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    Primo MT EU02 RCA October 1 and 5 - 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 1 and 5, 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 Multi tenant EU02 instance at the Europe Data Center during the following hours: 

    October 1 from 02:35 PM until 4:03 PM Central Europe time zone (CET).
    October 5 from 12:10 PM until 12:55 PM Central Europe time zone (CET).
    October 5 from 04:46 PM until 5:37 PM Central Europe time zone (CET).


    During this interruption, Primo was extremely slow and became not available for customers on the European multitenant EU02 environment.

    Root Cause Analysis

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

    An unexpected load on Search engines and on the Front Ends had taken place. The extensive load on the system elements had caused the slowness and in the extreme cases it had caused the system to build a high queue that prevented it from operating at all.

    Technical Action Items and Preventive Measures

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

    • To accommodate the load, the environment had been updated with the following –
      o Additional computing unit (CPU) were added to the Search Engines
      o Additional Front End was added to the environment
    • Monitoring had been set to have a more sensitive thresholds to allow identification of possible slowness earlier.

    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: