Error messages and possible causes
This page lists some common error messages that may be seen in the JMeter log file or in sampler responses (e.g. when using the View Results Tree listener)
The most likely cause is trailing spaces in the script. May be easiest to see this by looking in the JMX file.
Exception java.lang.OutOfMemoryError: requested nnnn bytes for promotion. Out of swap space?
Not enough memory was available to Java to run the test. There are numerous possible causes, the most likely is using Listeners that use a lot of memory, such as Aggregate Report and View Results Tree. You can increase the amount of memory by editting the jmeter.bat file or the jmeter shell script. Use non-GUI mode if possile. See Reducing resource requirements
java.net.SocketException: Unconnected sockets not implemented
This occurs when using SSL (https) with JMeter 2.3.2 (or earlier) and Java 1.6. This has been fixed in versions after 2.3.2. Alternatively, switch to Java 1.5.
The problem was caused by a change in the way Sockets are created in Java 1.6. JMeter (and a quite a few other applications) did not override all the SocketFactory methods, so when Java 1.6 started using a different method, the application code stopped working.
java.net.SocketException - followed by - Unexpected end of file from server
This means that the server has terminated the connection, possibly because of an application bug in the server, or more likely there was something in the request that it did not like. The server may respond with an error message in the response body; check the response to see if this gives any clues. If not, and the "same" request works in a browser, then you will need to compare what JMeter is sending with what a browser sends, see DifferentBehaviour.