The $HVR CONFIG directory – is this just for log files? How much disk space is needed?

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  • #10995
    ggoodrich
    Keymaster

    Disk space in the $HVR_CONFIG directory is used for several purposes

    On the hub-machine:

    1. Storage of hvr logfiles (growing, but managed by hvrmaint)
    2. Temporary storage of transaction files.
      1. The capture job reads all the changes, compresses them and sends them to the hub-machine
      2. These files are immediately picked up by the integrate job and deleted when the changes are applied to the target database.

    So normally there is 0 or 1 files (per channel). However when the integrate job is stopped (crashed or suspended), these files are starting to pile up. The growth of disk-space can be estimated: as the amount of Ingres journal / Oracle archive files that are generated (in a day) times the HVR compression ratio (typically 90 % or higher, but use 80 % to be safe). After a couple of days you will decide to use HVR Load / Refresh to reinitialize the channel, instead of using the transaction files to process all the changes. So storage for a couple of days would suffice.

    On the capture / integrate machine:

    During replication:
    Spilling of big transactions that can not be held in memory, e.g. used with long data types (CLOB etc) or a single transaction that updates 1 million rows.
    Estimated: size of the/your biggest transaction * HVR compression ratio
    During row-wise refresh / compare: for sorting tables.
    Estimated: 3 * (size of largest table) * (parallelism in compare or refresh)
    Since HVR 4.6.2, temp files for cases 1, 3, 4 & 5 are compressed unless $HVR_TMP_COMPRESS_LEVEL=0 is set. Before HVR 4.6.2 files for case 2 (sorting during row-wise) are only compressed if HVR_SORT_COMPRESS=1 is set. Since 4.6.2 files for case 2 are compressed unless $HVR_SORT_COMPRESS_LEVEL=0 is set. So for versions more recent than HVR 4.6.2 the estimate should
    Estimated: 3 * (size of largest table) * (parallelism in compare or refresh) * (HVR compression ratio)

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