Sierra ; Polaris DC04 - RCA - February 8, 2026

Introduction

This document serves as a Root Cause Analysis for the service interruption experienced by Sierra and Polaris customers–hosted in DC04 (Chicago Data Center).

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 Clarivate is taking to avoid similar cases in future.

Event Timeline

Service interruption was experienced by the single-tenant Sierra and Polaris environments hosted in Clarivate’s Data center in Chicago, during the following days:

February 8, 2026, from 06:49 AM until 04:25 PM CST.

While the total engineering resolution window spanned several hours, the operational impact varied significantly across the customer base.

Most systems experienced a brief service interruption of 30 minutes or less, with many recovering automatically before the disruption was noted.

A subset of environments required a more complex recovery. These systems, upon reboot, necessitated manual intervention by our Support and engineering teams to fully restore all functionalities. Please refer to our technical action items below for the preventative measures being implemented.

Root Cause Analysis

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

A month ago an unexpected fault surfaced on a storage device, triggering a defensive read-only state across all data-center applications. Immediate joint analysis with the vendor identified the underlying defect that caused the read-only condition and yielded a recommended remediation.

The vendor’s suggested solution was applied by the vendor’s engineers, yet the problem recurred afterward, implying that the fix had not been correctly implemented by the vendor.

Our engineers quickly understood the magnitude of the event and acted with sense of urgency to restore all applications and environments to normal operation.

Some systems did not come up cleanly and required triage, remediation and restore activities with more prolonged downtime during February 9th.

Technical Action Items and Preventive Measures

Clarivate has taken the following actions and preventive measures to avoid such an occurrence in future:

· We are working to enhance monitoring across all Polaris environments to enable earlier detection and provide greater visibility of potential issues.

· We are accelerating recovery times for both Polaris and Sierra by improving restart automation and streamlining internal application processes.

· We are working closely with the vendor to conduct a comprehensive technical analysis of the incident, covering every aspect and delivering permanent, long-term solutions.

· We are refining internal procedures and developing an improved startup workflow to shorten recovery timelines and ensure a structured return to service.

· We are upgrading the network and storage architecture for the Sierra and Polaris environments to increase resilience and overall performance.

Customer Communication

Innovative 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