Hi stack, In the HFile.java, I found following comments by you.
"The current implementation does not offer true multi-threading for reading. The implementation uses FSDataInputStream seek()+read(), which is shown to be much faster than positioned-read call in single thread mode. However, it also means that if multiple threads attempt to access the same HFile (using multiple scanners) simultaneously, the actual I/O is carried out sequentially even if they access different DFS blocks (Reexamine! pread seems to be 10% faster than seek+read in my testing -- stack). " I want multiple threads or processes to access a same HFile file simultaneously, each thread or process create a new HFile.Reader and Scanner. I think it is no-problem. Do you think it ok?
