Thank you Peter,
I followed your advice and i downloaded the Tomcat sources, and that is the
results of my investigation:
The class who play the role of status servlet is:
org.apache.catalina.manager.StatusManagerServlet
The information sent to JMeter and displayed in the Monitor results listener
are in the class : org.apache.catalina.manager.StatusTransformer
in the method :
public static void writeVMState(PrintWriter writer, int mode)
throws Exception {
if (mode == 0){
....//This part of the code is not used in the case of the monitor
results
} else if (mode == 1){
writer.write("<jvm>");
writer.write("<memory");
writer.write(" free='" + Runtime.getRuntime().freeMemory() + "'");
writer.write(" total='" + Runtime.getRuntime().totalMemory() + "'");
writer.write(" max='" + JdkCompat.getJdkCompat().getMaxMemory() +
"'/>");
writer.write("</jvm>");
}
You can see here that the data sent by the status servlet are about the memory
used by the JVM and not about the physical memory of the server.
Noureddine
----- Original Message -----
From: Peter Lin
To: Noureddine BEKRAR
Sent: Wednesday, March 01, 2006 1:52 PM
Subject: Re: Performance graph of the Results Monitor Listener
the memory measurements are taken from Tomcat's status servlet, which means
it is the total memory allocated by the JVM. to see, just look at tomcat's
status servlet.
hope that helps
peter
On 3/1/06, Noureddine BEKRAR <[EMAIL PROTECTED]> wrote:
Thank you Peter for your answer.
You said :
...
memory - free memory/total used
...
What i want to know is which memory we speak about here : is it the total
used physical memory on the server or is it the memory used by the JVM or is it
the memory used by Tomcat or the memory used by the requests sent by JMeter....
Noureddine
----- Original Message -----
From: Peter Lin
To: JMeter Users List ; Noureddine BEKRAR
Sent: Tuesday, February 28, 2006 5:33 PM
Subject: Re: Performance graph of the Results Monitor Listener
Since I wrote the sampler and documentation, I'll try to explain it the
best I can.
the performance graph has 4 lines.
health - this line is sort of arbitrary at the moment, but it basically
takes the load and threads to calculate health
load - combination of memory and threads
memory - free memory/total used
threads - busy/total threads
The expected behavior of the graph is the memory usage will show a
regular pattern. The red thread line should remain constant under constant
load. if the red line increases rapidly, it means there's threading issues in
the webapp.
the load should show a regular pattern under constant load, since it is a
combination of memory and thread stats.
hope that helps
peter
On 2/28/06, Noureddine BEKRAR <[EMAIL PROTECTED]> wrote:
Hi,
Can you please tell me which memory is monitored in the "performance
graph" of the "monitor results listener", is it the size of the used memory for
the JVM or is it the memory used by Tomcat.
This is the -not enough clear- explanation about this subject in the
"Building Monitor testplan"
http://jakarta.apache.org/jmeter/usermanual/build-monitor-test-plan.html :
... The performance graph shows for different lines. The free memory
line shows how much free memory is left in the current allocated block. Tomcat
5 returns the maximum memory, but it is not graphed. In a well tuned
environment, the server should never reach the maximum memory...
