Introduction

This document serves as a Root Cause Analysis for the Primo service interruption experienced by Ex Libris customers on  August 3, 2025.

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 EU01, EU02, EU03, EU04, EU05, TC EU00 and TC EU04 (ICC) instances at the Amsterdam Data Center during the following time period:

October 6, 2025 from 11:17 AM until October 7, 2025 11:10 AM  Amsterdam time – Performance issues and SSL issues for few customers. 

October 6, 2025 from 11:33 AM until 11:39 AM Amsterdam time – Complete Down time. 

And:

October 9, 2025 from 11:00 AM until 11:10  AM Amsterdam time –Complete Down time.

October 9, 2025 from 12:05 PM until 12:17  PM Amsterdam time –Complete Down time.

During the event, Service was intermittent unavailable for the environments, some experienced slowness and performance issues. 

Root Cause Analysis 

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

High CPU usage on one of our Web Application Firewall devices caused disruptions to the services in the Data Center. Our engineers took some re-routing measures to resolve the issue.  

Once the re-routing took place, some of the customers started to see SSL certificate issues on their environment. The reason for that was that their SSL was installed only on the new WAF and when we bypassed it, some of the certificates were missing on the load balancer. 

With a sense of urgency, the team worked to update and align certificate configuration on both network devices.

Technical Action Items and Preventive Measures 

We have taken the following action and preventive measures to avoid such an occurrence in future:

• Our network team is working with the vendor to understand the sudden increases in usage and to ensure efficient CPU usage and improved performance. 

• Our network team is working on optimizations on the device’s configuration 

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: http://status.exlibrisgroup.com/

These updates are automatically sent as emails to registered customers.