1. A method for enhancing performance for data processing in a distributed file system, the method comprising: instantiating an input/output (I/O) manager on a machine among a plurality of machines that implement the distributed file system; and utilizing the I/O manager to perform cache management optimization including: (a) determining that the machine employs a heuristic for triggering readaheads for sequential read requests; overriding the heuristic so as to deterministically trigger the readaheads for all sequential read requests; (b) determining that the machine is configured to automatically cache data into a buffer on the machine after the data is accessed; detecting that a specific size of data has been accessed; instructing the machine to invalidate the cached data in the buffer; and (c) determining that the machine is configured to include a time delay before committing data from the buffer to a disk on the machine; overriding the time delay so that the machine commits the data from the buffer to the disk without the time delay.