Uploaded image for project: 'HPCC'
  1. HPCC
  2. HPCC-29160

Compressed writer can write too much, if flush() called when nothing to write

    XMLWordPrintable

Details

    • Bug
    • Status: Resolved
    • Not specified
    • Resolution: Fixed
    • None
    • 9.0.0
    • None
    • None

    Description

      Examining the stats for serial4a.ecl (regression test program), showed a spillwrite activity recording a "SizeDiskWrite" as 308 (across 4 nodes=284+8+8+8).  The related spillread showed that 1048832 bytes were read. .

      The spilled were compressed files which had a 1MB cache/block size.  This explains the large spill read size. 

      I believe the 308 bytes is the actual size written of the data for the spill file and 1048832 may be the physical size written to disk, cause from the use of compressed file type & 1MB block size.

      However, this it is still confusing to observe that a large read was made from what appears to be a small file.

      jakesmith ghalliday 

       

      Attachments

        1. screenshot-1.png
          screenshot-1.png
          7 kB
        2. spillwrite.bmp
          spillwrite.bmp
          323 kB
        3. spillread.bmp
          spillread.bmp
          337 kB

        Issue Links

          Activity

            People

              jakesmith Jake Smith
              shamser Shamser Ahmed
              Votes:
              0 Vote for this issue
              Watchers:
              3 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: