iTest ships with heap size set to 384M in iTest.ini file. That is just a guess for what user will need. User can go ahead and add a single step of "readFile" on a 1 Gig file and iTest will get out of memory error. This does not mean that iTest has a memory problem - it implies that the user has to be aware of the memory requirements of the testcases he/she is writing. Generally, in most cases, people should not and do not worry about because 384M is good enough for most people. But when you start getting out of memory errors, it is time to check memory requirements of testcases. Generally increased memory usage comes from a few factors:
1. user is trying to parse huge amounts of data (a large table being response mapped or a large textual response is being stored and processed). I have seen people process responses as big as 50 Mbyte with iTest set to just 384M of heap and getting frustrated with out of memory exceptions.
2. user is create a large number of threads which process significant amounts of data but not as large as #1. But total amount happens to be in excess of hundreds of mega bytes.
3. Sometimes, out of memory happens over time. iTest will cache certain amounts of data to improve performance. But over days, if one starts reaching the limit of heap size due to caching, one can get out of memory exceptions. Only solution in this case is to increase the heap size.
My first recommendation to people is:
1. memory is too cheap, human analysis time is too expensive - add memory to the system and set iTest heap size to 1 Gig or 2 Gigs and do not spend time analyzing how much memory I need.
2. If #1 is not an option, then turn on iTest's preference to show heap status and single step through your testcase and see which step's execution causes a spike in memory usage. See if you can reduce the size of response to be analyzed by iTest (using response filters) or not mapping the huge response.
