Thursday, December 19, 2013

3 easy step to test your website with Selenium from Java.

In this post I want to cover how quickly test website with Selenium.
In my scenario I had issue on some prod server where after some time we get OOM (OutOfMemory), server is .net IIS, after few quick manual test we was not able to reproduce issue on any our test env. So then Selenium comes to play.

Step one: download.

Selenium IDE is written on top of Firefox - it is Firefox plugin. Download it from:
You need 2 pieces to play: IDE and server. When you install IDE, you'll be ask to restart browser, then you'd see in the tools menu "Selenium IDE".

Step two: record & replay.

You're ready to play - just create your test case, click on "Record" and open the page that you want to play with.
Finish of that is script containing steps that you was doing on page. Replay them to make sure that everything is working. If you'll have error that server is not ready: go to command line and start selenium server: java -jar selenium-server-standalone-{version}.jar 
My advice is to do this step couple of time to get familiar how Selenium is working / how is recording steps-clicks, and how actually replay is going through your website - also it looks cool ;-).
When you finish - save it. You also can export it - in my case I export it to jUnit4 format.

Step three: jUnit.

Run from your development IDE (eclipse/netbeans/intelliJ/..).
Create new project in eclipse, then copy body of generated jUnit from previous step. To run test in eclipse you need libraries, you can download them from same page: Just add them to your project dependency... and you ready to rock.

You can also use this example maven project:


How to make concurrent calls? use Executors from my post:

       public void start(){
                ExecutorService executor = Executors.newFixedThreadPool(CONCURRENT_USERS);
                  List<Future<Long>> list = new ArrayList<Future<Long>>();
                  for (int i = 0; i < NUMBER_OF_USER_SESSIONS*CONCURRENT_USERS; i++) {
                    Callable<Long> worker = new FirefoxWorker(i);
                    Future<Long> submit = executor.submit(worker);
                  // now retrieve the result
                  for (Future<Long> future : list) {
                    try {
                    } catch (InterruptedException e) {
                    } catch (ExecutionException e) {

CONCURRENT_USERS - is what is the number of users accessing webpages at single time.
NUMBER_OF_USER_SESSIONS - is how many interactions do you want to have.
Overall number of "visits" is multiplicity of both above.

In my solution I created user_id adding to standard user "i" - next number of execution. You may think about different solution - Hopefully I can present you how to incorporate Disruptor with defined handlers, ... soon ;-)

Friday, December 6, 2013

Java: Code review tools

Rietveld - code review tool running on Google App Engine, for use with Subversion .

Gerrit2 - Java solution for use with GIT.


Rietveld - code review tool running on Google App Engine, for use with Subversion .

Rietveld is in common use by many open source projects, facilitating their peer reviews much as Mondrian does for Google employees. Unlike Mondrian and the Google Perforce triggers, Rietveld is strictly advisory and does not enforce peer-review prior to submission.

Git is a distributed version control system, wherein each repository is assumed to be owned/maintained by a single user. There are no inherit security controls built into Git, so the ability to read from or write to a repository is controlled entirely by the host's filesystem access controls. When multiple maintainers collaborate on a single shared repository a high degree of trust is required, as any collaborator with write access can alter the repository.

Gitosis provides tools to secure centralized Git repositories, permitting multiple maintainers to manage the same project at once, by restricting the access to only over a secure network protocol, much like Perforce secures a repository by only permitting access over its network port.

Gerrit Code Review started as a simple set of patches to Rietveld, and was originally built to service AOSP. This quickly turned into a fork as we added access control features that Guido van Rossum did not want to see complicating the Rietveld code base. As the functionality and code were starting to become drastically different, a different name was needed.

Gerrit2 is a complete rewrite of the Gerrit fork, completely changing the implementation from Python on Google App Engine, to Java on a J2EE servlet container and a SQL database.

Web 3 - blockchain layers

Layers from a blockchain perspective. My plan is to write 5 articles:  1 Intro: Web 1.. 2.. 3.. 2 Layers in crypto.  [this one] 3 Applicatio...