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    Summon RCA - June 2016

    Confidential Information, Disclaimer and Trade Marks


    This document serves as a Root Cause Analysis for the Summon service interruption experienced by Ex Libris customers beginning on Friday, June 24 and ending on Monday, June 27.

    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

    A disruption in linking to content from Summon was experienced by all Summon Ex Libris customers during the following hours: 

    June 26, 2016 5:06 pm PST to June 27, 2016 1:43 pm PST.

    During the event, any links to content using a proxy were broken and resulted in end users not being able to access their desired content.

    Root Cause Analysis

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

    When addressing an existing encoding bug to fix foreign language links, a regression was introduced for proxied links. While the fix corrected foreign language links, proxied links began returning 404 errors.

    Technical Action Items and Preventive Measures

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

    • We will  extend our testing environment and simulate more customer’s configuration  for better testing of linking rules prior to release
      • We have also identified test customer proxy service credentials for EZProxy, III and HAN proxy credentials for better validation
    • Improved monitoring has been put in place and increased post-release development coverage will be made available.

    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:



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