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For a telecomms project, JMeter was used to test a new high-availability integration layer, exposed to a few internal clients. Several instances of JMeter represented the different clients and varying load profiles. The default JMeter XML output is too verbose, and the files grew too enormous, so the "<font color="blue">Simple Data Writer</font>" Simple Data Writer was used to produce much friendlier CSV results files. I wanted to show throughput & response times in blocks of 1 minute; JMeter's inbuilt Graph function was not sufficient to process the volume of data. An example of the type of graph required follows. The reader will see that the JMeter test plan produced variations in load (normal, high & spike), and the response times were quite well-behaved. If the integration layer was performing poorly, the graph would show inconsistent throughput and fluctuating response times. BR attachment:throughput-graph.png BR

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After a test run, all the JTL output files were gathered together (20 or so files) in a bunch of subdirectories. The analysis was conducted on a Windows PC with MinGW/MinSYS and a few other tools (msys-dtk, gnu bc, gnu paste, gVim). For an overview of total vs. projected throughput, I used the shell script {{jtltotals.sh}} (attachment:jtltotals.sh.txt -- kludgy but hey I'm a tester not a developer!). It collates \[total throughput, start time, end time, time elapsed, average response time\] for each output file.  This script will produce a file 'jtl-file-totals.txt'.  A sample of output is shown below.

jtl-file-totals.txt

JMeter-Output-file,total-throughput,start,end,elapsed-sec,elapsed-hms,response-av
WebGUI/output.1/queryFCNs.jtl,33,20061103.105342 local,20061103.105830 local,288,00:04:48,225.59
WebGUI/output.1/queryPackages.jtl,55,20061103.105342 local,20061103.105555 local,133,00:02:13,234.06
WebGUI/output.2/queryFCNs.jtl,42,20061103.113435 local,20061103.114155 local,440,00:07:20,212.12
WebGUI/output.2/queryPackages.jtl,59,20061103.113435 local,20061103.113737 local,182,00:03:02,238.78
WebGUI/output.3/queryPackages.jtl,272,20061103.121135 local,20061103.122042 local,547,00:09:07,260.03
Myserver/output/applyDebit.jtl,22219,20060912.154822 local,20060912.162945 local,2483,00:41:23,1265.12
Myserver/output/queryBalance.jtl,360,20061009.134916 local,20061009.150914 local,4798,01:19:58,96.31
total,23040,,,,,

Conversion of JMeter timestamps

The first field of a JTL output file is a Unix timestamp extended to milliseconds. The above script jtltotals.sh calls another script utime2ymd to convert start & end times into year-month-day.hour-min-sec (yyyymmdd.HHMMss). Usually the JTL timestamps are adjusted for your local timezone (eg. GMT plus or minus a few hours). The utime2ymd script uses the local timezone by default, but can also provide GMT values – useful for converting x-thousand elapsed seconds into hhmmss. (attachment:utime2ymd.txt) Example of usage:

$ utime2ymd  1158477785863 
20060917.192305 local

$ utime2ymd 3601 gmt
19700101.010001 gmt