Recently a client had an urgent request to monitor a HTTPS URL due to poor availability and performance. No problem, give me the URL and I’ll have the monitor set up and running in 10 minutes. However, a simple task turned into an investigation of Vugen certificates and Windows security …
A recent client engagement presented me with an interesting challenge when scripting for a performance test of Cognos (version 10.1). Cognos uses asynchronous communication between the client and Cognos server; which is essentially polling by the client to the server, to determine the progress of a report being generated. Rather …
One of the problems that occurs on occasion when using VuGen, are problems with Internet Explorer when starting a recording of a Web HTTP/HTML protocol script. These problems can manifest in different ways; for example, a hanging or unresponsive IE window; a windows error message; or a VuGen crash.
Lately we’ve had an annoying problem of an Active Directory (AD) account that is used for our HP Business Process Monitor (BPM) scripts getting locked at random times. Because it’s an intermittent problem, it’s hard to track down where the request is coming form. I wasn’t getting alerted straight away …
LoadRunner has a whole bunch of logging options. These can be specified in your script’s runtime settings, or specified in your script’s code with lr_set_debug_message(). There are some gotchas when changing your logging options with a C function call, so I have written some functions that will be helpful.
IMPORTANT UPDATE:HP Loadrunner 11 is now available. This new version now natively supports Windows 7 and Windows Server 2008. I recommend upgrading to this version for full Windows 7 integration, and Internet Explorer 8 support. The below article refers to earlier Loadrunner releases. Windows 7 has finally been released, and …
Video has seen a massive surgance on the internet with the launch of YouTube and other video sharing web sites. This raises some interesting challenges beyond simple scripting in VuGen; with a combination of Javascript, Adobe Flash and HTTP partial download support. This article will show you how to play …
LoadRunner/VuGen supports both Web (HTTP/HTML) virtual users and Media Player (MMS) vusers, but it does not allow you to create a multiple protocol script using these two protocols. Fortunately, with a little bit of hacking, you can create a multi-protocol vuser with these two protocols yourself.
Sometimes an application running on a client (even a web broswer) will send the IP address of the client machine to the server at the Application layer, rather than the Network layer. This is surprisingly common with web-based apps designed to run on a company’s intranet. To make a BPM …
I recently created some BPM scripts for the BMC Remedy Action Request System 7.1 web client. This Tech Tip contains some of the things that I learnt. My favourite part of this exercise was proving that the person from BMC who said “we have already tried, and found that it …
Imagine that you have created a BPM script that monitors one of your critical business systems from 10 locations around the world. The application only allows users to log on once, so you must find a way to have each location use a different login account for the application. Unfortunately …
VuGen is a great tool for developing scripts to emulate business processes for performance testing or application monitoring, but there are small number of changes that would make it an even better tool. Read on for my list of VuGen feature requests…
Many years ago I had a team member who would always answer “yes” when I asked if he had finished the LoadRunner script he was working on. Invariably he had not finished the script. So I sat down and wrote a checklist for him, and told him that he should …
If you studied programming, you probably know a few little factoids like “global variables are bad”, and “goto is considered harmful”. Some people can even explain why (and in what situations) these statements are true.
Client-side certificates are a way to more securely identify a user of a web application. VuGen supports client-side certificates, but there are one or two gotchas…
This is a repository of code snippets. Please send me any useful sections of code that you have written. Note that this repository does not contain trivial examples (i.e. something you could learn by looking at the example code in the LoadRunner Online Function Reference – accessed by pressing F1 …
Let’s imagine that you want to execute arbitary SELECT, INSERT, UPDATE and DELETE queries against a MySQL database from a VuGen script. Obviously it is easiest to use the JDBC libraries from a Java-based script, but most people aren’t licensed for any of the Java-based vuser types. It is much …
In DNS-based load balancing, a website visitor will request a URL (like www.jds.net.au/tech-tips/). Their web browser will do a DNS lookup of the hostname (www.jds.net.au), and the DNS server will return the IP address of one of several web servers; possibly in a round-robin fashion to distribute the load across …
LoadRunner 9.5 was released today and, as mentioned by the LoadRunner Product Manager, the focus has been on refining current functionality rather than adding completely new features. This is not meant to be an exhaustive list (or a replication of the readme file), but it covers the features that I …
Let’s say that you have to determine the difference between two dates (represented as strings) and express the result in seconds (which could be positive or negative). How would you do this in VuGen?
Occasionally you will find that you must write some code in VuGen to continuously check that the system has completed something, before you continue. Two examples that I have found recently were:
Someone asked me once if there was a way of putting think time into a VuGen script that could not be ignored by changing the runtime settings. There are very few situations I can think of where this would be a good idea, but it is certainly possible to force …
Recently I ran a test at a company which had a performance test environment with multiple web servers, but no load balancer. To spread my virtual users evenly across the web servers, I made a simple modification to my script.
VuGen isn’t just a tool for load testing and application monitoring, it can be used to automate any repetitive task on a web application. In this example, a JDS web security expert had found that a page on a content-managed website allowed anyone to request any file in the database …
A common question from people creating web-based VuGen scripts is how to handle timestamp values that are sent as part of a name/value pair in an HTTP request.
Occasionally you will find that you need to create a VuGen script for a web application which changes the number of name-value pairs which are sent with a POST request. This tech tip shows you how to handle this situation by dynamically constructing a POST body.
Anyone who works with VuGen should know that they should compare strings using the standard C function strcmp(), rather than the equality operator (==). In the example below, there are three string variables that each contain “hello world”. Comparing the strings using strcmp() shows that all the strings are the …
One of the main drawbacks with VuGen is the inability to easily store data for later retrieval, and the lack of interscript communication. I had this exact problem on a recent assignment, the problem was that the business process involved a batch process that needed to run before the rest …
LoadRunner does not come with a monitor for Tomcat. Fortunately, you can easily create one in about 5 minutes…
One of the quick ways to identify those areas in a VuGen script that requires correlation is to record it twice and manually compare the two scripts. Built in to VuGen is the tool WDiff, a basic file comparison tool. However, I have found that it is rather limiting in …
It is possible to test web services using the standard Web (HTTP/HTML) virtual user type instead of the Web Services vuser type. The main disadvantage of this is that you cannot generate your SOAP body from the WSDL file using the VuGen wizard. But if you know what your XML …
Recently JDS was given a good reminder of why VuGen’s Download Filters are an important product feature. Someone created a BPM script to monitor the performance and availability of the JDS website. Suddenly our website traffic looked like this on Google Analytics…
If you are trying to create a LoadRunner script for a SAP Web Dynpro application, and you are having problems correlating the SAPEVENTQUEUE in your POST request, then this Tech Tip is for you…
On very rare occasions you may encounter a web-based application that causes VuGen to throw an error during code generation. Every time this has happened to me, it has been solvable without having to talk to HP Software Support. Read on for my tips…