I have upgraded to Gatling 3.0.0 RC4 today and executed one of my scenarios. I have executed this scenario many times in Gatling 2.3.1 without any problem. In Gatling 3.0.0 RC4 I ended up with OOM after approx. 25 minutes.
java.lang.OutOfMemoryError: Java heap space
Dumping heap to java_pid24502.hprof …
Heap dump file created [1302179725 bytes in 11.259 secs]
Load setting - nothing fancy …
setUp(scn.inject(rampUsersPerSec(1) to 5 during (30 minutes)))
.uniformPauses(50) // percent
Take a look at heap dump - looks like none of the sessions are being garbage collected …
The scenario is pretty standard, the only extras I can think of are in configuration: output to Graphite is ON and logging of failed responses is ON. Also, I use 2 feeders (CSV and custom Range).
Happy to provide more details, just tell me what you need.