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    CN01 - RCA - March 10, 2021


    This document serves as a Root Cause Analysis for the service interruption experienced by Ex Libris customers on Alma CN01

    The goal of this document is to share our findings regarding the event, specify the root cause analysis, outline actions to be taken to solve the downtime event, as well as preventive measures Ex Libris is taking to avoid similar cases in future

    Event Timeline

    Service interruption was experienced by Ex Libris customers served by the Alma CN01 instance at the Chinese Data Center between March 10, 2021 from 05:59 until 09:23 Beijing time. During this time frame customers experienced service degradation (Access through APIs was not affected).


    Root Cause Analysis

    Ex Libris Engineers investigated this event to determine the root cause analysis with the following results:

    A code fix process ran on the system just before the event. This is a very common operation, exactly the same as the one that ran on March 10th on many Alma instances around the world without any negative effect. A close examination showed that this process has a potential flaw where temporary files are deleted unnecessarily. Usually the server will generate these temp files but in this specific case it did not which in turn caused the reported errors.


    Technical Action Items and Preventive Measures

    Ex Libris has taken the following action and preventive measures to avoid such an occurrence in future:

    • Once the problem was reported and identified the servers were restarted and the missing temp files were immediately generated
    • The code fix process was fixed to avoid the unnecessary deletion of temp files

    Customer Communication

    ExLibris is committed to providing customers with prompt and ongoing updates during Cloud events. Ongoing and prompt updates on service interruptions appear in the system status portal at this address:

    These updates are automatically sent as emails to registered customers


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