Major Description
There is a bug in IntegrationTestBigLinkedList that it reads the wrong config key to calculate the wrap size for the linked list. It uses num mappers, instead of num recors per mapper. This has not been caught before, because it causes the test to fail only if 1M is not divisible by num mappers. So launching the job with num mappers 1, 2, 4, 5 would succeed, while 6 will fail, etc.