Agile Performance Testing - Testing Experience

(2) After completing the selection of feature model variabilities,
the engineer requests the derivation of this new instance.
The GenArch derivation tool will check the entire architecture
model, individually processing its elements and verifying
in the configuration model if the element is dependent
on one or more features. It will therefore create new instances
only for the required elements, in accordance with what
was requested in the feature model of the new instance.
(3) Finally, the tool produces an Eclipse framework project as a
result of the derivation
process.
This contains only
those implementation
elements
that match the
product first designed
in the initial
feature model
configuration and
specified by the
application engineer.
2.2.2 Generated script
final customization
Due to our project’s
characteristics and
constraints, which we
will describe in the last
section of this article,
we decided to organize
the project using the
GenArch derivation
tool, in order to ensure
that the generated
Eclipse project could
contain the test script
specified according to
the variabilities and its
values set in step (I).
However, we still need
to go through the sixth
and last step of our approach,
where the generated test scripts will receive final customizations
and adjustments in order to enable correct execution
using the performance test tool JMeter. In this section, we
will describe the necessary steps to ensure a perfect coupling and
execution of the generated test scripts.
(I) Initially, the .jmx (JMeter test scripts standard extension) file
available inside the Eclipse project, which is generated by
GenArch during new instance derivation, must be loaded
into JMeter.
(II) Next, JMeter is used to capture all information provided by
the browser, with the intent of capturing transactions (operations)
that could not be represented in GenArch models,
but which are still part of the test script.
(III) The captured JMeter data must be inserted into the correct
execution position within the generated test script. All extra
information needed, like customized variables, need to be
manually configured in the added transactions, in order to
ensure that the items previously configured using GenArch
can be correctly accessed;
(IV) Next, test script needs to be run for the first time, in order
to ensure that it works as designed. If it doesn’t, we need to
make the necessary adjustments and corrections;
(V) At last, we have the final test script, which consists of all the
information generated by GenArch and JMeter’s recorded
transactions data which have been added. This will finally be
available for test execution as planned by the test team.
3. Deriving a performance test script example
Figure 4 below shows a feature model created for deriving performance
test scripts as described in the previous sections. The picture
shows how the GenArch derivation tool shows the selection
of a new test instance, in which we can define the features we
want to include for the new test script together with its respective
values.
Figure 4 – Configuration of a new test instance
For example, the value of the Number of Users element has been
set to 100 (one hundred) and can easily be modified by double
clicking on it. We can also see that the selections of elements like
Search and View Results in Graph and several features have automatically
been eliminated due to restrictions previously defined.
The selection determines the template customization with JMeter
elements (code), which are related to the features selected.
In our example the selection shown has produced the test script
displayed in the picture below, which was produced with the intent
of validating the response time of a search operation for a
web search application.
As we pointed out before,
we had to perform
some adjustments as a
final step in order to include
all desired features
in the test script and to
ensure its proper execution.
To make the generated
test script complete
and ready for execution,
missing transactions
and operations were
added producing the ini- Figure 5 – Derived Test Script
56 The Magazine for Professional Testers www.testingexperience.com