Introduction

This document serves as a Root Cause Analysis for the Primo 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 Primo MT EU01 instance at the European Data Center during the following hours: 

July 11^th, 2017 from 11:59 PM until 12:20 PM Amsterdam time.

July 24^th, 2017 from 3:44 PM until 4:59 PM Amsterdam 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 database connection pool of the environment’s front end became empty, which resulted in the application’s inability to serve new requests.
This usually happens when a process requires a database connection and then for some reason times out – for example, when waiting for an external resource.

Technical Action Items and Preventive Measures

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

• A monitoring tool that shows why processes are not running as expected was deployed.
• A new database connection pool alert will be implemented. This alert will notify the 24x7 hub before the connection pool is empty.
• In parallel, our Primo R&D engineers are continuing to investigate the root cause of the issue in order to potentially be able to create a fix that will prevent this issue from happening again.

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