Introduction

This document serves as a Root Cause Analysis for the service interruption experienced by Ex Libris customers.
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 EU02 instance during the following hours: 

November 28,  2022, from 13:25  until  13:42 Amsterdam time: During the event, the service was unavailable.

Root Cause Analysis

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

High load on the database server due to multiple internal database memory locks during application transactions which eventually caused some DB process to hang and service interruption.

Once the issue was identified, the hanged processes were killed and the system was recovered to full functionality.

Technical Action Items and Preventive Measures

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

• We are working with the DB vendor to improve DB  configuration
• We have tuned DB internal configuration
• We have tuned and approved application queries and 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.