Here is a a example that I have constructed in a simple MySQL DB (rather than use their data). For this purpose a table called log containing start and end time.

.

Here is the code I wrote. Any optimisation to the SQL welcome. (I am but a performance tester interested in the data)


SELECT tL.StartTime, (select count(1) from test.Log where StartTime = tL.StartTime) FROM test.Log tL where StartTime > 0 group by StartTime order by 1

Here is the output from running the query. It should be noted that it presents the concurrency at the start time of a new transaction.

For the JavaScript I am interested in I added the function below at the top of the script.

function now()
{
var d = new Date();
return (d.getTime());
}

At the beginning of the function I want to time I added

var time = now();

At the end of the function I added

alert(“Time to execute = ” + (now()-time)+”);

void my_start_transaction (char *name)
{
lr_vuser_status_message("Starting Transaction %s",name);
lr_start_transaction(name);
return ;
};
vuser_init()
{

return 0;
}

LoadRunner Function Override

Ticket Crash

Moral of the story. Remember to get this set up before you are the only person in the office on a Sunday.

If DB time is significantly higher than the elapsed time then things are waiting.

Elapsed: 60.10 (mins)
DB Time: 197.70 (mins)

The example in the book shows DB time 20x the elapsed.

Step 2: Instance Efficiency

Hopefully these will be above 90%

Buffer Nowait %: 100.00
Redo NoWait %: 100.00
Buffer Hit %: 99.88
In-memory Sort %: 99.95
Library Hit %: 98.84
Soft Parse %: 97.81
Execute to Parse %: 83.30
Latch Hit %: 100.00
Non-Parse CPU: 99.89
Parse CPU to Parse Elapsd %: 0.00 %

The last one shows how much time the CPU is parsing SQL statments, so the lower the better.

Step 3: Top 5 Timed Events

This tell you where the highest resources are being consumed. In the book the example is the db file sequential read would indicate that there where full table scans being performed.

For my AWR report is looks like most of the resources are used in the remote connections over DBlink. Now I need to find out if this is due to a poor network or just user load.

http://www.oracle.com/technetwork/topics/index-089595.html

http://www.infoq.com/presentations/LMAX

However, when I connected my laptop to the test environment response times where much worse. It wasn’t the test environment as fiddler showed that back end performance was fine. My laptop was a higher spec than the client PC so I started up perfmon and observed high CPU as the main cause. However, it was not the Internet explorer process that was consuming the CPU but the McAfee intrusion protection process. Little known to me this was a recent corporate wide download (ok, I probably got the email about it but hey, I get a lot of emails!)

So. the delay was primarily the anti-virus script scanning the JavaScript. Disabled on the clients PC but not on
my laptop Luckily, there is a registry setting that will disable scanning for a particular URL. With that in place I could get around to debugging the JavaScript with IE 8.

Moral of the story check to see if script scanning is enabled on yours abs the clients PC.