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    Primo MT NA02 RCA October 21 2015

    Confidential Information, Disclaimer and Trade Marks


    This document serves as a Root Cause Analysis for the Primo service interruption experienced by Ex Libris customers on October 21.2015.


    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 Primo MT NA02 instance at the North America Data Center during the following hours: 

    October 21, 2015 from 01:55 pm until 02:15 pm U.S. Central Time.


    During the event, the service was unavailable for the environment.

    Root Cause Analysis

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

    An unexpected load from known and un-known sources caused the system to receive extensive amount of calls, higher than expected.

    Technical Action Items and Preventive Measures

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

    • A code correction was added to the environment to allow better performance of the front ends.
    • Monitoring changes were made to allow identifying the source of each unexpected load.
    • Procedure changes were done to allow quick blocking of a source creating an unexpected load.
    • Application changes are planned for the next software release to allow mitigating the load and prevent impact to the environment.

    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: