This might be a Linux or Windows environment. All things is provided together with the operating systems ready for software developers (the main users of PaaS) to originate and test their products. Billing can be based on reserved supply usage over time. There are a amount of billing models to suit assorted requirements.
SaaS-Software as a service (Top Layer)
SaaS delivers a unblemished computing environment along with applications ready for user access. This is the appropriate offer in the group Cloud. Examples of applications would be Microsoft's Office 365. In this environment the customer has no responsibility to carry on the infrastructure.
Cloud Metering & Billing
Metering
Billing is derived from the chargeback information (Metering) gleaned from the infrastructure. Depending on the service ordered the billing will comprise the resources outlined below.
Billable reserved supply Options: (Courtesy Cisco)
Virtual machine: Cpu, Memory, warehouse capacity, Disk and network I/O
Server blade Options will vary by type and size of the hardware
Network services: Load balancer, Firewall, Virtual router
Security services: Isolation level, compliancy level
Service-level agreements (Slas): Best endeavor (Bronze), High availability (Silver), Fault tolerant (Gold)
Data services: Data encryption, Data compression, Backups, Data availability and redundancy
Wan services: Vpn connectivity, Wan optimisation
Billing
Pay-as-you-Go: easy payment based on billing from the provider. Commonly customers are billed for Cpu and Ram usage only when the server is truly running. Billing can be Pre-Paid, or Pay-as-you-Go. For servers (Vms) that are in a non-running state (stopped), the customer only pays for the warehouse that server is using. If a server is deleted, there are no additional charges. Pay-as-you-Go can be a aggregate of a range of information billed as a single item. For instance, Network usage can be charged for each hour that a network or networks are deployed. Outbound and Inbound Bandwidth can be charged; Ntt America charges only for outbound traffic leaving a customer network or Cloud Files warehouse environment, whereas inbound traffic may be billed, or not. It all comes down to what the victualer offers and what you have chosen to buy.
Pre-Allocated
Some current cloud models use pre-allocation, such as a server instance or a compute slice,as the basis for pricing. Here, the reserved supply that a customer is billed for has to be allocated first, allowing for predictability and pre-approval of the expenditure. However, the term instance can be defined in different ways. If the instance is plainly a chunk of processing time on a server equal to 750 hours, that equates to a full month. If the size of the instance is connected to a definite hardware configuration, the billing appears to be based on hours of processing, but in fact reflects passage to a definite server configuration for a month. As such, this pricing buildings doesn't differ significantly from original server hosting.
Reservation or Reserved
Amazon, for instance, uses the term Reserved Instance Billing. This refers to usage of Vms over time. The customer purchases a amount of Reserved Instances in advance. There are three levels of Reserved Instance billing, Light, Medium and Heavy Reserved Instances. If the customer increases usage of instance above the set rate Amazon will charge at the higher rate. That's not an exact report but, it's close enough.
Cloud billing is not a easy and easy as vendors would like to have us believe. Read determined the conditions and try to stick rigidly to the prescribed usage levels or the bill could come as a shock.
The hereafter of Cloud
Some say Cloud has no hereafter and that it's plainly an additional one trend. Larry Ellison (of Oracle) made a statement a few years ago that Cloud was an aberration or fashion generated by an industry that was looking desperately for something, anything, new to sell (paraphrased). Others say that Cloud is the hereafter of It and Is delivery. The latter seem to be correct. It's clear that Cloud is the topical field on the lips of all It geeks and gurus. It's also true that the group at large is becoming Cloud-savvy and, due to the dominance of movable computing, the group and company will continue to request on-tap utility-computing, (John McCarthy, speaking at the Mit Centennial in 1961 forecast that computing would become a group utility), via desktops, laptops, netbooks, iPads, iPhones, Smartphones and gadgets yet to be invented. Cloud can contribute that ubiquitous, elastic and billable utility.
robb@emailinx.com
2012
