AppFabric Goes South(ampton)

(Very!) Belated thanks to the good developers of the NxtGen user group in Southampton for having me down last week to give my Developers Guide to Distributed Caching with Windows Server AppFabric talk. Despite a horrible journey round the M25, I had a really good time - I felt the session went well, the technology didn't let me down, and there were some really good and interesting discussions during the session and afterwards in the pub. It was also good to put a few faces to Twitter names!

AppFabric Goes to Ireland

Last week I gave my Distributed Caching with Windows Server Appfabric talk at EpiCenter, the Irish Software Show, at Trinity College in Dublin. My audience was a little, ahem, disappointing, particularly in the week that AppFabric was officially announced and released, since I only had one audience member, Mark Needham of Thoughtworks, who was presenting in the afternoon. I also had technical troubles with AppFabric again - clearly in a previous life I seriously pissed off the demo gods. I've now torn down my AppFabric demo infrastructure to rebuild it - this also gives me a chance to recompile my demos with the release version of AppFabric - I've been using the Release Candidate.

My slides from EpiCenter can be seen on Slideshare, and my demo code is downloadable here.

The Irish Software Show

It's the Irish Software Show this week! There are 80 sessions taking place from top speakers including Craig Murphy, Jon Skeet, Alan Dean and many others. And also, ahem, me.

I'm doing my session on Distributed Caching with Windows Server AppFabric tomorrow, Wednesday 9th June. I shall also be attempting to whip the crowd into a frenzy before Jon Skeet does his first session - yes, I'm Jon Skeet's warm-up man!

If you haven't got tickets for the show yet, it's not too late! And even better, the organisers have very kindly allocated some concession tickets to me: if you go to my page on the EpiCenter website, you can get up to €90 off the price of your ticket! And I'll see you tomorrow!

AppFabric Goes North!

Thanks to NEBytes for having me up to speak last night (and thanks to Andy (and Tammy :-) ) for putting me up). I ran my AppFabric distributed caching session, and for the first time nothing broke! Lots of performance problems though, caused by trying to run too many VMs on not enough memory. I think when I get home I'll review my demos: I want to run them all in one VS project to make it easier to swap between them as I'll just be able to run up one Cassini instance that'll contain all the demos. I was also thinking last night I might change the Regions/tagging demo so I get the objects from the database as required and then cache them in a lazy style. Watch this space.

I missed the first half of Jonathan Noble's session on Powershell 2.0, but I was quite impressed with what I did see. My use of Powershell can be described as 'fledgling' at best (even though it's used in managing AppFabric clusters and caches), so it was instructive to see it really put through it's paces. The remoting tools built into Powershell 2.0 look particularly impressive, it's made me think about how we manage our web servers at work and whether we should be using Powershell from our desktops instead of RDPing onto the servers and then using the IIS MMC.

I'd have liked a bit more time to look round Newcastle as it's somewhere I've never visited - maybe next time. I did get to drive past the Angel of the North, which was disappointingly somewhat less impressive than I'd anticipated. And this morning on the way back I got to see (if only on the horizon) the Middlesborough Transporter Bridge! (Thanks for the A19 tip Andy!)

A Developer's Guide To Velocity on tour!

Following on from Liam's recent tour dates blog,I thought I should do something similar...

First of all I need to offer belated thanks to NxtGen Manchester for having me up to speak in January. I had a good time even though something went wonky in my VMs while I was running my demos that morning which meant I couldn't run the demos in the evening. I hope everyone still got an appreciation of the capabilities of Velocity.

I'm running this session again at Edge UG at Microsoft in London on 17th March - visit http://edgeug.net to sign up. I may be running it at DDD Scotland if I've been voted in. Subject to agreement on dates it'll be at NxtGen Southampton in June. I've also been talking to NxtGen Cambridge and NEBytes about doing it for them over the summer.

UPDATE: Well I didn't get voted in for DDD Scotland, but there'll be another opportunity to vote for me at DDD Southwest.And I now have a confirmed date for NxtGen Southampton - 24th June.

@philpursglove is in Demo Hell

Last Tuesday I took my new session on Velocity to the NxtGen User Group at Oxford, having responded to Barry's plea for a speaker. And I had a bit of a 'mare. In fact, a lot of a 'mare.

I knew I was in trouble when I fired up my laptop and the Velocity Powershell console showed an error immediately. So I tried to fix it by uninstalling and reinstalling only to discover that if you have no network connection Velocity will not install. At all. It makes no difference whether you're using a network share on the local machine to store the cluster config, or trying to store it in a SQL database on the local machine - no network, no cache.

So I'd like to thank everyone for listening and offering suggestions as to how I might have got things working faster. I've put my slides up at http://philippursglove.com/velocity , but I'm doing a bit more work on the demos, I'll put them up later this week.

VBUG London

My thanks to VBUG London for allowing me to speak on Tuesday night, and also to Sam and Keith for organising it. I hope everyone found the session useful - I really enjoyed it. And the pizza was good too :-)

I've updated the slides and code samples at http://www.philippursglove.com/ScalableASPNET - the Velocity demo is now updated to Velocity CTP3. I re-ran the Velocity demo yesterday morning and it worked perfectly. I suspect that it failed on Tuesday as my laptop couldn't contact a domain controller to verify my admin credentials :-(

ASP.NET Scalability at WebDD

Thanks to everyone who attended my session on ASP.NET scalability at WebDD today - I hope you all found it useful. I got to the end of the section on caching, which is more or less the first half, and realised I had ten minutes left for the entire second half, so apologies for having to race through the rest of the slides. If anyone has any questions please feel free to post them in the comments here and I'll answer them.

I had a few questions afterwards over coffee, which were:
Q) Output Caching. Can you VaryBy things other than elements in the QueryString?
A) Yes, there are a range of VaryBy options: VaryByContentEncoding, VaryByControl, VaryByHeader, and VaryByCustom. In each case ultimately it boils down to a string. There's a discussion of all these options on MSDN, but basically VaryByContentEncoding's probably not going to help you too much since this looks at what encodings your browser can accept e.g. compressed content (and remember that I mentioned all the current browsers (and previous generation browsers) can accept compressed content). VaryByHeader looks at a semi-colon seperated list of HTTP headers. VaryByControl looks at the controls declared inside a UserControl. VaryByCustom is perhaps the most interesting as it allows you to roll your own scheme by implementing GetVaryByCustomString in your Global.asax file, or if you set it to 'browser' it caches page instances based on the browser name and major version.

Q) Is there a reason not to use VaryByParam=*?
A) VaryByParam=* will cache pages on all combinations of elements in the QueryString - I can only tell you what it does, it's up to you to decide whether this facility is going to fit into your application or not.

Q) Can you cache objects for longer than 20 minutes?
A) Yes. If you use sliding expiration, it takes a System.TimeSpan object. TimeSpan has three constructors - I used the hours/minutes/seconds constructor, but there's nothing to stop you using the second constructor which adds a days parameter onto the constructor. Bear in mind, however, that doing that means you're sacrificing that much memory on your server for that length of time. As with so many things in scalability, it's a trade-off...

Q) Do you need command-line access to your server to enable a SQL database for SQLCacheDependencies?
A) No. There's two options here: one is to keep in mind that the ASPNET_REGSQL command-line tool takes a server name from the -S parameter - this can be any SQL server that is on your network, you don't have to run the tool locally to the server you're enabling.
The second option is to use the SqlCacheDependencyAdmin static class, which gives you the ability to programmatically enable and disable databases and tables for cache dependencies.

Speaking at WebDD

I had an email from Phil Winstanley overnight to say that my talk on writing scalable ASP.NET has been accepted for WebDD at Reading on 18th April.

I'm looking forward to running it again, this'll be the third outing. Maybe Barry'll get to it this time...

Update: Delegate registration is now open. Book early to avoid disappointment.

Thanks to NxtGen Oxford

Thanks to everyone at NxtGen Oxford who came to see my ASP.NET scalability presentation last night. The code and slides are available for you to download at http://www.philippursglove.com/ScalableASPNET. I haven't had chance yet to work out why the SqlCacheDependency demo didn't behave, I'll look at this later on today and update this blog entry when I've worked it out! Feel free to email me at phil@philippursglove.com or comment here if there are things that need more explanation or you just want to discuss something.

Update: I just figured out why the aspnet_regsql command-line was failing when I tried to enable my Northwind database for caching. I hibernated my laptop when I left the office on Tuesday afternoon, on Tuesday evening when I switched it back on it couldn't contact our domain. So when I tried to run aspnet_regsql with the '-E' switch for integrated authentication, I couldn't be authenticated against our domain and consequently SQL Server's security (correctly) wouldn't let me do anything. If I'd instead used the '-U' and '-P' switches with an administrator username and password it would have worked.

WebDD

I was pleased to see a tweet from Phil Winstanley yesterday announcing that there will be another WebDD this year. I went to the one in 2007 and had a fab time.

Once I've come up with some words about myself I'll be submitting my scalability in ASP.NET session. I'm also trying to write a session on scalability with Velocity - maybe this'll be the kick I need...