Major Description
DFS_CLIENT_MMAP_CACHE_THREAD_RUNS_PER_TIMEOUT is set to the wrong value. It should be set to dfs.client.mmap.cache.thread.runs.per.timeout, but instead it is set to dfs.client.mmap.cache.timeout.ms. The result is that mmap segments cached in the ClientMmapManager will take much longer to timeout than they should.