Introduction

This document serves as a Root Cause Analysis for the Ulrich service interruption experienced by Ex Libris customers on March 27, 2023.
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 Ulrich environment in the Seattle Data Center during the following hours: 

March 23, 2022 from  11:21 until 15:24 Seattle time

During the event, the services were unavailable.

Root Cause Analysis

Ex Libris engineers investigated this event to determine the root cause of this issue and concluded the following:

During a non-disruptive planned activity, a newly added security monitor and scanner that protects the system caused a traffic load which ended in a service disruption.

Once the issue was identified, the newly added components were stopped and the service recovered.

Technical Action Items and Preventive Measures

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

• The newly added security monitor and scanner was stopped.

• Our engineers are working with the vendor on a fix