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    Alma NA instances - RCA - October 5, 2016

    Confidential Information, Disclaimer and Trade Marks


    This document serves as a Root Cause Analysis for the Alma service interruption experienced by Ex Libris customers on October 5, 2016


    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 Alma NA01, Alma NA02 and Alma NA03 instances at the North America Data Center during the following hours: 


    October 5, 2016 from 10:16AM until 10:23AM Chicago Time Zone


    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:


    We have identified an infrastructure defect on one of the core switches (hardware element). As a result of the defect, the switch was rebooted. Following that reboot, a failover to the adjacent redundant Core Switch took place, but a miss-configuration on the load balancer had prevented that failover of the load balancer to take place – this has caused the system disruption.

    Technical Action Items and Preventive Measures

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


    • To prevent future occurrences, the load balancer’s High Availability misconfiguration has been fixed to allow for proper failover
    • An in-depth analysis is being done for the load Balancer's High Availability configuration to investigate further optimizations
    • Core Switches upgrade option to a firmware version that does not hold the identified defect is being analyzed and an upgrade will be scheduled based on findings

    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: