Primo VE EU00- RCA - October 15_17 2018

Introduction

This document serves as a Root Cause Analysis for the Primo VE service interruption experienced by Ex Libris customers on October 15th & 17th, 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

Intermediate service interruptions were experienced by Ex Libris customers served by the Primo VE instances at our European Data Center during the following time period:

October 15^th, 2018 from 1:33 PM until 3:46 PM Amsterdam time
During the event, the service was intermittent for the environment.

October 17^th, 2018 from 12:50 PM until 1:12 PM Amsterdam time
During the event, the environment encountered performance issues

Root Cause Analysis

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

Extremely long queries in the system caused a huge memory consumption.

After deep analysis Ex Libris engineers found that the length of the query was expended beyond normal length by one of the “query expansion routines”.
As an emergency precaution and in to order to reduce the risk of re-occurrence, the following steps were taken:

1. Temporarily turned off the “did you mean” functionality (which expands the query further) and later re-enabling it
2. Turned off specific expansion routine that deals with citation formatted queries

Technical Action Items and Preventive Measures

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

• Ex Libris engineers restarted the search server nodes to clear the memory which caused the intermittent service
• As an emergency precaution and in to order to reduce the risk of re-occurrence, the following steps were taken:
  • Temporarily turned off the “did you mean” functionality (which expands the query further) and later re-enabling it
  • Turned off specific expansion routine that deals with citation formatted queries
• Ex Libris engineers are working on resolving the defect in the query expansion routines to ensure they do not expand beyond a controlled size.

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