campusM EU01 RCA August 30, 2017

Introduction

This document serves as a Root Cause Analysis for the campusM EU01 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 campusM EU01 instance at the Europe Data Center during the following times: 

August 30, 2017 from 5:55 PM until 6:05 PM Amsterdam 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 identified that an unindexed foreign key constraint caused a heavy consumption on the database, resulting in deadlocks and a switch to a database recovery mode.

Technical Action Items and Preventive Measures

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

• 2 additional indexes were created to optimize future database queries
• Similar database keys were reviewed and corrected accordingly
• Ex Libris engineers have allocated additional memory resources to increase resilience.

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.

Publication History