KYLIN-3321, Set env MALLOC_ARENA_MAX=4 by default.
KYLIN-3321, Set env MALLOC_ARENA_MAX=4 by default.

apache/kylin,apache/kylin,apache/kylin,apache/kylin,apache/incubator-kylin,apache/incubator-kylin,apache/kylin,apache/incubator-kylin,apache/kylin,apache/incubator-kylin,apache/incubator-kylin,apache/kylin,apache/incubator-kylin