Skip to main content

Serendipity

Recently, I was testing a new feature for a client, it had a known bug, that I'd found in prior testing, for which we'd figured-out a work-around. I was now performing further testing of the feature, hoping to discover more issues and figure out how it behaves a little better.

Does not apply to testers.
By this time, the work-around had become the norm - the expected mode of operation for the feature. Essentially this 'bug' had been found and was now fixed. Time had moved on. So what did I do? I ignored the work-around, applied my 'test load' to the system and activated the new feature. The failure was somewhat spectacular. A short while later the entire system was inoperable and a restart of several servers was required.

This was interesting. If I'd had expectations of what would happen, then it would of been for something simpler, less severe and closer to what had happened when I first found the bug that required the workaround.

After some investigation, I had found the likely cause. The system had a mis-configuration causing load to be incorrectly balanced (everything was being sent to [only] one of two servers). Speaking to the programmers, it became clear that the issue was caused by the code used in the work-around. Not only that, the work-around helped to mask the issue - because it protected the servers from the load!

In short, If I had used the work-around (that is: expected usage) I might never have seen the failure. I've seen this effect before and I suspect many testers have. By moving outside the 'safe operating parameters' you discover 'stuff'. You discover not only what can go wrong in the extremes, but what might happen in normal, run-of-the-mill usage. I'm deliberately saying 'stuff' here because we don't know what it's going to be. I am building new knowledge through experience.

Before I went on my 'voyage of discovery', I had certain preconceptions. I also had, it turns out, great gaps in my knowledge. By breaking the rules - or realising they don't apply and only hinder investigation - I put my self in a better position to learn more.

On a related note, some mainstream companies (OK... Apple) might benefit from some similar testing - outside the specifications. It might help them avoid negative publicity.

Comments

Popular posts from this blog

Betting in Testing

“I’ve completed my testing of this feature, and I think it's ready to ship” “Are you willing to bet on that?” No, Don't worry, I’m not going to list various ways you could test the feature better or things you might have forgotten. Instead, I recommend you to ask yourself that question next time you believe you are finished.  Why? It might cause you to analyse your belief more critically. We arrive at a decision usually by means of a mixture of emotion, convention and reason. Considering the question of whether the feature and the app are good enough as a bet is likely to make you use a more evidence-based approach. Testing is gambling with your time to find information about the app. Why do I think I am done here? Would I bet money/reputation on it? I have a checklist stuck to one of my screens, that I read and contemplate when I get to this point. When you have considered the options, you may decide to check some more things or ship the app

XSS and Open Redirect on Telegraph.co.uk Authentication pages

I recently found a couple of security issues with the Telegraph.co.uk website. The site contained an Open redirect as well as an XSS vulnerability. These issues were in the authentication section of the website, https://auth.telegraph.co.uk/ . The flaws could provide an easy means to phish customer details and passwords from unsuspecting users. I informed the telegraph's technical management, as part of a responsible disclosure process. The telegraph management forwarded the issue report and thanked me the same day. (12th May 2014) The fix went live between the 11th and 14th of July, 2 months after the issue was reported. The details: The code served via auth.telegraph.co.uk appeared to have 2 vulnerabilities, an open redirect and a reflected Cross Site Scripting (XSS) vulnerability. Both types of vulnerabilty are in the OWASP Top 10 and can be used to manipulate and phish users of a website. As well has potentially hijack a user's session. Compromised URLs, that exp

Test Engineers, counsel for... all of the above!

Sometimes people discuss test engineers and QA as if they were a sort of police force, patrolling the streets of code looking for offences and offenders. While I can see the parallels, the investigation, checking the veracity of claims and a belief that we are making things safer. The simile soon falls down. But testers are not on the other side of the problem, we work alongside core developers, we often write code and follow all the same procedures (pull requests, planning, requirements analysis etc) they do. We also have the same goals, the delivery of working software that fulfills the team’s/company's goals and avoids harm. "A few good men" a great courtroom drama, all about finding the truth. Software quality, whatever that means for you and your company is helped by Test Engineers. Test Engineers approach the problem from another vantage point. We are the lawyers (& their investigators) in the court-room, sifting the evidence, questioning the facts and viewing t