This stress test contain two bash files which are "query.bash" and "stress.bash".
The scripts depend on mockd process(https://github.com/pivotal/mock-data) to generate some fake data.
After mockd compilation and please fill the path into "stress.bash" MOCKD_PATH variable.

"query.bash" is an infinity loop to query data from external table in the test database.
Running this script after "stress.bash" start. It sleeps 2-7 seconds then send SIGTERM 
signal to gpfdist. If gpfdist exit successfully, it will restart gpfdist again and do this previous
task again until gpfdist hang.

gpfdist does not hang through three hours test.
