Tag: Advice

Using LoadRunner to send an email

I recently read a question on a LoadRunner user forum (http://osdir.com/ml/LR-LoadRunner/2010-08/msg00072.html) asking whether it was possible to get Loadrunner to send an email.

I started thinking how useful this could be, for example, my DBA always wants to know when a test finishes so he can restore the database on the test system. He often asks me to ring him when a test finishes. This is fine, but can be a nuisance when running a long test, for example over a weekend or evening.
Wouldn’t it be good if we could use LoadRunner to send an email when the scenario finishes?

I played around with an old DOS command line email program (BLAT).
BLAT can be downloaded here.
http://sourceforge.net/projects/blat/files/

Install BLAT into c:\blat and create a file containing your message body called Test.txt.

This command can then be used to send an email.

c:\blat\blat.exe c:\blatTest.txt -subject "Test Complete" -to [email protected] -server mailserver.domain.com -f [email protected] -iu username -ipw password

The sample script in my GitHub repository will email the contents of a file with the subject line “Test Complete”. It is also possible to send email attachments using the -attach switch.

https://github.com/richardbishop/LoadRunnerSamples/tree/master/SendMail

 

Deleting bad lines of data from multiple parameter files.

When performance testing it is common to find some lines of test data which are no longer valid. They may be user IDs which have expired or simply no longer exist in your test database. Finding and removing these bad lines of test data from parameter files can be time-consuming.

This batch file, prmclean.cmd can be used to remove known bad data from all data files in a data folder.  The batch file does not prompt for folder names and currently relies on the .dat files residing in a folder called LR_TestData.

The batch file can be easily modified to work with any text files.  No additional software is required (e.g. PERL) and this batch file will run on any windows PC.

Batch file Description of action
IF EXIST LR_TestData_old  rd LR_TestData_old /s /q

md LR_TestData_old

 

 

REM Copy all data files to “LR_TestData_old”

for %%d in (h) do (

for /f “delims=” %%a in (‘dir LR_TestData*.dat /b’) do (

copy LR_TestData%%a LR_TestData_old

)

)

 

REM Loop through the .dat files writing contents without bad data into new .tmp files

for %%d in (h) do (

for /f “delims=” %%a in (‘dir LR_TestData*.dat /b’) do (

findstr /V /G:bad.txt LR_TestData%%a > LR_TestData%%a.tmp

)

)

 

 

 

REM Delete old .dat files

del LR_TestData*.dat

 

REM Rename .tmp files into .dat files

ren LR_TestData*.tmp *.

 These lines create a folder to keep a copy of the original data files.

 

 

This loop copies all the current data files into a folder called LR_TestData_old.

 

This loop copies data into new data files (with .tmp suffix) without the lines of “known bad” data contained in the file “bad.txt”

 

 

 

Finally the old data files are deleted and the new temporary (.tmp) files are renamed (.dat)


Usage:
Copy the file prmclean.cmd into the folder containing the LR_TestData folder.  Create a text file in this folder called bad.txt containing the “known bad” data.  Run the prmclean.cmd command.

prmclean.cmd screenshot

Sample code:
A sample of this code which can be used to further develop this function is available here.

UNIX performance monitoring with LoadRunner

On my current project, I need to monitor UNIX system performance. I’m currently waiting for a new version of application code to test, so I thought that I’d look into some of the UNIX performance counters that I’m going to monitor.

I’m very familiar with Windows performance monitoring but less so with UNIX, so I thought that I’d try to compare UNIX performance counters with Windows performance counters. When monitoring the performance of a UNIX system using LoadRunner you need to enable RSTATD on the server being tested.

Once you’ve enabled RSTATD it’s a simple matter to tell your LoadRunner controller to monitor the UNIX ststistics for the server under test. All you need is it’s IP address. Once you add the server to the list of monitored servers iN LoadRunner Controller you se a number of counters which LoadRunner can monitor.

 

download

 

Many of these counters are broadly equivalent to Windows performance counters. The table below describes the equivalent Windows counter and describes it’s purpose. I’ve tried to define the UNIX counters and where applicable I’ve described the Windows and UNIX counters.

 

UNIX counter Windows Counter Description
Average Load* N/A The sum of the number of processes waiting in the run queue plus the number currently executing.
Collision rate N/A The total number of network collisions/sec
Context switch rate System – Context Switches/sec The rate at which processors switch from executing one thread to another. High switch rates can indicate performance problems as servers juggle multiple running applications.
CPU utilisation %Processor Time The percentage of elapsed time that the process spends executing non-idle threads.
Disk traffic %Disk time The percentage of elapsed time that the disk(s) are  busy servicing read or write requests.
Incoming packets error rate Packets received errors The number of packets received containing errors that precvent them from being delivered to a higher OSI layer protocol.
Incoming packets rate Packets received/sec The number of packets received on the network interface
Interrupt rate Interrupts/sec Average rate at which the processor receives and services hardware interrupts. Processes generate an interrupt when they finish a task and need to report that fact to the CPU.
Outgoing packets error rate Packets outbound errors The number of packets that can’t be transmitted due to errors
Outgoing packets rate Packets sent / sec The rate at which packets are sent on the network interface
Page-in rate Pages Input/sec The rate at which pages are read from disk to resolve hard page faults. Hard page faults occur when a process refers to a page in virtual memory which is not in it’s working set or available elsewhere in physical memory and has to be read from disk.
Page-out rate Pages Output/sec The rate at which memory pages are written to disk to free up space in physical memory.
Paging rate Paging rate The rate at which pages are read from disk or written to disk.  This is the sum of Pages Input/sec and Pages Output/sec.
Swap-in rate N/A The number of pages read into memory per second
Swap-out rate N/A The number of pages written out of memory per second
System mode CPU utilization Processor – %Priviledged time The percentage of elapsed time that the processor spends executing user threads (i.e. running applications)
User mode CPU utilization Processor – %User time The percentage or elapsed time that the processor spends executing priviledged or system mode threads.

 

*Average Load is not clearly defined and it is important to understand that it represents a moving average over time rather than a snapshot of actual performance. Because Load Average is the sum of two performance statistics (queue length and the number of processes currently executing) it is hard to use it to compare the performance of dissimilar systems. An Average Load which would be acceptable on one system might be unacceeptable on another. The best description that I’ve found for Average Load was “Linux Load Average – Not Your Average Average”, written by Neil Gunther of Performance Dynamics and it can be found at this URL. http://luv.asn.au/overheads/NJG_LUV_2002/luvSlides.html

Thanks to Tim Nichols of CheckPoint Technologies for his questions which encouraged me to clarify the description of Average Load.