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    Poor response time; iowait above 50%

    • Article Type: General
    • Product: Aleph
    • Product Version: 16.02

    Since our database restore, users are reporting poor response times in all modules, all procedures. These can be in the range of 30 seconds or more to frequent "Server failed to execute after 60 seconds" errors when sending information to or receiving information from the server.

    Circulation reports this occurring on checkin, checkout, patron registration, searching for patron records, displaying patron information etc.

    Cataloging reports this whenever holdings are accessed or when saving records to the server. Acquisitions see this when invoicing, receiving, processing orders etc.

    We have been monitoring the I/O wait with top and it is often in the range of 25 - 40% and hardly ever below 15%.

    This was caused by the lack of the z30_id5 -> z30_id10 Oracle indexes. The fact that the server was spending so much time doing full table scans of the z30 affected the response time for all transactions (-- not just those involving items).

    Additional Information

    Relevant article:   How to tell if Oracle indexes for a particular library are present & VALID  .

    • Article last edited: 10/8/2013