vioperf skip read

i would like to know the exact meaning of vioperf. how is it calculated and what value can be considered good


  • LenoyJLenoyJ - Select Field - Employee

    Focus on 'counter value/core' for READ and WRITE.
    As per this:

    Vertica requires a minimum read/write speed of 40 MB/s per physical core of the CPU. However, for best performance, you should have 60–80 MB/s per physical core.

  • pvannuffpvannuff Vertica Customer

    thanks lenoy, but my questions was not correct. Sorry for that. My title was OK but my question was not.
    I would like to know the exact meaning of vioperf "SKIP READ". how is skip read calculated and what values can be considered good.

  • LenoyJLenoyJ - Select Field - Employee

    SKIP READ tests reading non-contiguous data blocks. The docs do make a mention that -

    When evaluating performance for minimum and recommended I/O, include the Write and Read values in your evaluation. ReWrite and SkipRead values are not relevant to determining minimum and recommended I/O.

  • Note vioperf itself says "The minimum required I/O is 20 MB/s read and write per physical processor core on each node, in full duplex i.e. reading and writing at this rate simultaneously, concurrently on all nodes of the cluster. The recommended I/O is 40 MB/s per physical core on each node. " therefore that minimum contradicts the article at which says the minimum is 40 MB/s per physical core. Also note that defining what a physical core is in VMware or in the cloud is problematic/impossible.

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