Technical Architecture

Microsoft’s UK Architecture Resources

Dave Oliver — Sat, 09 May 2009 15:17:44 GMT

To Microsoft’s credit their Architecture resources are much improving. The excellent free Architecture Journal and the MSDN Architecture Centre have been going for sometime but I noticed recently that there is a new UK centric Architecture Portal written by the UK DPE Architect Team with the new free monthly Arc Magazine.

The first editions of the Arc Magazine tackle the highly logical new buzz ‘Software + Services’ with links to the Microsoft Strategy Software + Services Home Page. I will talk about this is greater depth in later posts.

It is clear that they are keen to hear what we think so they have a Polls Portal (written using Zoho Polls I notice)

One other really cool link I found off the page was a link to recordings of all of the Architecture stream PDC sessions from last year so another piece of Architecture resource gold!

Microsoft in recent years certainly has gone from ‘zero to hero’ in terms of Architecture my only real criticisms are that they are to software development centric still and need to get in touch more with their inner IT Pro.

Also Architecture is a practice of balancing Software Yin, and Hardware Yang, so it is also important to talk about specification and configuration of hardware and networking in a bit more depth than just the current light touch. This could be an opportunity to see more joint articles with key hardware partner such as Dell & HP as Architects also need to know about what is happening in this fast paced side of the industry and how it effects software.

All in all a good start and certainly somewhere I will regularly visit and another two RSS feed’s (Features RSS Feed and News RSS feed) to subscribe to.

They are also keen to hear what you think so email your comments to ukarch@microsoft.com.

Technorati Tags: Microsoft,Architecture,Software + Services

What is all the fuss about Cloud Computing?

Dave Oliver — Wed, 08 Apr 2009 01:36:08 GMT

Cloud computing is the buzzword of the moment . It seems that applying the "cloud" label is a real desire for a lot of people out there in the marketplace. This of course leads to the arguments about whether the "cloud" label is appropriate or just marketing spin.

Why on earth is Cloud Computing so appealing?

I think there are a lot of factors. I'll outline a few of the main ones below …

Trendy
To a certain extent delivering a cloud solution suggests that organisations are on the cutting edge of technology - and this hints that there is something worthwhile in the technology being delivered. Also the important important human-factor of the innate desire to follow fashion and trends.
Cost effective
One of the big claims of Cloud Computing is that it delivers the lowest cost of hardware possible. Not only are the servers uniform, they are designed in a way to scale broadly so that even large applications can be hosted without requiring special hardware. This is one of the reasons why Cloud Computing is sometimes called "Utility computing". That is, hardware that functions like a utility... it's just there.
High availability
Overall most cloud computing environments are designed to provide high availability - if one physical machine goes down, there is always another one to seamlessly pop in and pick up the load. As software-based services are being delivered via the cloud, this is a critical component to be concerned with. If you want to have 50,000,000 users, they have an expectation that their service will be there when they want it. Cloud computing generally helps manage this risk.
Operational Simplicity
It's a great relief to have someone else manage the infrastructure. Putting the hardware together is one thing, being stuck operating it forever is quite another. People who operate cloud computing farms generally have gotten the process down to a very efficient science. Of course this also helps out the cost profile, but it also means that the management is efficient. It is a big deal.
Financial Scalability
Cloud computing is often a "pay as you go" kind of deal. This minimizes the up-front costs and allows a small ISV to get into the game with a quality infrastructure that otherwise they might not be able to afford. When you pay by the CPU minute, then you can really trim down your costs to just what you are actually consuming. When it comes to matching costs to revenues (which you do hope to have), getting the costs down to actual with no extra is a nice deal.

Cons

It’s pretty clear that Cloud Computing as a concept has many problems to iron out before it can be considered a viable option by the Enterprise; the two mains ones are confidence and standards maturity.

The confidence problem centres around security concerns and belief. Questions such as, Who else can read my data when it is submitted to the Cloud? Are the claims of the benefits of Cloud computing really all to good to be true, what’s the catch?

It is also clear that the main players in Cloud Computing cannot agree on whether there should be standards right now or not. My feeling is that standards are usually better after a good dose of pragmatism and experience so as so many Cloud offers are still in beta this wouldn’t a prudent time.

There is also calls that having Standard’s bodies are little more than exclusive clubs designed to lock competitors out by using the ‘moral high-ground’ of standards as nothing more than a competitive edge, so the questions is whether Standards Bodies are really about benefitting the customer and the industry.

To add to the doubts how many Cloud services have published Service Level Agreements? I getting the feeling that this is still work in progress for many.

In Summary

Bottom line, using cloud computing is a sign of an advanced or very current application. It suggests scalability and availability. It is a cost efficient way to go for most ISVs. But it comes with a cost. You often need to look under the surface to discover if it really is of real benefit to you.

The potential is huge especially if not your organisation isn’t an Enterprise, this technology allows even a humble start-up to compete at the same scale as an established Enterprise.

With Cloud Computing many organisation such as Microsoft, HP and Amazon have committed significant sums on money and will be keen to have returns on their investments hence why the ‘hype-machine’ is going fall-tilt at the moment. The danger of this is that it will attract the same individuals that also hyped SOA that were quick to leave as potential wasn’t immediately realised damaging a perfectly viable architectural approach.

Interesting times for Cloud Computing, I will watch how things develop with interest.

Technorati tags: Cloud Computing

A Developers Guide to Storage. What you need to know but were afraid to ask.

Dave Oliver — Tue, 30 Dec 2008 18:03:20 GMT

Does your software or database run like a dog? Running out of space? Or doesn't recover well in a disaster? ... then your storage configuration may be one of the reasons. This is a short little post just to give you a heads-up on the basics. You may know bits of it already, hence why I have broken it up into a Q&A format so you can skip what you already now.

The Hard-Disk

Well we've all seen a hard-disk but the likelihood is that it was in a desktop and you're the only person that uses it at anyone time? Have you noticed that if you run more than one thing that accesses the disk at the same time, it sometimes slow down?

Hard-disk's are essentially serial devices where a head can only really read or write one thing at a time, they have got cleverer in recent years but still it's a bunch of heads hovering over a set of platters, each head taking it's turn to read or write.

These day's in servers and storage devices you are likely to find are SAS drives or Serial Attached SCSI. You would think that Parallel SCSI, the old standard, would be faster but as speeds increases the problem of timings and keeping data in sync or 'skewed' was proving difficult and expensive. SATA is self 'skewing' so we will see much larger increases in bandwidth in the next few years, typically it is 3Gb/s now this is likely to rise to 12Gb/s in the next few years.

Stripes?

Increasing performance has meant getting more disks then spreading segments of a file across them so each set of heads can read a part of the file at the same time as others speeding up the loading of a file. Hard-Disk in this configuration are said to be 'Stripped'.

Mirror?

Hard-disks have a life, they have moving part and will ware out in-time. However, we can't accurately predict when it will break-down so the simplest form of protecting the data on the disk from it's inevitable failure is making a copy. Backing up the data to another media takes time. To reduce the risk, data is copied to another disk called a mirror at around the same time it as the original. If the original fails the mirror takes over until the original is replace, then the mirror copies it contents to the new original. This is called unsurprisingly 'Mirroring'.

Parity/Error Correction?

Redundancy data is created and stored to allow problems to be detected and/or fixed. The redundancy data is calculated from sets of actual data values.

In detail, since computer data is stored as binary numbers it can use Boolean operators to transform data. One of these operators is Exclusive OR (XOR). The interesting and useful thing about XOR is that if performed twice in a row, it "undoes itself". This allows for calculating any single missing value from a set of values.

What is RAID?

Standard configurations combinations of disks in a Striped, Mirrored, with or without parity combinations are called the RAID (Redundant Array of Independent Disks) with a corresponding numeric for common communication of the configuration.

There are various combinations giving different trade-offs of protection against data loss, capacity, and speed. RAID levels 0, 1, and 5 are the most commonly found, and cover most requirements. Here is a brief summary,

RAID 0 (striped disks) distributes data across several disks in a way that gives improved speed and full capacity, but all data on all disks will be lost if any one disk fails.
RAID 1 (mirrored settings/disks) could be described as a real-time backup solution. Two (or more) disks each store exactly the same data, at the same time, and at all times. Data is not lost as long as one disk survives. Total capacity of the array is simply the capacity of one disk. At any given instant, each disk in the array is simply identical to every other disk in the array.
RAID 5 (striped disks) combines three or more disks in a way that protects data against loss of any one disk; the storage capacity of the array is reduced by one disk
RAID 6 (striped disks with parity) can recover from the loss of two disks.
RAID 10 (or 1+0) uses both striping and mirroring. "01" or "0+1" is sometimes distinguished from "10" or "1+0": a striped set of mirrored subsets and a mirrored set of striped subsets are both valid, but distinct, configurations.

At the heart of any storage solution disks will be in a RAID configuration of some description. The rule of thumb is that the more disks the more expensive so the idea is to keep the costs down by asking where would be the best place to put files. Unchanging files perhaps best placed on RAID 0 or 1 arrays and database files on RAID 5, not everything on a RAID 10 for example.

What is NAS?

Attaching Storage Array's to a network makes them a NAS, or Network Attach Storage.

What is a DAS?

LaCie 4Big Quadra

What is a LUN?

When you request an amount of storage a set of hard-disks are logically grouped together, this grouping is called a LUN or Logical Unit Number. Storage Array's are divided up into LUN's.

What is a SAN?

A SAN concentrates on speed, ease of management and amazing resilience to disaster. It is about moving large volumes of data round quickly and safely.

SAN devices are at the cutting edge of storage technology and have advanced into specialist technologies that typically mean using the fastest mediums possible such as a dedicated fibre-optic networks for example. The Storage Array's themselves can also go a step further than NAS, take the HP Storage Works 9100 for example, 640 terabytes capacity.

The Storage Works 9100 has a shed load of RAM in it acting as a cache protecting you from the limitations of the hard-disks themselves. Ultimately Hard-Disks have there limitations however their days are numbered! As the size increases on Solid State Disk or SSD, these are increasingly being used in Storage Array's such as the EMC Symmetrix DMX-4. Most EMC devices are rebranded as IBM or Dell. The trend is only likely to continue.

Good Questions to Ask

The section covers some Q&A's to help ...

So what other applications are using the same Hard-Disk on the SAN? Could this explain those unpredictable slow downs?

Certainly Yes! Let me give you a typical example. SQL Server creates a file called TempDB, this is were it stores stuff it's workings out. If accessing TempDB slows down, SQL Server will slow down, looking at Task Manager isn't going to tell you that.

A typical reason why TempDB is slowing down is because the file is sharing a Hard-Disk with some other files that are getting accessed at the same time.

It is recommended that a TempDB file is created for each processing core just make sure that they aren't all sitting on the same Hard-Disk. For optimum speed make a TempDB file sit on a Hard-Disk all on it's own. Sounds like a waste? No, not if several databases and their queries are hanging off that TempDB file specially if you can get more performance out of existing SQL Server machines you won't need to buy more.

Should the file block size change?

Some applications read data in specifically size chunks at a time. SQL Server's is 16 kilobytes for example. So it makes sense that the Hard-Disks to also reads and write with the same block size as the applications it's serving.

Can storage help with Disaster recovery?

Many storage solutions are built with DR in mind and will not only copy data to another disk in a mirror setup but copy that data to another Storage Array in another Data-Centre. As you can imagine with the complexity of this operation there is more than one way to do it. For example Symantec Veritas Volume Replicator will create an exact copy in another Data-Centre be transferring only block level changes over an IP network keeping network traffic down.

However there is a debate whether technologies like Veritas Volume Replicator are good alternative to say SQL Server Database Mirroring, as Volume Replicator sends exact block level changes where Database Mirroring will send SQL commands that can update an infinite level of data depending on it's instruction, both of which can be sent over the same IP network but only works with SQL Server 2005 and above. So you can see there is pro's & con's.

The Checklist

This section covers question that your storage team will want to know about the software don't always rely on Business Analysis, Architects or Projects Managers to supply this information, better to have it twice than not at all even if you can't fill it all in.

Questions about the Software

Initial Amount of Storage - how large will the system be when it goes live
Storage growth - 6mths- 12 mths, 18mths, 3yrs, 5yrs
User Growth 6mths - 12 mths, 18mths, 3yrs, 5yrs

Storage & Capacity planning teams can work out when is the best time to buy more storage.

SLA - Survival Critical,Multiple Business Processes Critical, Business Process Supporting, Day to Day, Nice to Have - Business Day - 8am-6pm, 24hrs, World Region EMEA/ASIAPAC/AMERICAS
Most Frequent Time of Use - End of Month? End of Day? No Peak?
Business Users and Location
Support Team

Storage Teams are operational so will want to know who they need to talk to if things go wrong or want to organise upgrades or outages.

Questions about the Files

File Name/Set - Size, Growth, 12 mths, 18mths, 3yrs, 5yrs
Description of Use
Type - Sequential/Random
Performance Required <25ms <100ms

Answering these types of question will help determine what type of RAID the file will sit on and the DR whether a local Data-Centre or who knows, it could be on the other side of the world!

In Summary

You don't have to become an expert in Storage, I'm not. Having an appreciation certainly is an advantage as it is a key subject of enterprise computing which many can wrongly believe they are abstracted from but clearly aren't, infact the opposite, total dependent on. Getting your head around storage could be one of those things in grow that 'Developer X-Factor' that turns you from a good developer to a great developer!

Technorati tags: Software, hardware, development

Infrastructure Appreciation for Developers.

Dave Oliver — Tue, 30 Dec 2008 17:55:12 GMT

Hardware and Software are very much the modern day Yin and Yang, one serves little purpose without the other.

I have noticed that on the whole many developers know little about the environments that the software they are writing is going to work in falsely believing they are truly abstracted from it . Come 'Go Live' there are blank faces when for some 'inexplicably reason' the software doesn't work and the remark, 'it worked fine in test' is often heard.

Another common frustration is software that doesn't perform well from the start or starts to slow down after go live. Again blank faces and scratching of heads can be seen. All of this can be avoided not only by having better working practices and more testing which is well known but knowing more about the hardware dependencies on which the software relies which is less well known.

To help I've written a few handy guides on topics such as Storage, Servers, Networking and SCOM from a developers perspective. I believe having this knowledge is part of developing that X-Factor that makes a good developer a great developer!

Each guide will have some handy questions you can ask to get a greater understanding of your environments and some of my rules of thumb that you may find useful, I have deliberately kept the signal to noise ratio down. The first in the series is on Storage.

Developing an Infrastructure appreciation is a good way to help bridge the divide between the software and hardware camps and would make a great subject for a book. Now if any publishers are interested please drop me an email.

Anyway, I hope you enjoy. Feedback positive or negative is all most welcome.

Technorati tags: Software, Hardware, Development

Which Enterprise Architecture Methodology do you use?

Dave Oliver — Sun, 10 Aug 2008 15:24:00 GMT

There is a bewildering array of Enterprise Architecture methodologies so it will be of great interest to me to find out which one people are actually using, if at all.

So to find out, I have put together a pick poll so please take the two minutes and leave your choice.

You get a chance to select up to 3 options because I suspect that people are using a combination of more than once approach, rather than following one prescriptively.

This is purely for interest purposes, I'm not going to use this data for marketing. I'm also sure it's not particularly scientific but it is chance for you to express your opinion.

The poll is here on the EnterpriseArchitecture.co.uk forum.

Technorati tags: Enterprise Architecture

Help your organisation to go Green, use Enterprise Architecture?

Dave Oliver — Thu, 24 Jul 2008 16:33:01 GMT

Paul Homan recently commented on Green EA which set my mind thinking ... 'being more Green' is a strategic ambition and what is the process and practice for generating strategic change? Enterprise Architecture! When EA's are struggling to find some ROI reason to justify their existence in the economic down-turn amazingly one of the main ROI reasons is one of the biggest issues of our time as the 'Return' doesn't literally mean monetary and also doesn't necessarily mean more? ... it can also mean less, as in less carbon release, less waste produced and less energy used.

Often companies are looking for quick, hand-to-mouth change to make an immediate impact but often these changes are to radical or not radical enough, either way will need draconian measures to keep them in effect. Good strategic change happens in steps and not sweeps.

A good example is the profile of electricity consumption throughout the day. As you can see from the graph of total electricity generated in the UK in MW over half hour periods taken from today's Elexon's BMReports website yesterdays power consumption profile is similar to today's.

Much of the electricity is generated by coal and gas power-stations, by reducing the amount of electricity generated by these power-stations is the goal.

The two pronged attack is,

1) Reduce the overall demand for electricity

2) Replace whole or inpart the electricity generated by coal and gas power-stations with generation methods that do not give off large amounts of green-house gases.

I should say that many would like to take this go a step further and use generation methods than have little environmental impact such as wind, wave, solar and thermal to name but a few. I personally love this but am aware that to get here a lot more research and investment from everyone is required.

Whilst I'm on the subject we may as well talk about nuclear. Here in the UK we have had a good safety record with nuclear mainly due to the very British safety obsessive attitude brought about by culture. Nuclear cannot ramp up or ramp down in energy production as fast as coal or gas so is used for the large volume sustained underlying amounts of energy which is called the Base-load. The idea in the UK is to reduce the amount of Base-load produced by Gas and Coal and replace it with nuclear.

My very personal view is that I am happy about this as long as nuclear itself is a medium term answer and will itself be replaced by other forms when they are suitably advanced enough and man enough for the job. So whether you believe in global warming or not it does make common sense to reduce the amount of CO2 in the atmosphere to improve air-quality and it does make sense to reduce the amount of electricity we consume. These are noble ambitions no matter your political stance.

Anyway we haven't strayed away from the point, just merely demonstrated it. Good strategy comes from providing goals and coming up with board solutions which launches initiatives, then programmes of work, then projects. All the time testing whether things are right and have the strength to stop them when they are wrong, even testing whether the strategy is right. However the basic misnomer is that strategy is a plan.

So can you imagine the chaos if the Government decided to solve the problem by rationing electricity? Ok so this wouldn't happen because Government understands the criticality and how much is dependent on electricity, the steer is that it is obvious how much electricity is relied upon. We as Enterprise Architects could learn many lessons then successfully communicate them about what is the critically of things purely by understanding what is dependent on them.

The challenge is that Enterprise Architects really do need to become the green champions of our organisations by understanding what is consumed and wasted, then working with the business to decided on goals then formulate strategies and place in measures and governance to ensure these strategies and tested and the goals met. We are after all ideally placed to take on this responsibility so we shouldn't hide from it.

So here is my challenge to all Architects that have blogs, write about going green as we need to spread the message that solving these problems is everyone's responsibility.

Technorati tags: Enterprise Architecture

Lite EA is renamed Coherent EA

Dave Oliver — Tue, 22 Jul 2008 02:57:29 GMT

John Wu is a good guy. Out of respect for Fenix Theuerkorn and his work on Lightweight Enterprise Architecture, John has decided to rename his EA Methodology from LiteEA To Coherent EA.

Coherent EA is a actually a better, more descriptive name for John’s work IMHO and as a regular contributor to the ITToolbox conversations his methodology has the benefit of faster development from genuine experience than most of the others I could mention.

I certainly have benefited from Coherent EA in the past and think that it is a great resource, so I for one will be updating my book-marks.

The Open Groups SOA Ontology

Dave Oliver — Thu, 17 Jul 2008 02:51:52 GMT

The Open Group has recently released a draft version of a SOA ontology.

The Open Group has always had a mandate to help boundaryless information flow and the ontology (specification of conceptualisation) for SOA is a demonstration of just that. The ontology is written in the Web Ontology Language (OWL) defined by the World-Wide Web
Consortium and this for me is what makes it a hurdle to learn as it's not an intuitive meta-language but then is any? Perhaps if it wasn't for the graphical tools we would get stuck.

Open Group explains the benefits as:

1. It defines the concepts, terminology and semantics of SOA in both business and technical
terms, in order to:

Create a foundation for further work in domain-specific areas,
Enable communications between business and technical people,
Enhance the understanding of SOA concepts in the business and technical
communities, and
Provide a means to state problems and opportunities clearly and unambiguously
to promote mutual understanding.

2. It potentially contributes to model-driven SOA implementation. The ontology is designed for use by:

Business people, to give them a deeper understanding of SOA, and its use in the
enterprise;
Architects, as metadata for architectural artifacts; and
Architecture methodologists, as a component of SOA metamodels.

The full draft can be found here:

http://www.opengroup.org/projects/soa-ontology/doc.tpl?gdid=16940

After reviewing the draft I am left cold. My first opinion is that business will find this difficult to adopt in the same way they found UML difficult. Why because they are both coding languages, you may as well stick in a 'Print' command. The gap between logical design and executing code is a large as ever.

I still hold the belief that business and IT can only really align on the logical level. Business doesn't want to know about detail they will want to be abstracted away from that, this is actually a key SOA deliverable, just a very unspoken one, hence why REST services appeal. I believe that IT cannot handle business logic detail on it's own, so alignment between business and IT will come when hybrid groups formed of technologically minded users and business oriented IT exist to make, maintain and specialise in services that support their business area based on IT standards and underlying IT technologies and services.

Why I believe these groups need to exist is because business and IT can never align because they have very different goals and therefore different headings. Align the destination and the groups will align, not possible with business and IT as they are very different by reson d’etre. You can't marry creatures of different species. You can however translate and interface.

These groups do actually exist all over successful organisations they just lack boundary, form and recognition perhaps even by the very people that make them up. E.g. So you code in a Spreadsheet? So do you report to the Sales-Manager or Dev Team Leader?

Back to the Ontology, I think the Open Group need to ask a fundamental question, how does business see and understand logic? I really do think we need to revisit DSL's.

Technorati tags: DSL, SOA, Open Group, Ontology

The first problem with Enterprise Architecture is the name!

Dave Oliver — Wed, 25 Jun 2008 23:32:34 GMT

Job titles are often effortless in their descriptiveness. Project Manager, Business Analyst, System Tester and .Net Developer are good examples because the subject is concise and the predicate modifies successfully, all meaning some semblance of what a person does can be derived from it.

However with 'Enterprise Architecture' and 'Enterprise Architect' it’s not entirely obvious what the position is and what someone holding that position does, inevitably leading to the need for further description which predictably stumbles into the second problem, the woefully dire and contrasting descriptions of that we do that litter almost every Enterprise Architecture methodology and practitioners blog. No wonder the meaning is different from organisation to organisation and therefore what an Enterprise Architect does (or doesn’t) and get involved in. Inconclusion the Enterprise Architect is hindered from the get-go.

So what are the solution options?

1) Educate everyone on Enterprise Architecture – Many are hoping that time and tide will eventually solve this one but without a united vision I fear that this is little more than a hope.

2) Break-up Enterprise Architecture into it’s constituent parts and give each one an individual role – More realistic as this ensure that the activities under Enterprise Architecture have individual focus and therefore are likely to happen rather than get lost, diluted or ignored.

What do you think?

Technorati tags: Enterprise Architecture

Am I an Armchair Architect?

Dave Oliver — Thu, 12 Jun 2008 20:32:11 GMT

According to James McGovern, I probably am! Why? Because I don’t code … very often.

I don’t sit in an Ivory tower either making up my dictions via, Visio & Powerpoint. I think the key to being a good Architect is taking responsibility for designing a technical solution for business requirement with those who are going to built it, implement it, look after it and use it.

Making good technical decisions often means getting your hands dirty and trying afew things out, if that is writing code or testing a device or installing a server then whatever it takes. However, Architects shouldn’t try to be heroes and experts at technologies but have the courage to go form relationship and seek opinions of those that are, I think that this is the real point.

Ok, so an Architect therefore is more about diplomacy, relationships and pulling strings together, it isn’t an adversarial role, it’s point is to generate a solution to a business problem where everyone that is playing a technical role knows what they have to do.

Architects shouldn’t pretend to be experts in technologies, they should know when to leave things to the professionals and not to meddle and step back and let them do their jobs. Architects can’t keep up with best practices in all technologies, there isn’t enough hours in the day.

I believe that an Architects mindset has to be different from that of a lead developer or technical guru as an Architect has to be technically agnostic and objective, whilst a lead developer or guru has to be an expert in chosen technologies, can you see the difference? One is a specialist in a technology the other is a specialist in a practice that requires a passion for all technology. Often Architects are consider as the technology ‘point-man’ for a project and first point of call for all things ‘techie’ for a Project Manager.

So can an Architect specialise? Yes because technology is such a vast set of topics I can’t see how Architects can’t specialise in a field but it then becomes a balancing act where technology meets good architecture principles meets business direction, where as a developer or IT Pro need to become honed in their art whether they use an aspect of a technology at that moment in time or not, form opinions and even become bias, these are not luxuries an Architect can afford.

So if you are a developer or IT Pro and reading this and say … 'but I do that this stuff already', I would reply, 'good for you!' Because obviously you are capable of performing more than one role, don’t get the two confused.

Technical Architecture

Microsoft’s UK Architecture Resources

What is all the fuss about Cloud Computing?

Trendy

Cost effective

High availability

Operational Simplicity

Financial Scalability

Cons

In Summary

A Developers Guide to Storage. What you need to know but were afraid to ask.

The Hard-Disk

Stripes?

Mirror?

Parity/Error Correction?

What is RAID?

What is NAS?

What is a DAS?

What is a LUN?

What is a SAN?

Good Questions to Ask

So what other applications are using the same Hard-Disk on the SAN? Could this explain those unpredictable slow downs?

Should the file block size change?

Can storage help with Disaster recovery?

The Checklist

In Summary

Infrastructure Appreciation for Developers.

Which Enterprise Architecture Methodology do you use?

Help your organisation to go Green, use Enterprise Architecture?

Lite EA is renamed Coherent EA

The Open Groups SOA Ontology

The first problem with Enterprise Architecture is the name!

Am I an Armchair Architect?