Development Technologies

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

Dave Oliver — Sat, 24 Jan 2009 18:24:49 GMT

Servers are the backbone of enterprise computing today, most websites for example run on either Apache or IIS and will be running on a server of some description.

Perhaps because of servers ubiquity it is easy to become complacent about them especially as they are rarely seen but understanding what a server can offer you and it's limitations will definitely help with software development.

Servers on the whole are built more of the practicality side than for the esthetics, there is no need to make them look pretty if they are going to spend most of there time in a Data-Centre rarely seen. The server will only have a visit if something goes physically wrong, everything else should be looked after remotely. Ultimately the success of a server is measured in the the amount of time spent looking after it and it performing the task(s) you have set it.

The Differences Between Servers and Desktops

The main difference between Servers and Desktops are Servers are designed to run 24/7 desktop aren't. The components in a server can usually handle higher stress and handle redundancy by having two or more of critical components so if one fails there still is another keeping the server up and the service it is running available.

The Different Types of Server

There are different types of server then mains ones are,

Pedestal/Tower

A Pedestal Server (which is often know as a Tower) isn't rack mounted as the main intention of it's design is to work primarily in an office environment not in a Data-Centre. These machines are usually found as file or print servers.

Rack Mounted

As the name suggests a rack mounted service lives in a rack. Placing servers on top of each other in a rack to support their weight and to provide them with services such as power and networking means that you can have lots of servers taking up less room and room in data-centre's are at a premium. A typical rack is 19 or 21 U (I will explain later what a U is)

Enterprise Class

Enterprise Class servers are free-standing like pedestals but you won't find them in an office! Because of their size, value and special requirements such as multi-phased power supply, larger than domestic voltages or specialist cooling they can only really live in a data-centre. As you can imagine this type of server doesn't come cheap. Enterprise Class machines would have been called 'Mainframes' in year gone by but as they run can happily run operating systems such as Linux, Unix and Windows (The IBM P Series pictured does not run Windows). Their main function today is as a consolidated platform as one of these servers can run the equivalent of several hundred Linux servers saving space and power.

Blade

In a typical rack you can get about 10 rack mounted servers. Blade servers on the other hand are designed for high density, i.e. more servers in the same amount of space. Take for example the HP C Class Blades, a U10 C7000 Blade Enclosure can have upto 16 468c G5 Blade Servers. So a normal rack can have 32 servers in it rather than 10. Blades servers make ideal candidates for hosting Virtualised servers such as Vmware, Hyper-V or XenSource.

The Worlds Most Popular Server

It is estimated by HP that the world most popular server is the ProLiant DL380 G5. As I haven't seen this claim undisputed I will use the DL380 as an example of a typical server as it is the one you are most likely to meet. This next section will give you a detailed overview of the machine.

HP's Official ProLiant DL 380 Overview

Front View:

1. Eight sockets for PC2-5300 Fully Buffered DIMMs (DDR2-667) - up to 64GB RAM is possible

2. Hot-plug fans, full redundancy - air is sucked through the machine from front to back.

3. Systems Insight Display

4. Quick release lever for rapid server access - lifting these levers will allow you to quickly pull the machine out of a rack.

5. Support for eight Small Form Factor hot plug hard drives bays - Typically SAS drive (discussed in the article on Storage) are installed here.

6. Front LEDs (show server status) and Unit Identification button/LED (for easy in rack server identification)

7. Two front USB ports (2 rear USB ports, 1 internal USB port)

8. Intel Xeon Processor (Performance models include two processors)

9. Hot plug power supply, redundancy option (High performance models include redundant power supply) - Yes two power supplies. One can be replaced whilst the server is still working for maximum up-time.

10. Three full-size PCI-E expansion slots in standard expansion cage (or optional mixed PCI-X/E expansion cage). Two additional low-profile PCI-E slots embedded on the system board. Four slots available for use; one consumed by Smart Array controller (Base and Performance models)

11. Quick removal access panel

Rear View:

1. Torx service tool - HP exclusively use a standard screw-driver head in their machines called the Torx T15 to help avoid screw-driver cam-out.

2. Optional pass through cable door

3. Two Embedded NC373i Multifunction Gigabit Server Adapters with TCP/IP Offload Engine

4. Hot plug power supply bays, redundancy option (High performance models include redundant power supply)

5. Integrated Lights-Out 2 (iLO 2) Remote management port. ILO is a remote management console that can turn a server on and off and take over the screen amongst other features. ILO usually has it's own dedicated VLAN. I will talk more about what that is in A Developers Guide to Networking. What you need to know but were afraid to ask.

6. Video Port

7. Two USB 2.0 Ports

8. Serial Port

9. Keyboard Port

10. Mouse PS/2 Port

11. Two low-profile PCI Express x8 slots. Slot 1 is consumed by the P400 Smart Array controller. (Base and Performance models)

12. Three full-size PCI Express slots in standard cage (or optional mixed PCI-X/E expansion cage)

Specifications

Processors:
- Quad-Core and Dual-Core Intel® Xeon® processors - systems support up to 2 processors
- Intel® 5000P chipset
Memory:
- Up to 64 GB PC2-5300 Fully Buffered DIMMs (DDR2-667)
Storage Controller:
- Performance Models: 512MB (RAID 0/1/1+0/5/6)
- High Efficiency and Base Models: 256MB Controller (RAID 0/1/1+0/5)
- Entry Models: 64MB Controller (RAID 0/1/1+0)
Internal Drive Support:
- (8) small form factor (SFF) hot-plug drive bays to support Serial-attached SCSI (SAS) and Serial ATA (SATA) drives
- Slimline media bay supporting Optical or Floppy drive
Network Controller:
- Two embedded Gigabit Network Adapters
Expansion Slots:
- Four PCI-Express slots
USB Ports:
- USB 2.0 support
- 5 total ports: (2) ports up front; (2) ports in back; (1) port internal
Integrated Hypervisors (Optional):
- VMware & Citrix XenServer virtualization technology ... sadly not Microsoft yet!
Redundancy:
- Fully redundant hot plug fans (N+1)
- Hot plug power supply with optional redundancy (Included in Performance models)
Form Factor:
- Rack (2U), (3.5-inch); Depth 26 inches (66 cm)

What is a U ?

A 'U' or Rack Unit is an Electronic Industry Alliance standard height (EIA 310) measure for a rack mounted server. The reason there is a server is so machines from multiple vendors can all use the same racking.

A U or 1U equates to 1.75 inches or 44.45 millimetres. A typical rack is either 19 or 23 U's high. Our example machine the HP DL 350 G5 is 2U (see Form Factor in previous section)

Good Questions to Ask

One of the most frequent question there is, is why is the system running slowly?

Often the answer to this question is one of the four resources on a server is getting maxed out. CPU, Memory are obvious but the problems usually lie with I/O in the form of networking and disk. So understand what networks the servers is connected to and what storage and how it is configured. Recently I found a SQL Server database was running like a dog because the mdb file was sitting on the same hard disk as many others so the disk was working flat out! However to solve the problem developers were off writing better SQL and .Net code which won't have helped at all.

Is the Live server the same as the Dev? If so, what else is the Live server running?

'It runs ok in development' is frequently heard and we all know that if development and testing environments could accurately simulate a Live environment then more problems could be found before go-live. A far easier thing to do is measure how much resource your new development consumes and profile it over a working cycle such as a day or through a month-end process, then examine the servers it's going to go live on, and watch the server through the same profile you will get a better idea whether your new development will fit, this will be easier than trying to reproduce a Live simulation in test or dev but if you can do that, that's great!

In Summary

I do like hardware! So I am bias but I do believe that getting to know hardware can help bridge divides and help solve problems because if programs don't work well infront of business users the whole of IT looks like smucks and the 'his fault not mine' looks extra lame.

Technorati Tags: Hardware,Developement

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

Why Developers & Testers will LOVE Vmware's Lab Manager

Dave Oliver — Mon, 14 Jul 2008 02:02:20 GMT

Vmware currently is going through the wars. A change of CEO, a plunging share-price and a competitor getting alot of attention with their new product, that being Microsoft with Hyper-V. However, I just don't get it!? ESX Enterprise is still out in front in terms of features and pricing is very competitive. Any organisation performing their own unbiased product comparison evaluations is going to be hard pushed to discount Vmware's flagship product. The killer feature for many is ofcourse Vmotion that sadly none of the competitors have an answer for. So Vmware has it all to play for.

Another area that the competition hasn't got an answer for is meeting the specific virtualisation needs in the development and testing arena's. Vmware has an offering here with the Lab Manager products.

Vmware Lab Manager enables Software Developers, Testers and Support Personnel to suspend, then capture to a shared storage library, a complete state of configurations – or collections of running interdependent systems that span multiple servers.

Over time, a library of configurations, including test scenarios, production environments and system configurations can be built. When a configuration in the library is needed later for development or test purposes, for example to test a new software build in the context of an .Net developed environment, Vmware Lab Manager can deploy an exact copy of the entire configuration to the best available resources in a pool of managed servers, running and ready for use. Further, the network fencing technology of Vmware Lab Manager can let multiple users deploy copies of the same library configuration simultaneously, without having to change machine characteristics such as IP addresses, MAC addresses, or security IDs and have normal network access.

The main benefits of Vmware Lab Manager are,

Reduce equipment-related capital and operating expenditures
Accelerate integration and system testing
Shave time off software development projects
Increase the number of configurations a new system supports
Enabled for unit and functional testing
Reproduce bugs and reduce time spent in the debug phase
Reduce the number of latent software defects that slip into production
Reduce upgrade breakage
Better management of joint resource across teams

Indirect benefits are,
Delivering better product support
Easer troubleshooting for customer production problems
Improved productivity and efficiency
Reduce time finding spare servers
No need to hoard servers and storage
Save power, space & HVAC

The technical benefits are,
Provision systems quickly.
Restore previous configurations.
Restore previous sessions “in state.”
Quickly make changes to a configuration, possibly via user self-service.
Dynamically expand and contract resource allocation
Quickly save existing configurations via hot-saving capabilities
Schedule usage
Recycle system resources for other uses.

With VI3, systems are handled as single images (i.e., not as an interconnected “set” of systems that comprise a particular multi-tier environment), so there is still a lot of manual configuration required. Further, without Lab Manager’s centralized library of multi-tier systems, organizations run the risk of “VM sprawl” – that is, VMs that are randomly stored on file servers, which are difficult to manage and share effectively.

The key components in a Lab manager configuration are,
Lab Manager Server – A server that provides Web and SOAP interfaces to interact with Lab Manager. The Lab Manager Server system manages and deploys configurations against a pool of Managed Server systems.
Lab Manager Managed Server – A server running Vmware ESX Server and the Managed Server software. The Lab Manager Server system uses the Managed Server system to deploy configurations and their virtual machines. You can have multiple Managed Server systems.
Lab Manager Storage Server – Storage for virtual machines (for example, an ESX Server SAN or NFS server) and storage for media (CD, DVD, and floppy images). You can have multiple storage servers.
Lab Manager Client User – Clients who can use the Lab Manager Web console and the Lab Manager SOAP API. You can access the Lab Manager Web console with Internet Explorer (IE).

The licensing costs aren't horrendous being approximately £9000 for Lab Manager server and approximately £600 per Lab Manager Managed Server. However don't quote me as they are rough ballpark figures just to give you an idea.

This software is ideal for any developer or tester that has tried to stuff multiple applications on the same bunch of servers or screwed up servers trying to take them backwards to a previous released version to try and fix a live bug or the tester that wants to try things out without having to hinder anyone and any number of daily pre-production scenarios where you darn well wished you had your own private set of servers to figure stuff out on.

My last message is to Vmware ... pull yourself together and market this product because it is going to save a lot of good people a lot of hair.

Technorati tags: vmware, hyper-v, microsoft, development, developers, testers, testing, lab manager, virtualisation

Get Answers from Your Peers

Dave Oliver — Fri, 27 Jun 2008 03:23:53 GMT

I have been subscribing to TechTarget emails for sometime because of the low signal to noise ratio covering a broad technology spectrum that is important to me as I'm keen to hear from more than just a few vendors so it comes as no surprise that IT Knowledge Exchange (ITKE) was recently voted one of the 10 Great Media Web Sites.

ITKE is on of those dead-handy site that I keep in the 'Favourites' when I want to find an answer. It's not so good for Microsoft .Net Development questions, better off going to C9 Tech Off for that but for everything else try ITKE first rather than relying on the randomness of Google and then wondering if whether to subscribe to Experts Exchange to get the darn answer to a question because they always end-up somewhere near the top.

OK so why do I like ITKE?

1) It's not like a forum, no wading through pages and pages of stuff to get to the answer. If you can improve on the answer given, you are allowed to using a Wiki-style interface.

2) For asking, answering or discussing questions, you can earn points which then can be use to purchase items, like gadgets. You get more point the better your rating. And they have a competition to win prizes for points.

I recently discovered that they also have a whole bunch of very active bloggers that are experts in a particular field, Anton Venter has just started his blog on Enterprise Architecture and is promising a no-nonsense approach so I'll be watching this with interest.

So, all in all, a good IT community that isn't married to a vender where the content is easy to access that has a unique approach to improving the quality of answers all of which are from peers.

Can Developers Work Inside Virtual Environments?

Dave Oliver — Tue, 24 Jun 2008 00:35:14 GMT

As I've been helping out with VMware I wanted to consider the old question of whether developers really could work inside virtual environments?

As we know virtual environments can help maximise under utilised resources, CPU, RAM, diskspace and save on space, power, HVAC and TCO with centralised support and maintenance.

Another main advantage of virtualised environments that is particularly attract to many developers is the ability to remote work which is a requirement that has become far more common with companies wishing their employees to travel less to reduce carbon footprint or to offshore work. But as development environments are resource intensive it has always been felt that they wouldn't make a reasonable virtualisation candidates.

Also, by moving development operations off local desktop means that developers do not have to carry around the weighty desktop replacement laptops, they have far more options from, a large screen, thin client, keyboard, mouse and network access or sitting in the local coffee shop on their Wifi with the trusty Asus Eee or any combination in between.

After some investigation I've determined that normal code writing isn't very resource intensive at all! Infact the only part that is, is compilations. Even with the wealth of utilities and tools at a developers disposal, the modern day processor handles it with some aplomb. Candidacy looks even better when realised that most development environments are running under 32bit operating systems on typical desktops and laptops with up to 4GB RAM and this is the exception rather than the rule, the average being 1-2GB RAM. This puts things into perspective when the modern day virtual server spec is 4 x quad core with 64GB RAM, so you can see there is potential.

In the Lab

On the flip side of the coin, virtual environments can give the developer access to more options than they currently have! No reason now not to run both Linux, Windows and Solaris, Java and .Net! SQL Server and Oracle! All at once! Or an IDE with as many tools and utils running as possible. Why not the whole darn multi-server application! Why not the Testing and pre-prod environments as well! All of which can be replicated as many times as you wish so you can kit out your team, your division, your company! To a certain point the limit is the imagination! And this is exactly where tools like VMware Lab Manager come in!

Lab Manager has been specifically written for the developer and tester in-mind where whole environments can be built and teared down again quickly. You can even have multiple copies of the same environment running at the same time so no need to fight over servers.

Cutting it with a blade

Dave Caddick pointed out to me that where virtualisation environment like VMware and Citrix still suck is graphically intensive operations.

Citrix has a few more years of experience over the marturist of virtual server and software virtualisation technologies that are still using RDP which doesn't perform as well graphically as ICA.

Dave offers an alternative solution to virtualised environments that still offer many of the savings in power, HVAC and TCO that servers have and that is the concept of the Blade PC's.

Blade PC , is a computer that is entirely contained in a thin, modular circuit card placed in a centralised, secure location such as a server rack. A cable connects the card to the user's display, keyboard and mouse. Vendors of blade PCs include ClearCube and HP .

A blade PC, in contrast to a thin client as it is a complete computer that includes all the components normally found in a desktop PC including the microprocessor, memory chips, hard drive, video card and network card. The blade PC concept is similar to the blade server paradigm, except that the ratio of cards to end-users is one-to-one rather than one-to-many.

Blade PCs are initially more expensive to deploy than the conventional arrangement, in which each station has its own computer box, because associated infrastructure, cards and cabling must be installed. Once installed, however, the blade PC offers a number of advantages over the traditional approach and they are,

Lower administrative, operational and maintenance resource demands
Space savings at the workstation
Ease of adding and relocating end users
Reduced workstation noise caused by fans and hard drives
Reduced work area heat generation
Sharing of certain accessories such as uninterruptible power supplies
Improved physical security by placing critical hardware in a central, locked location.

Be Brief

Amazingly, some software companies do not offer licensing for virtual environments which is pants! And very often virtual environment don't support specialised hardware so do your homework.

So you can see there is a number of different avenues open to the developer which are easy to justify. There is no point in trying to stuff everything into that 'paving slab' of a laptop as there is no longer any need, I believe once you get over the fear of giving up a bit of control you will feel the liberation! However it's not like going commando as virtual environments offer amazing support, eventually you'll hardly notice the difference and wonder what all the fuss was about!

Technorati tags: VMware, Blade PC, Lab Manager

Who Will Write Tomorrows Code?

Dave Oliver — Thu, 03 Apr 2008 13:54:17 GMT

The BBC's Bill Thompson in his recent blog post about the state of IT development in the UK has hit the nail on the head

"Universities have seen applications for computer science degrees fall off, schools do not encourage students to do computing at GCSE and A Level and primary school children are trained as users not as programmers."

Recent reports from the CBI (Confederation of British Industry) and CEBR (Centre for Economics and Business Research) indicate that skilled migration workers, specifically in IT and Telco sectors, will significantly contribute to the UK economy and be instrumental in its future growth. So why isn't this capability grown here? It's almost like government and business has actually given up as the direct labour cost is cheaper else where. What I find fascinating is the in-direct costs such as longer lead-times aren't measured so we have no idea how much of an impact that is having or how much of a competitive advantage we are giving away. E-Petition on the Number 10 UK Government website about providing better support for out of work software developers and IT workers adequately demonstrates the lack of interest for issues effecting developers by the lack of signatories where some more inconsequential petitions have a significant amount more. The diminishing amount of UK developers is just not seen as an issue of national concern when it is pretty clear that our economy utterly relies on technology.

I feel this is a narrow sighted view not because I'm a complete xenophobe but as recent evidence suggests the cost of living is going up in the countries we are typically out-sourcing to, with rising inflation meaning wages will rise as a consequence. So as a prediction, cheaper offshore workforces are only going to be true for a period of time. Perhaps in as little as 10 years, wages will rise to a comparable rate between here and aboard nullifying the advantage of having an offshore but will we have sufficient development capability left in the UK to meet our economic needs or let it dwindle leaving us little choice.

So if we want to avoid this future wouldn't it seem prudent to incourage our young to take up carrers in computing now as protection for our future or as another option encourage IT workers from outside to settle here? Whatever option we chose, I believe we cannot afford to allow our development capability to diminish as it is a core skill which our economy does and will continue to depend.

Book Review: SOA Approach to Integration: by Ramesh Loganathan, Poornachandra Sarang, Frank Jennings, Matjaz Juric : Published by Packt Publishing

Dave Oliver — Tue, 01 Jan 2008 00:44:12 GMT

Selling the theory for SOA is pretty easy, the execution is harder because technically it isn't actually a very simple thing to do, let alone the changing of the structure of your IT organisation to house-keep.

The book SOA Approach to Integration is aimed fairly and squarely at the Architect and Senior Developer who has the job of designing and implementing SOA technical level. The book is very resolute in keeping a strong focus on the technology and pleasantly realises that successful integration needs to take place across technological boundaries. Seems pretty obvious but I have a whole host of SOA books gathering dust because they lean heavily towards one technology and one approach. This book refreshingly avoids that, even avoid tasty new SOA areas such as composite applications and REST.

The book takes the reader through the basic principles using patterns to demonstrate many classic integration techniques. Sample code in Java and .Net and takes you through the interoperability story between these two mainstream development environments. Sadly this is where I found my first real criticism of the book, the book does not cover Microsoft .Net 3.0 and WCF or indeed any of the work performed by the Open SOA group such as SCA and SDO. I know that both technology frameworks are on version 1 but developers will be keen to use these frameworks and will feel license to do so as they aren't in beta.

One of the major problems with writing highly technical books is communicating complex points, this isn't very easy without diagrams. The book excels here because it's stuffed full of them, 92 diagrams (or there about's) and many a point sails across because of them.

Most of my list of key SOA points are covered but the books core strengths are BPEL, XML Schema's, Web Services and establishing an ESB, subjects it deals with a high degree of expertise second to none. However specific applications are not mentioned much but one of the clear aims of this book is to stay tech-neutral and keep to the keys points and I would like to thank the authors for that. It is a rare treat to see advice separate from opinion.

So would I use this book to advise me on my next SOA project? Most certainly yes! I can see it being my companion to many a design meeting and delving into it's pages for nuggets of advice. However comprehensive this book is not, thankfully it would therefore become a huge unwieldy tome and no use to man nor beast so I thank the authors that they keep things brief and to the point and at 351 pages not something that is going to weigh your brief-case down.

One very small point, I have been reading this book over Christmas and not one person thought to pick me up for reading a 'techie book' I suspect this is down to rather delightful butterfly on the cover. I wonder how many times that saved me from washing up?

Book: SOA Approach to Integration

Authors: Poornachandra Sarang, Frank Jennings, Matjaz Juric, Ramesh Loganathan

Publisher: Packt Publishing

Here from Amazon UK , Barnes and Noble & Packt

Technorati tags: SOA, Integration, BPEL, XML Schemas, Web Services, ESB, PackT Publishing

Codename "Oslo", Microsoft's next generation SOA thinking.

Dave Oliver — Tue, 04 Dec 2007 04:51:49 GMT

Oslo is the codename for technical thinking aimed specifically at simplifying designing, building, managing and scaling of service-oriented and composite applications that can span from the enterprise to the Internet.

It is thought the first version of Oslo will be delivered through the next versions of our application platform products such as Microsoft Visual Studio 10, Microsoft System Center 5, BizTalk Server 6, BizTalk Services 1 and Microsoft .NET Framework 4. So, we are talking a 18 months to a few years timeframe.

Microsoft in the past has been strongly criticised for it's SOA initiative for many different reasons which are,

Not having a comparable product range with most other vendors, making vendor selection harder.
Not adopting the same standards as other vendors, specifically in BPEL. For my mind this is a mute point as most vendors implement different versions of BPEL support in their products. The same cannot be said of WS-I WS-* standards for web services as Microsoft have supported their development using WSE extensions to .Net 2.0 and later on with WCF with .Net 3.0.

Reading the Oslo website my main concern is I'm seeing little emphasis on common standards and interoperability which for me are the main reasons why organisations decide to implement a SOA policy. So the question I'm asking is, is it really all about designing, building, scaling and managing .Net applications better which in the past has not been the strong suite of Microsoft which has made organisation go to third parties for products and advice to solve these problems.

The reason why we know about Oslo at all is that Microsoft want to have a conversation with us which is something they are getting better at however there is no blog to link to, no entry on a forum or C9 so I'm looking for somewhere where I can have that dialogue with Microsoft, hence the blog post!

Technorati tags: SOA, Oslo, Microsoft, .Net, Biztalk

Is the Open Source debate important to Enterprise Architecture?

Dave Oliver — Fri, 30 Nov 2007 02:46:03 GMT

I first started coding at the age of 10 on a Commodore Vic 20. Last week I finally un-installed Visual Studio 2003 on my laptop because I need the space and I never touch it. It was sad admitting that I don't code and my role does not require me to. If I did find myself coding then I probably shouldn't because there is so much else to do and we have more than a few guys and girls that will happily do the job and only a couple doing EA.

Yep, I get the argument that a good architect should have more than an appreciation of what code can do and the only way to find that out is to code something. Sadly that argument doesn't wash with Enterprise Architecture because it's not about designing software solutions at all, not at any level. Hence why a person from a business back-ground can happily be a very good Enterprise Architect, technical skills are not a primary requirement, an appreciation is fine and the ability to find out and ask the person who would know best is better.

So do I miss coding? No, to be frank. I have done my time and now I want the new challenge. However, being an Enterprise Architect means that I have to put the benefit of the business before vendor elegance's. Infact I find yourself having to take a position of complete neutrality to allow yourself to get to a place to see the big picture. So being a coder in .Net, being an advocate of .Net to suddenly realising that I can no-longer do that as now technology choices aren't mine to make, infact benefiting the business means that I can end up eventually promoting solutions written by the other team and if it fulfills requirement, then that's what it's all about. As you can imagine a weird position to be in for someone who spent so long being a Microsoft evangelist because it kept my boys and girls in work!

One of the big debates in development these days is to write, contribute and use Open Source software, the pro's and con's of the debate I'm not going to dwell on here as many people have done it so much better than me. I agree that half the battle with Open Source is mind-set and whether you can get your head round it. The assumption is that if you develop code in .Net you must be into close source and this is actually far from the truth. Being a contributor to Open Source projects in the past, I get it and I love it! It is a bit more that really cool software for zero price but boy is that a killer reason. I got a kick out of watching the download count go up and realising that people were using my code.

Now I find myself in a place where this debate must have no bearing on my role as an Enterprise Architect for the same reason as I can't advocate .Net as the result could cloud my judgement. Yep, I get I'm allowed preferences but not if they get in the way.

Ultimately Enterprise Architecture is about knowing where you are now, knowing where you want to get to and giving a guide on which type of roads to take and whether the vehicle needs to be big or small, but whether its a Ford truck or a Honda bike driving down the M3 then the M25, that's not your call anymore.

Do you agree? Post a comment, I would love to hear your opinion.

Technorati tags: Enterprise Architecture, Open Source

Development Technologies

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

The Differences Between Servers and Desktops

The Different Types of Server

Pedestal/Tower

The Worlds Most Popular Server

Front View:

Rear View:

Specifications

What is a U ?

Good Questions to Ask

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.

Why Developers & Testers will LOVE Vmware's Lab Manager

Get Answers from Your Peers

Can Developers Work Inside Virtual Environments?

In the Lab

Cutting it with a blade

Be Brief

Who Will Write Tomorrows Code?

Book Review: SOA Approach to Integration: by Ramesh Loganathan, Poornachandra Sarang, Frank Jennings, Matjaz Juric : Published by Packt Publishing

Codename "Oslo", Microsoft's next generation SOA thinking.

Is the Open Source debate important to Enterprise Architecture?