Case Study: RavenDB Cluster Hosted on Azure eliminates severe database freezes with RavenDB and Windows Server 2025

RavenDB Cluster Hosted on Azure ends 20-second freezes with RavenDB

A customer running a RavenDB NoSQL database cluster hosted on Azure was experiencing severe, sporadic service freezes that lasted over twenty seconds. These pauses, which occurred on powerful Windows Server 2019 machines, were causing cluster elections and dropped client connections. The challenge was traced to massive .NET Garbage Collection pauses triggered by a Windows kernel-level lock contention during memory management operations.

RavenDB collaborated with the customer and Microsoft Support to diagnose the issue as a scalability limitation in the Windows Server 2019 Memory Manager. The solution implemented was an upgrade to Windows Server 2025, which featured a re-architected Memory Manager. This upgrade, recommended by RavenDB and Microsoft, completely resolved the issue, eliminating the freezes and returning the cluster to full stability.