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    Summon - RCA - June 5, 2019


    This document serves as a Root Cause Analysis for the Summon service interruption experienced by Ex Libris customers on June 5, 2019

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

    June 5th, 2019 from 1:03 PM until 1:23 PM Pacific Time.


    During the event, the Summon service was online, but displayed zero results for search requests. The issue was identified almost immediately, and Summon Systems Engineers worked quickly to shift customer traffic over to our Secondary Datacenter.


    Root Cause Analysis

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

    The root cause is related to an issue in the  Rights Distribution Service, which permitted incomplete Rights to be applied to an active Datacenter instance.

    The issue was resolved immediately once Production Traffic was shifted over to the Secondary Data Center.

    Technical Action Items and Preventive Measures

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

    • As an immediate action, Ex Libris Engineers rebuilt and tested the Rights Distribution Service Cache on the affected Datacenter instance then brought the Datacenter back online after complete Rights were applied to the affected Search Cluster.

    • In order to prevent such issue in the future, new checks are being added to the Rights Distribution Service and to the Daily Rights Service, to ensure that incomplete Rights are not promoted.

    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:

    • Optimized the content on Summon in order to reduce the impact of high search rate on performance. This helped reduce the duration of the performance degradation but has not resolved it entirely.
    • Additional hardware has been added to Summon in order to further optimize performance and help prevent future performance degradation.

    Publication History

    Date Publication History
    June 13, 2018 Initial Publication



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