Introduction

This document serves as a Root Cause Analysis for the 360 service interruption experienced by Ex Libris customers on November 13, 2020.
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 instances in the Seattle Data Center during the following hours: 

November 13, 2020 from  01:04 AM until 03:24 AM PDT time

During the event, the services were intermittent 

Root Cause Analysis

Ex Libris engineers investigated this event to determine the root cause of this issue and concluded the following:

An untuned monitoring of the filesystem caused the volume capacity to reach its limit

The monitor was fine-tuned and additional capacity was added.

Technical Action Items and Preventive Measures

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

The monitoring of the disk capacity has been fine-tuned with a lower threshold