Introduction

This document serves as a Root Cause Analysis for the Primo service interruption experienced by Ex Libris customers on June 24, 2018.

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 APAC01 instance at the APAC Data Center during the following hours: 

June 24th, 2018 from 17:10 PM until 18:22 PM Singapore time.

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:

The reactive database rules initiated a new execution plan to use a full table scan which affected the search functionality in a way that made the system unavailable

To solve this the DB was restarted to restore the previous plan.
  

Technical Action Items and Preventive Measures

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

• Restart DB and application to have the system back to full functionality
• Created SQL profile to force selection of good DB plan.

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/