Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Jmeter Wiki" for change 
notification.

The "RobinWilson" page has been changed by RobinWilson:
http://wiki.apache.org/jmeter/RobinWilson?action=diff&rev1=8&rev2=9

  
  === NOTES on "strange pause" during testing run ===
  
- Test conditions:
+ When testing a fairly simple HTTP(S) 'registration' process, enabling the 
"Retrieve All Embedded Resources" flag for the HTTP Samplers caused an 
unexpected 'pause' (~35 seconds in duration) to be regularly added to the test 
cycle. The addition of the "Retrieve All Embedded Resources" flag caused the 
test to increase the amount of data being transmitted from the test servers to 
the JMeter 2.4 client to be multiplied by about 10X. The pauses occurred at 
regular intervals during the test run - where the test would run fine for about 
1 min, and 25 secs, and then 'pause' for about 35 secs, and then continue for 
another 1 min, 25 secs, then pause for another 35 secs, with this pattern 
repeating until the end of the test. One of the key symptoms of the problem was 
that the servers involved and the JMeter client all showed 'idle' (CPU, Network 
I/O, and Disk I/O) during the 'pause' period - indicating that they were not 
'catching up' on handling requests, but that they had nothing to work on during 
the pause. The problem was eventually traced to have 'iptables' enabled on the 
Apache (HTTPS) web server that was being hit directly by JMeter. The iptables 
service is the Linux 'firewall' application. And while it was not filtering any 
of the test packets out, it was parsing each packet - which was substantially 
slowing its ability to service incoming network traffic. Eventually, the server 
would back up on servicing incoming packets to the point that it would fill its 
buffers, and stop accepting requests for a specified 'backoff' period (~35 
seconds). Disabling 'iptables' on the Linux hosts resolved the problem 
completely.
  
+ ==== Test conditions: ====
+ 
-  Client Configuration:
+ ===== Client Configuration: =====
   
   * JMeter 2.4 being run on a Windows XP box
   
@@ -17, +19 @@

   
   * Key Issue - when "Retrieve All Embedded Resources" is enabled, test runs 
for ~500-600 iterations (2400 of the 4 pages + 10X that in embedded resources), 
then pauses for about 35 seconds, then starts running at full speed again. (THE 
PAUSE IS NOT INTENDED, AND IS THE PRECISE PROBLEM EXPERIENCED.)
   
- <br />
-  Server Configuration:
+ ===== Server Configuration: =====
   
   * Apache Web (HTTPS) Server - configured for AJP Proxy to Tomcat Java App 
Server
   

Reply via email to