JMeter Running Out Of Memory At 400MB on WAMP

Question

I am running form submission tests on a website (WAMP) to create new users. Currently, my thread breaks when moving from 6-7 users to 8. The current configuration which breaks is:

1 Thread
8 Users
20 Loops

Each form submission contains approx. 25 input fields with no more than 25 characters in each.

I have removed all but one View Results In Tree module, increased the heap size to 4096 (which I come nowhere near), and am running it in non-GUI mode which made improvements but I am still running out of memory well before I should think. System monitor shows that Java is only using around 400MB.

Error says:
java.net.SocketException: No buffer space available (maximum connections reached?): connect

This results in an equal number of failed MySQL INSERTS (e.g. # Buffer Errors (in Results Tree) == # Failed Inserts).

I have looked into some of the Jmeter tuning tips, but none of them seem to apply beyond running in non-Gui. Is this Jmeter or is my application not handling the submissions correctly? Is this too many input fields per submission for this load? With only 5 users, everything works fine. Thanks in advance.

Answer 1

There is a known issue in Windows with leaky sockets. For those that fit the description, and if you are already running Jmeter in x64 mode but are still experiencing premature memory lapses during stress tests, this may help solve the problem: https://support.microsoft.com/kb/2577795