Just Like Google ;-) 15 May 2008
Posted by Olivier Van Acker in Uncategorized.Tags: cloud computing, google, v-base, virtualisation, virtualization, xen
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Because of the way our funding works we had to buy the hardware for the back end of this project relatively early. So at this stage of the project we have two beefy servers. Both have two dual core processors with loads of memory and underlying this we have half a Terabyte of storage for the database (that is a lot of volunteering opportunities ;-P ). To make optimal use of this hardware we decided to use Xen virtualization. With this technology you chop up a single server into multiple ‘virtual’ servers. Meaning: you can run multiple OS’s on a single piece of kit.
In back end application building it’s commonly thought good practice to dedicate a specific task to a single server. So if a single server crashes it doesn’t tear down the whole application. Also, running software in separate servers prevents them from interfering with each other and makes it easier to upgrade and maintain them. We have, for example, one big Oracle database server and several Java application servers all with different tasks.
Another big advantage is that the file system of a virtual server is stored in a large, single file, in our case stored on the storage device, which is a redundant raid5 setup. This has two advantages: If the hardware of one of the servers breaks (cpu meltdown or something similar) we can just login on the other server and start the same(!) server from there (this can also be automated). And the other big advantage: if we want an extra server with the same functionality (e.g for clustering), the only thing I have to do is make a copy if that big file and fire it up next to the original one; no lengthy installation processes anymore once done 
In the final setup one server will function as the main server with the other one as backup in case the main one gets struck by disaster. Normally this would mean that the fail over server would gather dust and do next to nothing. Not with us! We use this fail over server for all our development, experimentation and test server needs. All set up as virtual servers of course. And in a case where the main server breaks, we stop all the development / test servers and simply start all the (virtual) production servers on the fail over server, stop development, focus all our attention on repairing the main server and when successful, switch back again To put it in money, this saves us easily a couple of thousands pounds because we don’t have to buy expensive development kit.
I have to say this wasn’t an easy task to set up but I finally got it working and it does gives me a little bit of geek pride because it puts us in line with two other major users of this technology: Google & Amazon 
Linq + Expression Blend 25 April 2008
Posted by Baz in Uncategorized.Tags: expression blend, LINQ
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This week I have been working on moving the address details away from organisation, volunteer and opportunities tables to a table which will only hold details about addresses. By using this method, organisation, volunteer and opportunities objects would have an ID of address which they refer to. The moving of address details will help us when we come to implementing some future user stories.
We finally got Expression Blend which we ordered a few weeks ago. Microsoft Expression Blend is Microsoft’s user interface design tool for creating rich graphical interfaces for web and desktop applications that blend the features of these two types of applications.
With Expression Blend we will be able to produce an interface which will make you say WOW! and in half the time it would take if you were using Visual Studio to design the interface.
Today I will be learning LINQ. LINQ is a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages using a syntax reminiscent of SQL.
From next week, will be off until 21st May. Until then adios!
Hello V-Base3! 23 April 2008
Posted by cherryeve in Uncategorized.Tags: Add new tag, team
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The journey of exploring the world of V-Base3 was started on the 18th April 2008. It was not my first day in YouthNet. There was a team lunch to welcome newcomers at 2PM. I came at noon and while waiting *hungry-mode* I was given a high level introduction to V-Base3 by Martin. Hopefully 80% of the explanation was processed and saved properly, thanks to the delicious curry from CurryLife Leaf.
My first impression was like “Hmmm… Spring, NHibernate, Accessibility feature, WPF, generated DB, SQL CE… wonder what is inside V-Base3.” I have always worked with SQL Enterprise edition 2000/2005 and have the luxury of using SQL profiler to debug, so it will be interesting to find out more what is offered on SQL CE and how light it is. The most exciting bit is WPF and Silverlight.
Also, on the Agile Scrum side, the practice is followed well by the team. I have always been a fan of agile development, this is the first time the implementation is consistent across all of the in-house projects *thumbs up*.
Finally, this is my third official day. The environment is setup, code build script works, created some user stories and sub-tasks, had a code walk-through of the current V-Base3 code, had an overview of WPF and plenty of technical resources (and things to keep developers not bored). It is not possible to achieve this without the help of the team, thanks guys!
(re)factor8 21 April 2008
Posted by Tracey in Uncategorized.Tags: iteration, recruitment, team
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iteration 8 is a refactoring/hardening iteration. no new business value gets added in this time; instead the team are laying the ground for the next lot of functionality to be added and tweaking the client to make it more stable.
we’re also inducting our new developer, sofia.
yes, you read that correctly - .net developer 3 is now in the house we’re not only extremely pleased to have her join us, but olivier has thoroughly enjoyed telling all the recruitment agencies that we’re no longer in need of their services.
when sofia’s had a chance to settle in a bit, hopefully she’ll do an introductory post.
assimilate! assimilate! 2 April 2008
Posted by Tracey in Uncategorized.Tags: team
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our numbers are growing… ben, the longest-standing member of youthnet’s web development team, is joining our project for the remainder of the year. ben will be working mainly on the back-end, including any changes to the existing do-it infrastructure that need to be made. to familiarise him with our development processes, he and olivier are currently tinkering with an online tool for administering v-base user accounts.
front-end and back-end are go!
p.s. this is the first time that the v-base and web development sides of youthnet have worked together on one project. joined-up work = good.
Screenreaders 31 March 2008
Posted by martin in Uncategorized.Tags: Accessibility, gui, JAWS, Narrator, Screen Reader
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Just tried our VBase 3 smart client with the Windows XP Narrator and a commercial equivalent called JAWS. According to the Wikipedia article on screen readers JAWS is quite a popular application (would love to hear Joe public’s opinion on that). I have not spent a great deal of time accessing either of these applications and so don’t want anyone to take my word on them as the definitive evaluation but I was surprised to find out that the Windows XP narrator application actually managed to read an entry on a WPF combo-box that the JAWS application failed to read. JAWS was much better on response and seemed to deal with menus in a more appropriate manner and also has features like a braille reader that I’m sure makes it more valuable to certain users than the XP narrator could ever hope to be. We will over the next few days be spending more time on accessibility and will have to as part of this investigate what Vista has to offer on the screen reader front. Hopefully Vista will have advanced from the XP narrator tool and will resolve some of the issues we currently have with accessibility for visually impaired users.
welcome back, camille 20 March 2008
Posted by Tracey in Uncategorized.Tags: team
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our ‘planification’ expert has returned from her travels in the southern hemisphere. understandably she’s a bit jet-lagged but it’s good to have her back in the bosom of our small (yet perfectly formed) v-base family
survey-itis 19 March 2008
Posted by Tracey in Uncategorized.Tags: requirements, research, surveys
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we’re currently undertaking some research with existing users of v-base, to find out how they would like to record details of policies and procedures against organisations and we’re doing this in the form of a mini-survey.
i’m always a bit apprehensive when sending out a survey – the voluntary sector is awash with surveys of all flavours and i know just how people feel when yet another email lands in your inbox, asking for your valuable input into something (hopefully) worthwhile. seems like everyone’s consulting everyone else and there’s a risk of survey-itis, where people just start to ignore these emails in the hope that others will respond with opinions similar to their own.
it’s a dilemma. we don’t want to pester our users, but if we don’t find out what they want, what chance do we have of developing something they will find useful? or the end result not being tailored only to the needs of the small group of people who can always be relied on to contribute? i can’t see another way around this – all i can do is make our surveys as short and easy to respond to as possible in the hope that this presents less of a barrier.
i’ll write another post shortly about this particular piece of research. it’s related to functionality that already exists in v-base 2.x which we’re thinking of approaching differently in version 3. like a lot of our planned enhancements, the seed for this one originated with someone who actually uses v-base, rather than just being something our development team dreamt up. i think i have the original email somewhere – i’ll see if i can find it.
Recruitment 19 March 2008
Posted by Olivier Van Acker in Uncategorized.Tags: developers, interviews, recruitment
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We’ve been recruiting right from the start of the project and have been fine tuning our recruitment process ever since. In the beginning we invited people in if their CV looked good. Soon it became very obvious that what is on paper is not always what you meet in person (This is a very big understatement). We interview with three people: me, the Product Owner (Tracey) and someone from Central Services, so a candidate who totally doesn’t live up to their CV wastes a lot of time. After several of these failures, Tracey gave me this little book: Smart and Gets Things Done. A very valuable book on how to recruit developers. One of the things I implemented straight away (the same day I got the book) was phone interviews, hooray! This is purely to see if a candidate lives up to their CV. Let me explain a bit more about this ‘phone interview filter’.
It consists of three parts:
- CV specific questions. I read the candidate’s CV and ask specific questions about technologies being mentioned. (E.g You have implemented cached program listings in XSLT/XML, how did you do that?) I’m careful not to turn this into a technical test, I just want to give the candidate enough room to talk ‘tech’ to me ;-P
- I present the candidate with a technical problem. This is to see how they approach a problem. Even if they don’t know the solution it’s good to see if they make an effort and how well they can reason. One candidate once bluntly said: ‘I haven’t got a clue how to do this’, followed by a silence. (Including my own silence) We skipped part 3 of the phone interview.
- Last but not least; I ask the candidate if they have questions about the project or YouthNet. This shows if they have a healthy interest, have themselves prepared and I think it’s good to have a two way interview.
With this ‘phone interview filter’ I’m able to decline about 80% of the CVs that get sent to me. A massive time saver. Also I’ve had some pleasant surprises where the CV was not very well written but the candidate made a good impression on the phone. So overall I can really recommend this, however I do keep in mind not to turn it into a full on interview, it’s just to see if the candidate lives up to his/her CV. The real test comes in our specially brewed ‘in house interview’ More about this in a later post.
Olivier
don’t forget to wipe 18 March 2008
Posted by Tracey in Uncategorized.Tags: agile, environment, tools
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just ordered some wipe-clean whiteboards. one of the downsides about working in an open-plan office next to a window is the lack of wall space. an agile project needs to surround itself with visual information… burn-down charts, ladders of story cards and preferably big white spaces for scrawling diagrams on etc etc.
one of the books i’m reading says:
“Try to have at least 24 linear feet of whiteboard space, magnetic if possible. You can never have too many whiteboards.”
personally i’d like a whole room (more about my ideal agile workspace later.)
we do have a great big mega whiteboard but it’s stuck to a wall in a different part of our offices. the new ones are free-standing, so we can wheel them around as needed.
mmmm wheelie whiteboards… how exciting is my life?
