Archive for April, 2008

4 Gig, Windows XP and Too Many Windows

Sunday, April 27th, 2008

I have a Q6600 system (quad core) with 4 gig of memory (3.5 gig usable), Windows XP 32 bit and could not understand why I had trouble opening more than 10 or 20 IE windows without  weird issues in the desktop.  I’d be missing portions of the UI, couldn’t bring up windows and generally things slowed to a crawl. How could that be with lots of free VM as reported by the task manager?

Well the answer is a tuning parameter that limits how much memory a given desktop application can utilize. This blog post from 2004 describes the problem in detail and has the fix! Windows XP flakiness – solved

I set my SharedSection value to 8096 and I can now open 30 IE windows with no issues. This has bugged me for months and the problem was forming a proper Google search to find this post. Thank you Kevin Dente!

Oh My – Lost Was Awesome

Friday, April 25th, 2008

Janna and I watched Lost last night and we were both blown away. Ben is a "badass" and Michael Emmerson is just an amazing actor to watch. I’m listening to the Jay and Jack Lost podcast on my normal morning walk.

Charter To Offer 16MB /2 MB in St. Louis

Friday, April 18th, 2008

Not available yet but this link implies that Charter will offer this in St. Louis at some point:

Charter Thread

Charter and Google Fixed in St. Louis?

Monday, April 7th, 2008

I haven’t change my DNS back to Charter’s servers but a post in this thread seems to indicate that the problem has been resolved.  http://www.dslreports.com/forum/r20199048-Charter-Google-Chicago~start=20

OpenDNS seems to be working well for me and I must might leave it set up for a few days to see if I continue to like it.

Found This Blog Entry: Agile Ajax: Ajax Testing: Doubling Down with Selenium and JMeter

Monday, April 7th, 2008

Agile Ajax: Ajax Testing: Doubling Down with Selenium and JMeter

This could be a solution for our automated testing issues.  Use Selenium IDE to record and test and then play back the test while JMeter is watching your HTTP traffic.

Google and Charter – DNS Issues in St. Louis – Is it Charter’s DNS or Routing?

Monday, April 7th, 2008

Over the last week I’ve had trouble hitting Google with the address www.google.com.  The following is what I see:

image

I decided to use OpenDNS as indicated below. It seemed to work at first but then an hour later I’m having the problem again – the following solution actually may not work. Upon reviewing the thread below, it seems the issue is routing of some sort and pointing at OpenDNS may not fix the problem. At this point the only fix seems to be to use the one of Google’s numeric IP address such as 64.233.167.99.

It appears to be a problem with Charter’s DNS as seen in this thread:

Google and Charter DNS Thread – Broadband Reports

Hitting the IP address 64.233.167.99 seems to work fine.  Some solutions:

Use a host table entry for www.google.com to the IP 64.233.167.99 or point your DNS to Open DNS:

208.67.222.222
208.67.220.220

It is definitely annoying and others have reported that Charter support does not accept responsibility for this issue.

My Microcontroller is now Colossus – The Forbin Project

Sunday, April 6th, 2008

I was working today on my little gadget I designed last year.  On its first test run last December, it was dropped on the “on/off” switch and broke.  The test trials were very short and the project was shipped back to me for what I thought was an easy fix. Well, the switch is fixed, but now the AVR decided to stop communicating with the JTAG interface so I can’t program the beast anymore.  Unfortunately, I didn’t design a ISP interface onto the board so I have to tack wire wrap wires  to the 4 lines on the Mega128 and hook up my ISP to try to get the JTAG fuse set to re-enable the interface.  Well that doesn’t work either – the debug interface says the chip can’t go into program mode.  But I checked some pins on the micro with my scope and it seems to be very happy doing something – sending data on the serial interface and flipping bits on the I2C interface like crazy.  However the display doesn’t work and I can’t get a firmware boot to load either.

Well that reminded me of Colossus the Forbin Project – my favorite movie when I was 14 years old and I had to pop the DVD into the PS3.  Darn old Collossus decided to do its own thing also.  Only – it can launch ICBMS and my little ATMEL Colossus can only annoy me.

Here’s the info on this little known movie:

Colossus: The Forbin Project

Released: 1970

Go to IMDb page

Information © IMDb.com

Colossus: The Forbin Project

Eric Braeden, Gordon Pinsent, Leonid Rostoff, Willard Sage, Martin E. Brooks, Dolph Sweet,

An artificially intelligent supercomputer is developed and activated, only to reveal that it has a sinister agenda of its own.

Our Problem with the Selenium IDE and AJAX

Thursday, April 3rd, 2008

We have an application that uses quite a bit of Ajax and this caused problems in recording tests using the Selenium IDE. Each test step was recorded successfully, but because there are web services calls firing in the background on the client (the Ajax stuff), a playback would fail immediately. The fix in general is to use Javascript to check for a completion flag of some sort, but the IDE did not have a provision for inserting code automatically or to delay each test step.  This limited the ability to rerun a recorded test when mistakes are made during the recording process. I’ve been working (with other engineers) on modifying the Selenium IDE code to allow the automatic insertion of Ajax rendering complete Javascript code. However, the latest version of the IDE in SVN has a slow-down control now and that seems to work like a champ on our app.  It allows you to slow the playback down to something that approximates human speed and our app now seems to be happy as we record and then play back.  Thanks to the Selenium IDE developer Shinya Kasatani for this great addition.

I still plan to add a switch to allow specified Javascript to be executed automatically when the Selense plays back – to allow a check for a "render complete" flag that we have in our Javascript.

Functionality Verification, Regression, Stability, and Load Performance Testing of Ajax Web Sites

Wednesday, April 2nd, 2008

As part of stuff that I’m working on, I’m surveying various tools to test new web applications that my group is working on. There are some interesting open source tools that can do some amazing things and I’m collecting a few of the links to docs and videos I’ve seen as part of my survey. I’ll update this post with info as I find it.

We (our customers) currently live in the IE 7/Firefox world with .NET and that is the focus of the tools I’m surveying.

For this effort, I define these testing types as:

Functionality Verification – Verifying the customer specified and engineering derived requirements for an application. This also includes acceptance testing for project/contract endpoints or milestones.

Regression Testing – During development and also when releasing new builds – verify that previously implemented functionality works as expected and that there aren’t unexpected side effects from the introduction of new functionality.

Stability Testing – Verification that an application will run without leaking memory, or bogging down both the client and server side and that there aren’t low probability catastrophic events that might bring an application down with no warning and limited visibility into what happened.

Load/Performance Testing – Assess how well an application runs on given hardware so that predictions can be made for the user experience. Establish scenarios of use for the performance testing. (How many times will someone ask – how many users does you app support? – this question doesn’t make sense to me unless you define what a user is doing and the scenarios for that user’s activity).

Selenium Core, Selenium RC, Selenium IDE, Selenium Grid

Note – Before I started this effort I did not realize how invested in Selenium Google is. Looking at the Google videos on YouTube made me realize that Google has hired the initial Selenium developer and is funding internal efforts to expand Selenium. Our use of Selenium can piggyback on this significant effort from Google.

This set of tools seems to be very popular and we’ve looked at using this combination on our app. Selenium in general supports all browsers since the actual operation is a core of Javascript. The IDE portion is enticing – in that it records (from Firefox) a user’s verbs on a web user interface. These actions are saved in "Selenese" – basically an html table that contains the actions done and also can include verification of things found in the resulting HTML coming back from the web server. These test can be placed in a menu of tests to run or can be run from an app using Selenium-RC – a java based testing exec service.

One drawback is that Ajax makes testing an app difficult since there isn’t a standard way to tell when the browser is done rendering your HTML that is shown in the browser. This makes Selenium-IDE difficult to use for recording a test – since you can’t instantly run the test again without a bunch of errors saying that UI elements are not present to be looked at or acted upon (at least for a while). Also – playing games with keystrokes are difficult to record from what the IDE records.  You have to substitute recorded "typing" events in the Selenese so that your app is properly driven – creating Javascript events as normal.

Here are some things I’ve found that are useful:

Selenium: The in-browser acceptance testing tool

Jason Huggins at Google London Test Automation Conference (LTAC) giving a presentation of Selenium’s various components http://www.youtube.com/watch?v=78mts_sKNGs&NR=1 A build/verification environment is demo’d  using various OS’s. A brief overview of Selenium-IDE and its relationship to Selenium-RC – in particular recording a test in Selenese and then automatically converting to one of various languages – Java, Ruby, Python,  C#.

Selenium User Meetup 2008: Lightning Talks, March 4 2008

YouTube Video

Google is funding Selenium development internally to support their Selenium test grid (Mark Striebeck – Google Test Manager).
Selenium Grid is new – supports multiple parallel test machines. End to end web testing is slow because of the comm between clients, web servers, and database. The presentation demo’d 20 Selenium tests running at one time. Any test that works currently for Selenium RC will work in the grid. Selenium Grid is available for download now.

Jennifer Bevan of Google shared experiences of the Selenium Grid work at Google. They have 51K tests per day on their Selenium Farm. Selenium has been adopted as the primary technology for functional testing of web applications within Google. The grid can error out due to Selenium RC bugs that effectively create a DOS on the backend test servers. There has been in house Google work to create utility functions to help out.

Google is feeding back updates to the open source Selenium group.

Selenium 1.0 is coming out – RC, Core, Grid and IDE together.

Selenium 1.1 – IDE enhanced to obey remote control instruction. Coming in a couple of months.

Selenium 2.0 – is going to leverage WebDriver.

GTAC 2007: Simon Stewart – Web Driver

Simon Steward presentation on the Google Channel. http://www.youtube.com/watch?v=tGu1ud7hk5I

Paraphased from the presentation:

"Speed is important"

"Driving a real browser in memory is just going to be slow".
Web Driver is very similar to Selenium RC and uses Java to create testing objects. A big difference from Selenium RC is that Javascript cannot be driven. WD uses direct API’s into the web browser as opposed to Javascript interfaces. This makes WD more efficient than Selenium RC. However, the lack of a Javascript interface makes testing for Ajax completions very difficult. We really need to know when the render is complete and our app has a Javascript flag to check for render complete. WD specifically does not have any mechanism to test for a render complete – you need to delay to handle these issues.  This is really a killer for our app.

FAQ for webdriver: http://code.google.com/p/webdriver/wiki/FrequentlyAskedQuestions

GTAC 2007: Huggins & Stewart – Selenium-RC Vs WebDriver

Huggins & Stewart – Selenium-RC Vs WebDriver at The 2nd Annual Google Test Automation Conference (GTAC) in our New York office on August 23 and 24, 2007 http://www.youtube.com/watch?v=Vlz-WmcrBL8

Using open source tools for performance testing

Goranka Bjedov – Using open source tools for performance testing at Google London Test Automation Conference (LTAC) http://www.youtube.com/watch?v=KQ-wm3rW8_c&feature=related
Interesting point "what is a benchmark test – try to find out what customers’s are doing with the app in the real world, extract some subset of operations  that reasonably reflect the system under real operating conditions and then every time code changes, subject the system to the test under load". Goranka suggest that engineering time be put into creating a benchmark test within the scripting language of the load tool of choice.

This quote puts our problems in perspective "At Google, at any point in time there are a thousand  machines failing that need to come back in a reasonable amount of time". "Our systems are designed so that nobody should be able to see that".
About performance testing – "can our systems support what I think our customers would want".

Google’s requirement for user interface response time on search is that results are returned in less than a second and typically are in the ten’s of milliseconds.
When tests are monitored, a single resource will eventually be the bottleneck as simulated load is increased. Google recommended on Unix platforms, that the best customer experience is received when the limiting resource is not pushed above 80% of a maximum value.  Google speculated that Microsoft’s limits are typically 60%. A problem for test engineers is that marketing groups will want the numbers on throughput when the limiting resource is 100%.

Goggle suggested tools:
JMeter Java Based
Grinder 
OpenSta (Windows based)

General resources for open source testing:
http://opensourcetesting.org
http://testingreflections.org

Further reflections on this presentation from the following blog:
http://robertbaillie.blogspot.com/2006_09_01_robertbaillie_archive.html
Goranka Bjedov also posted an article about performance testing here:
http://googletesting.blogspot.com/2007/10/performance-testing.html