Saturday, September 22, 2007

Talk about a word until it makes no sense.  Why would you do this?  This is much of what philosophy seems to consist of, attempting to reach the absolute definition of a word with zero ambiguity.  While a neat intellectual exercise, there exists a threshold where this ceases to be useful for most humans.  Typically most words can be defined in a short phrase.  This suffices to give us a mental picture of what a word is meant to convey.  In fact passing this mental threshold might be somewhat harmful.  There be dragons there. 

We can draw a parallel to programming or to program design.  Consider a database schema or a UML diagram of a painstakingly designed class hierarchy.  Each quantum of information neatly defined in terms of other types, just as a word1 is defined by other words.  Each word defined to the point of lowest ambiguity.  At least this is the intention of the designer if one follows the typical methodologies for such things.

However, is there a need to leave ambiguity in the system?  Can we equate ambiguity to abstraction?  On some level abstraction and ambiguity are linked. 

Consider the need the most organisms have for ambiguity in their perception of their environment.  Humans do night see all spectrums of light.  We do not hear all frequencies of sound.  The human eye cannot distinguish every possible shade of color.  If you say a restroom is for woman, your brain can picture the type of person that may enter that room.  The general class of woman is sufficient for the needs of blocking males from entering the females restroom.  Our brains have the ability to remove unneeded information so that we can concentrate on what is important.  

This is the crux of the issue.  This is abstraction.  Instead of dealing with the billions of women on the planet, we can deal with the one class of women.  We abstract away the complexity and gain ambiguity.  If we say that all women have long hair, we over specify the general case of women and lose the power of abstraction. 

What information is important in our system and how much do we really have to specify it.  Is it enough that we know that something is a series of characters forming a string?  Is a person’s name a series of fields like prefix, first name, middle name, last name, and another series of suffixes?  Or is it simply one string of characters?  

Let’s examine the first case.  In a large organization there is often a design or architecture team.  This team is typically obligated to define an organizations data.  The team most likely will tend to choose the multi field very explicit representation of a person’s name.  After all, what is there job but to minimize ambiguity and maximize specificity? 

In the second case a lone hacker with a deadline may decide that one long database field is enough to store the name.  This is most expedient and it gets the job done. 

Why does the lone hacker’s system survive longer and cause fewer problems?  Consider the first case again.  Most likely we will have to define a suffix table where every known suffix (Jr, Sr, MD, CPA) is defined.  After all a user must now choose this from a dropdown.  Also the prefix must be entered.  We will need another table to define these.  What happens with a person who has two middle names?  Do we define another column?

It appears that even in the simplest data point definition we have run head first into mushrooming complexity.  How long do you think the design meetings will take JUST to determine how to define a name?  I’ve been in on this and it can take a surprisingly long.

The lone hacker has written most of his system by the time the committee has determine the proper representation of each data point in the system. 

The fact is that ambiguity or rather the ability to handle ambiguity is a feature of a system not a flaw.  Many times the ability to handle ambiguous data from a user or external system saves a monumental amount of redesign and rework.  An example would be a company that decides to open a foreign branch and now must handle names in a different format.  Do we need to redesign our system or does it just work?

A caveat here is the interfacing to other (broken) systems that require the data to be split into small pieces and fed in.  A partners system requires first and last names.  Is this a problem?

It can be.  One solution is to parse the name field.  Ninety percent of the names will probably be first and last name only.  This is because most users are lazy and only want to enter the minimum amount of data.  Some self absorbed types are going to enter every credential in the list including their Boy Scout merit badges.  Now we may have to kick back this data to a human to look and correct.  Last I checked data entry was cheap, programming was expensive.  A great solution?  Maybe, maybe not.  How much money did your design team burn by arguing over what should be in the prefix and suffix table? 

In the age of search, ambiguity becomes more useful.  If we can search on any field in the database than I no longer have to use last name to organize a list of people.  Searching for them may work much better.  Or it may not and you find that you want a separate first and last name field.  

Of course if your requirements call for separate fields because they must be fed to another legacy system, then by all means specify two fields.  You have a valid reason to do so this increases the coherency of the system.   My point is about over specification in the absence of requirements.  

In the absence of requirements, don’t over specify.  Creating unneeded complexity in a system does not benefit anyone.  Ambiguity, as a facet of abstraction, provides the designer a way to deal with complexity or at least to mitigate it.

 

1-In fact languages like Forth or Factor call the smallest unit of execution a “word.”  The word in such a language is equivalent to a function in the more “mainstream” languages.

Saturday, September 22, 2007 9:52:04 PM (Central Standard Time, UTC-06:00)  #    Comments [0]
    Discuss how the addition of attributes can be seen as adding adverbs or adjectives to a language. 

Saturday, September 22, 2007 8:51:39 PM (Central Standard Time, UTC-06:00)  #    Comments [0]
 Thursday, July 19, 2007

Joel on Software's admin dude wrote a post about how they are doing db backups. 

http://www.michaelgorsuch.org/wordpress/2007/07/11/some-times-you-have-to-roll-your-own/

Funny thing is that this is how all databases fundamentally perform backups.  Just makes me think that once you get X years under your belt you come to the conclusion that you've seen it / know it all.  Fundamentally, this stuff is simple, the problem comes into play when MS (or vendor of choice) tries to layer multiple extra layers of shite on top of a simple concept.

Html, javascript, css are easy (compared to multi-threaded servers and C++).  ASP.NET makes them much more complicated then the have to be.  I'm currently in the process of removing all of the ASP.NET AJAX CRAZY framework out of the whatsyour20.com as it's just too damned complicated for what you get.  Also I think the ASP.NET page life cycle is ridiculous.  We stopped teaching ASP.NET for web development at the college I used to teach at because it was just too hard for students to figure out.  Ironically, MS made ASP.NET follow the desktop paradigm to get the Windows Forms dudes (like myself) to buy in, which caused ASP.NET to become almost incomprehensible for those that wanted to learn web development without having any desktop experience. 

There is a reason PHP and MySQL are so popular.  Simplicity has a place and that place is HUUUUUGE.  It's a big house on the hill overlooking the lake with a great view. 

The point of this rant is that sometimes we make things so complex by trying to make them simple.  Instead are we perhaps better off if we let the complexity stay were it needs too. 

ASP.NET missed being one of the best pieces of software ever designed.  Why?  Page lifecycle (why must i figure out if i need init, load, pre init, pre load after load, after init, and the if (postback == false) { madness).  The dirty little secret about ASP.NET is that nobody needs a freakin' data grid!  They are completely useless.  Html tables are easy to make.  Grids are ridiculous and bloated and don't support Ajax worth a damn. 

Why I'm at it I should rant about how SQL Server 2005 leaves out features already in 2000.  But this post is getting too long as it is.

ASP.NET needs a sane alternative implementation that works with the web instead of against it.

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Thursday, July 19, 2007 9:52:46 PM (Central Standard Time, UTC-06:00)  #    Comments [1]
 Wednesday, May 23, 2007
There is a discussion over at Scott Hanselman's site about URL Rewriting in ASP.NET.  I found a similar article about URL Rewriting in ASP.NET on Coding Horror


Synopsis:

Here is a brief synopsis of the problem.  In order to have an http module or handler take care of your url rewriting you must have all requests sent to aspnet_isapi.dll via application extension mapping in IIS 6.

Here is an example:

I want http://whatyour20.com/modules/view-location.aspx?locid=1234

to instead look like:

http://whatyour20.com/locations/yellowstone-national-park/

I do this for several reasons.  The number one reason is SEO.  We want google to give google a good idea of what this page is about.  Obviously the latter url does the much better.  It also gives the users an idea of what the link is about.  Number two, it makes our links hackable.  Number 3, it makes our links more aesthetically pleasing.  I think that is very important.  If I see a url that is meant for people instead of machines, I know the web site creator took some time to dot every i and cross every t.  Number four is the less likely option that I will switch technologies and I don't want to lose all my links and there associated page rank if I switch to a new technology or if Microsoft changes thier extension in the future when the next great thing comes out (Silverlight Foundation Server Pages Advanced with SteelRuby, LOL). 

At whatsyour20.com we use UrlRewritingNet.UrlRewrite to handle all url rewriting duties.  UrlRewrite is an asp.net http module that can rewrite any incoming url and it can handle redirects (301, 302).  This works great but it doesn't get rid of the aspx extension by itself.  In fact no http module or handler can do that because iis uses the file extension to determine which program should handle the request. 

So we need to have IIS route all requests for the domain (http://whatsyour20.com) to the aspnet_isapi.dll as stated above.  The problem with this is that now ALL request will go through asp.net.  We may not need this for all requests.  In fact this can be a problem as it can hurt performance.  I've seen the a claim of 30% performance decrease someplace but I don't remember where right now.  However, it's safe to assume that routing static content through asp.net is just not the best solution.

Solution:

The solution?  After the background information we are finally at the payoff.  This is how we get the goodness of using asp.net url rewriting via http modules and the associated debugging and high level of control this brings us WITHOUT the downside of routing static content through asp.net. 

We access all the static content via a sub-domain.  We use static.whatsyour20.com to server all the static content on the site (Right now this is mostly images).  This is very easy to accomplish.  You simply create another web site in IIS, with the path to the same location as your main domain but using the sub domain.  On this domain you DO NOT route the requests to asp.net.  So on this sub domain all content is handled by IIS because it is static.  You could even take that a step farther and put it on a separate server or use another web server that is optimized for static content. 

Our solution works in a share hosting environment because usually you can set up sub domains on shared hosting.  Also you can usually get all requests routed to asp.net if you put in a ticket and simply ask for it.

A nice side effect of using sub domains is improved performance on the client side.  By increasing the number of hostnames (within reason) we can increase the speed at which the page loads.

Here are a few reference articles on multiple domains names to speed up downloads:
http://yuiblog.com/blog/2007/04/11/performance-research-part-4/
http://www.ajaxperformance.com/?p=33
http://www.die.net/musings/page_load_time/

Conclusion:

Using the presented solution we get a urlrewriting solution that is easy to use and configure (all configuration in web.config), transfers easily between hosting providers (again its all provided by asp.net and web.config) and it improves performance.  I'm still looking for any possible downsides.  Please let me know if you know of any.


Wednesday, May 23, 2007 7:29:14 PM (Central Standard Time, UTC-06:00)  #    Comments [1]
 Wednesday, January 03, 2007
How many times has your database servers hard drives filled up and you want to find the culprit?  Probably not many but for me it happens all the time.  Here is a simple command to get a list of all sql server databases and their file size:

use master
go

exec sp_databases
go

Need to find out where the files are on disk?

SELECT [name] [Database], [filename] [File Path]
FROM master..sysdatabases

Wednesday, January 03, 2007 9:34:00 AM (Central Standard Time, UTC-06:00)  #    Comments [0]
 Wednesday, December 27, 2006

If you have been struggling like me to make your sites XHMTL compliant you realize that it’s not an easy task.  Most of the changes are straight forward if you have a validation tool.  I code a lot of sites in Visual Studio 2005 and it will complain like crazy if you have invalid XHTML.  Hence I try not to write invalid XHMTL because I hate errors and warnings and will compulsively try to make my pages as valid as humanly possible.

 

One of the areas where I’ve had the most trouble with this is create bookmarks with anchor tags.  Most of the examples I’ve seen use the name tag on an anchor so that you can link to it using something like http://example.com/test/#somebookmark.  I think this is an underused feature of html as it makes navigation much better and faster, plus it is much easier to link into a page at just the right point with something like this.

 

When using XHTML you should not use the name attribute as it has been deprecated.  Instead you should use the handy id attribute.  The id attribute will work exactly the same way and has the benefit of being compliant.  Plus you get additional validation of making sure each element has a distinct id.  This was a problem with some sites I’ve seen that use name.  I see the same name used all over the place.  This makes linking to the element somewhat difficult and error prone.

 

On a related note, did you know that most modern browsers can link directly to any element that has a valid id attribute?  This is very handy as you want have to include anchor tags all over you html just to get convenient linking.

 

Bad:  <a name="bookmarkid">Test</a>

Better: <a id="bookmarkid">Test</a>

Best: <p id="bookmarkid">the element i actually want bookmarked can be linked to directly</p>

Wednesday, December 27, 2006 1:47:20 PM (Central Standard Time, UTC-06:00)  #    Comments [0]
 Friday, November 24, 2006
I've got a few machines at home and I want to use Remote Desktop to connect to them when I'm out and about.  Well one is easy enough to set up if it is either directly connected to the internet (possibly a bad idea) or if you have a wireless router with a firewall and other management features (much more secure).  I have the latter and I set up a rule to forward remote desktop traffic on TCP port 3389 to my main desktop.  But I also have a server I would like to get to.  No problem you just need to change the port that Remote Desktop uses in the registry.  Just go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp and find the PortNumber entry and change it to the port you want.  Make sure you edit it as a decimal by choosing the decimal base.

Here is an easy article on setting up multiple machines for Remote Desktop access.

Check out the article for a lot more info.

Friday, November 24, 2006 8:57:20 PM (Central Standard Time, UTC-06:00)  #    Comments [0]
Here's a code tidbit to enable the service broker in SQL Server 2005.  This needs to be running for caching to work in ASP.NET.

IF (SELECT is_broker_enabled
  FROM sys.databases
  WHERE database_id = DB_ID()) = 0
    ALTER DATABASE yourdatabasenamehere
    SET ENABLE_BROKER
    WITH ROLLBACK IMMEDIATE

The if statement checks to see if the broker is already running.  If it is not then it attempts to enable it.  The WITH statement will rollback any other pending transactions that may be blocking this transactions.  This is important because if you run this statement without WITH ROLLBACK IMMEDIATE then it may seem that the batch will not complete.  Again, this is because other transactions or services like SQL Server Agent may be blocking.

Friday, November 24, 2006 8:41:50 PM (Central Standard Time, UTC-06:00)  #    Comments [0]
 Sunday, November 19, 2006

One argument script pimps use frequently is that it doesn’t matter what tools a contractor uses to build a house as long as the finished product is the same.

The problem with this argument is that the premise and the analogy are flawed.  Comparing the language to the tools is not quite accurate.  The language is more aptly compared to the building materials used instead of the tools.  The tools would instead include things like the IDE.  With the analogy corrected we now see that the choice of building material is very important.  Using 2x4's instead 2x6's will have a big impact on insulation properties (thicker wall cavities) and cost. 

Is this important?  Absolutely!  

Unfortunately, too many scripting language fans (script pimps) make the same flawed analogy in order to justify the use of their pet language instead of a higher performance language like C++ (or C#, Java, etc).  Scripting languages like Ruby are slower then compiled languages.  Also their nature precludes them from having good IDE support.  This is because much of the meaning (context) can’t be derived until runtime so things like IntelliSense become difficult if not impossible to implement. 

Following the scripter’s analysis we are supposed to assume that scripting languages allow faster construction which I would say is another falsehood.  Yes, some contractors might be able to cut wood just as fast with a handsaw but most want to use as much automation as possible.  Hence, table saws, compound miter saws with laser guides, etc.  These automation tools are closer to Visual Studio than VIM. 

In my experience with Ruby (among other languages) I found that the resulting programs were usually slower, which a scripting language will be by its nature.  I also found that the emperor wears no clothes!  Shockingly, developing in a scripting language is slower because of the lack of automation tools.  Example, try to find all references to variable in a Ruby on Rails project.  Now try the same thing in a C# project using Visual Studio.  In Visual Studio it’s a right click and “Find All References”.  In VIM you could search for the references but you don’t have any support for context.  You don’t know that is the only reference to that variable.  You are using a handsaw instead of the best tools available.

I'm sorry but reality demands that 1 = 1 and slower is slower and speed is important.

Sunday, November 19, 2006 9:53:49 AM (Central Standard Time, UTC-06:00)  #    Comments [0]
 Wednesday, November 15, 2006
As you may have noticed, I'm on a performance kick as of late.  Here's one more tip for you.  Compressing / Minimizing / Shrinking your JavaScript files can decrease download times.  Putting your scripts together in one file will also help performance.  Here's a good article on reducing page load times from a Google engineer.  This article is the source for most of this wisdom.

So armed with this new knowledge I went in search of some pre-shrunk versions of the Prototype and Scriptaculous JavaScript Libraries.  This is what I found.  I still need to test the library but it seems promising.  I will keep you posted.

Wednesday, November 15, 2006 11:44:42 PM (Central Standard Time, UTC-06:00)  #    Comments [0]
Ok URL Rewriting is good.  I won't go into the reasons why but if your searching for it then you already know you want it. 

If you followed the standard progression you probably started with this MSDN article on URL Rewriting.  This implementation works fairly well in ASP.NET 1.x.  However, I've run into problems using this implementation in ASP.NET 2.0 with output caching.  For some reason it breaks output caching.

So what is the solution?

Well I'm glad you asked.  I've found a solution that works quite well with ASP.NET 2.0 and output caching.  The UrlRewritingNet.UrlRewrite assembly provides all the features of the original URL Rewriter mentioned above but also fixes the problems with output caching plus adds some interesting features like redirecting and programmatic access to the rewrite rules at runtime (say that ten times fast!). 

I'm currently using this on http://www.whatsyour20.com and I must say it works quite well.  I also like the fact that it is an active project and it even has a bug tracker system.  There is also a forum for this project.  That's always a good sign.

Enjoy!

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Wednesday, November 15, 2006 10:20:11 PM (Central Standard Time, UTC-06:00)  #    Comments [0]
What do you do when you want HTTP Compression to speed up your site but you are using ASP.NET (1.x or 2.0) in a hosted environment?

You get HttpCompress from www.blowery.org/code/httpcompressionmodule.html. This is a module that sits inline and handles compression of your .aspx pages and any other mime type that may be handled by ASP.NET.  This is a pretty good work around if you don't have permission to IIS to enable HTTP Compression there.  Of course that would be a better solution but many hosters won't enable it because of the possible CPU consumption issues.  Oh well, get around them by implementing your own solution!

I know dasBlog uses it in the 1.9.x version.  WhatsYour20.com is also using it at this time.

It's been around for awhile, it's configurable and it's easy to use. 

Give it a try and speed up your site today!

One caveat is testing it using ASP.NET Development Server.  Check out the link for more info.

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Wednesday, November 15, 2006 10:10:06 PM (Central Standard Time, UTC-06:00)  #    Comments [0]