NIH

This is the theoretical (worst-case scenario) performance requirement:

As existing frameworks and 3rd party tools don't match these requirements, new frameworks will be developed.

After spending many men-months on developing new frameworks (even before the development of the application itself) this is the application's performance:  

Eventually the application is shipped, and customers are satisfied with the performance.

However, this is the average case performance requirement: 

(NIH = "not invented here", a common syndrome in the software industry leading to spending resources to create new tools instead of using existing ones)

Using Bluetooth to build a home network

Usually I use my desktop computer to surf the web, but recently I decided I want to be able to also use my mobile computer at home, and this require network access.

At first I inquired about using WIFI access, but there is a major downside to this for me: I don't want the router to broadcast a signal while I don't need it (both to save energy and to avoid an extra EM field around the house).

So I thought about using Bluetooth:

• Easy to turn on and off
• Cheap (50-100nis for a BT adapter for my desktop)

I usually use the mobile computer about 6-7 meters from my desktop, through a plaster wall, so that's well within the specifications. I now manage to get 150kb per second download speed, and I'm writing this post from the laptop.

I had few problems establishing the internet sharing, but thanks to the good manager of the Israeli broadband forum at Tapuz I found an excellent guidance document for configuring ICS.

Highly recommended, even for non-Hebrew speakers (as there are screen-shots):

1. Setting the server for WinXP (desktop)
2. Setting the client for WinXP (laptop)

מתחילים בליסינג, ממשיכים לקרנות השתלמות

אין אלוהים מבלעדי אייפון וסטיב ג'ובס משיחו

WCF UDP multicast channel performance

After creating a custom UDP mulitcast channel using WCF I ran some tests. I used this sample data contract class:

        string Name
        string Description
        ushort Id
        double X
        double Y
        double VX
        double VY
        uint Flags
        DateTime CreatedTime
        DateTime UpdateTime

Benchmark Results: 

• Max amount of sent objects per second using 100mbit hub (using Intel 3Ghz HT CPU - not dual core): 46000
• CPU load during peak sending - 15-25%
• Effect of zip encoding - 50% less bandwidth with random values (probably 60-70% reduction in a real-world scenario)
• Sending 10000 objects per second - no significant CPU load (3-5% for both apps), GC load - less than 0.5%

Using UDP multicast channel in WCF

I recently needed to build a WCF UDP application as a proof of concept.

Sadly UDP is not among the channels bundled with the WCF, so I needed to put up something myself:

• Downloaded the WCF technology samples, containing a UDP transport demo (there used to be a sample at the netfx3 site, but it's long-gone) 
• Copied the UDP transport sample project (from the folder \Extensibility\Transport\Udp\Cs\UdpTransport) into my solution
• Added the extensions section to the config file to add the UDP support (config file coming up soon)
• Added multicast="true" switch to the binding section
• The address prefix is hardcoded in the UdpChannelHelpers.cs file, so if you like something other than "soap.udp" you need to edit the "Scheme" constant.
• Since UDP is limited by a 64kb packet size, you may also want to use the GZipEncoder (found in \Extensibility\MessageEncoder\Compression\CS\GZipEncoder)

You need to remember that since this is multicast, the client is the one doing the transmitting while the service is a only a passive listener.

Client configuration:

<configuration>
    <system.serviceModel>

      <extensions>
        <bindingElementExtensions>
          <add name="udpTransport" type="Microsoft.ServiceModel.Samples.UdpTransportElement, UdpTransport" />
        </bindingElementExtensions>
        <bindingExtensions>
          <add name="sampleProfileUdpBinding" type="Microsoft.ServiceModel.Samples.SampleProfileUdpBindingCollectionElement, UdpTransport" />
        </bindingExtensions>
      </extensions>

      <client>
        <endpoint address="net.udp://225.225.0.1:2222/Observer/"
          binding="customBinding"
          bindingConfiguration="DatagramServer" contract="MyNamespace.IObserver"
          name="ClientService" />
      </client>

      <bindings>
        <customBinding>
          <binding name="DatagramServer">
            <binaryMessageEncoding></binaryMessageEncoding>
            <udpTransport multicast="true" />
          </binding>
        </customBinding>
      </bindings>

    </system.serviceModel>
</configuration>

Service configuration:

<configuration>
    <system.serviceModel>

      <extensions>
        <bindingElementExtensions>
          <add name="udpTransport" type="Microsoft.ServiceModel.Samples.UdpTransportElement, UdpTransport" />
        </bindingElementExtensions>
        <bindingExtensions>
          <add name="sampleProfileUdpBinding" type="Microsoft.ServiceModel.Samples.SampleProfileUdpBindingCollectionElement, UdpTransport" />
        </bindingExtensions>
      </extensions>
   
      <services>
            <service name="ObserverService.Observer">
              <endpoint address="net.udp://225.225.0.1:2222/Observer/"
                  binding="customBinding"
                  bindingConfiguration="DatagramServer"
                  contract="MyNamespace.IObserver" />
            </service>
       </services>
      <bindings>
        <customBinding>
          <binding name="DatagramServer">
            <binaryMessageEncoding></binaryMessageEncoding>
            <udpTransport multicast="true" />
          </binding>
        </customBinding>
      </bindings>
    </system.serviceModel>
 
</configuration>

Performance improvement from switching to Framework 2.0

The application I'm working on is a C4I, GIS based application, originally written in framework 1.1.

Recently we did several tests to prove the improvements derived from upgrading to framework 2.0 (or 3.0) without doing major changes in the base code. The performance improvement focus was on switching to Generics for collections containing value types.

Possible pitfalls - mostly the usage of Hashtable and other 1.1 collections, which tend to return NULL when the key is not found. Unlike them, the Dictionary class and similar generic collections tend to throw exceptions if the key is not found. This requires adding calls to the ContainsKey method to prevent these exceptions. Nothing complicated, but a lot of manual labour.

Performance improvements (also with some minor refactoring):

• CPU usage in heavy-load-scenarios was reduced by 10-20%
• Time in GC (as measured by perfmon) was reduced to half of the previous value

Blame Canada

Justin-Josef Angel is leaving Israel and moving to Canada.

For the occasion I decided to republish Eran's comment to a post I wrote some months ago:

Times have changed,

our kids are getting worse,

From sending simple text messages they turned vampire bytes and alcohol shots

Should we blame the government?

Or blame social networking?

Or should we blame the images on TV?

No,blame Canada, blame Canada

With all their beady little eyes have packed their heads so full of lies,

blame Canada, blame Canada,

we need to form a full assault, its Canada's fault