Epsilon is a global marketing and data services leader, and the data powerhouse behind Publicis Groupe following its 2019 acquisition. Specializing in personalized digital media, mass mailing, and high-scale marketing automation for the retail and automotive industries, Epsilon operates at a scale few companies match, functioning as a “global post office” for some of the world’s largest brands.
At the heart of Epsilon’s digital mailing platform, Harmony, is a metadata layer that must support over 100 million email transactions per day without interruption. To modernize this infrastructure and protect it against data inconsistency and downtime at peak volumes, Epsilon turned to Percona. The engagement delivered:
Epsilon
Marketing
8000+
Percona Server for MySQL, Percona XtraDB Cluster, Percona Expert Support
MySQL
Operating at the scale of a global post office comes with infrastructure demands that few database environments are built to handle. Epsilon’s Harmony platform processes metadata for more than 100 million emails every day, tracking every connection, transaction, and delivery event that underpins its clients’ marketing campaigns. For the retail and automotive brands Epsilon serves, a missed or delayed send isn’t just a technical failure; it’s a direct impact on revenue and customer relationships.
Patic Bantas, DBA Manager at Epsilon, oversees the database infrastructure and reliability for Harmony. His team is responsible for ensuring the availability and performance of the metadata layers that drive these global mailing operations. As the platform grew, so did the complexity of the challenge. High-concurrency connections were straining the existing architecture. At the same time,split-brain risk in the cluster meant nodes could lose synchronization and begin serving inconsistent data, posing a serious threat to data integrity at scale.
Managing this kind of environment with legacy architecture was no longer sustainable. Epsilon needed a resilient, highly available database stack capable of handling massive transaction volumes without compromising reliability, and they needed a partner with the deep MySQL expertise to help them get there safely.
Epsilon evaluated partners based on depth of MySQL expertise and the ability to support a complex Cluster and ProxySQL stack. They selected Percona for its proven track record with high-volume MySQL environments and its ability to provide hands-on support through a technically demanding modernization.
Percona worked with Bantas and the Epsilon team to design and implement an architecture built around Percona XtraDB Cluster for high availability and Percona Server for MySQL as the core database engine. ProxySQL was added to manage application routing and query traffic, giving the team more controlled handling of the connection metadata that Harmony generates around the clock.
The solution was designed with Epsilon’s operational reality in mind: any changes to a platform sending 100 million emails per day had to be executed without disrupting active mailing windows or introducing new points of failure.
Percona’s engagement with Epsilon centered on stabilizing and modernizing the database infrastructure underpinning Harmony, with a focus on reducing split-brain failures and connection overload.
By implementing Percona XtraDB Cluster, the team established a synchronous multi-node architecture that keeps all cluster nodes consistent, even under peak load. This directly addressed a persistent split-brain risk by helping keep cluster nodes consistent during high-concurrency mailing windows. ProxySQL was configured to intelligently route application traffic and manage connections, preventing any single node from becoming a bottleneck and giving the team finer control over query management at scale.
Percona Expert Support provided Bantas and his team with ongoing access to senior MySQL engineers, ensuring that as the environment evolved, expert guidance was always available. For a platform operating at Harmony’s scale, the ability to escalate quickly and get authoritative answers, without waiting for a generalist support tier to escalate internally, was a critical part of the engagement.
The result was a modernized, high-availability architecture that kept Epsilon’s “global post office” running reliably, with the resilience to sustain peak volumes without data loss or disruption to client campaigns.
Results
With Percona XtraDB Cluster, ProxySQL, and Percona Expert Support in place, Epsilon achieved a more resilient and scalable database foundation for Harmony. Split-brain risk was reduced, load balancing across high-concurrency workloads was better controlled, and Harmony’s metadata layer sustained more than 100 million daily email transactions while maintaining availability during peak mailing windows.
For the retail and automotive brands that rely on Epsilon to deliver time-sensitive marketing communications, this translates directly into campaign reliability and business continuity at a global scale.
Epsilon is a global leader in outcome-based marketing, helping brands build deeper, data-driven connections with their customers. A subsidiary of Publicis Groupe since 2019, Epsilon specializes in personalized digital media, mass mailing, and high-scale marketing automation, serving major clients across the retail, automotive, and financial services industries.
Resources
