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    Summon - RCA - February 12, 2020


    This document serves as a Root Cause Analysis for the Summon service interruption experienced by Ex Libris customers on February 12th, 2020

    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 Summon instance at the North America Data Center during the following hours: 

    February 12th, 2020 from 10:37 AM until 10:47 AM CST Time.

    During the event the service was unavailable

    Root Cause Analysis

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

    • The CDI Search API, now used by Summon, experienced an unexpected memory growth in a cache system due to growth in rights by combined Primo and Summon users.  This increase in memory led to the Search API becoming unresponsive and a system down event.

    Technical Action Items and Preventive Measures

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

    • On the day of the event, systems were bounced which alleviated the issue.  A rolling bounce of the systems was put in place as a short term measure to address memory issues as there is interplay between this issue and the issue experienced on February 11.

    • On February 14, memory was added to all the virtual machines that host the API applications.  Heap allocated to the applications was also increased, ensuring they would have adequate resources to utilize the new cache structures.


    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:

    Publication History

    Date Publication History
    February 19, 2020 Initial Publication
    February 25, 2020 Update



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