There have been several instances where the OOM killer has killed a mongod process when running one of logical_session_cache_replication* tasks on Enterprise RHEL 6.2. With the num_jobs_available expansion equal to the number of CPUs, we end up running 4 tests concurrently (each using a 3-node replica set) on the rhel62-small distro which is a c4.xlarge (4 CPU, 7.5GiB memory). We should change to use the rhel62-large distro and limit the maximum number of resmoke.py jobs to 12. The rhel62-large distro is a c4.4xlarge (16 CPU, 30GiB memory), so we'll end up running 12 tests concurrently, but have a larger ratio of available memory to number of concurrent tests.