NCache

Definition

NCache is a distributed in-memory cache built specifically for .NET applications, providing a shared caching layer that lets multiple application instances read and write session state, database query results, and other frequently accessed data without repeatedly hitting a backend database. It is designed to plug directly into the .NET ecosystem, including ASP.NET session state providers, Entity Framework second-level caching, and SignalR backplane support.

Overview

NCache targets a familiar scaling problem in .NET web applications: once an application runs across multiple servers behind a load balancer, session state and frequently read data can no longer live safely in a single server's process memory, because a user's next request might land on a different server. NCache solves this by distributing cache data across a cluster of cache servers that any application node can query, removing the need for sticky sessions and reducing repeated round trips to the primary database. Mechanically, NCache clusters cache servers together and partitions or replicates cached data across them, similar in principle to other distributed caching systems, while exposing a client API and configuration model tailored to .NET idioms rather than a generic key-value protocol. It integrates as a session-state provider for ASP.NET and ASP.NET Core, meaning session data is transparently stored in the distributed cache instead of in-process or in a database, and it offers a second-level cache provider for Entity Framework and NHibernate so that repeated ORM queries against unchanged data can be served from the cache rather than re-querying the database. It also supports pub/sub messaging and can serve as a SignalR backplane, letting real-time notifications fan out correctly across multiple web server instances. Compared with general-purpose distributed caches like Redis or Memcached, NCache's differentiator is its native .NET integration depth: rather than requiring developers to wire up a generic client library and build their own session or ORM caching glue code, NCache ships pre-built providers that plug into standard .NET extension points. Where Redis or Memcached are language-agnostic and widely used across many platforms, NCache's design center is specifically the Microsoft development stack, giving it tighter default integration at the cost of being less universally applicable outside .NET. In practice, enterprise .NET applications adopt NCache to remove session-affinity requirements from load balancers, to cut database load by caching frequently read but rarely changed data such as product catalogs or configuration, and to enable real-time features across a web farm using its SignalR backplane support. It is typically installed and managed via its own cache server processes, with client libraries added directly to .NET application projects. The trade-offs include being a commercial product (with a more limited open-source edition) in a space where Redis is free, open-source, and has broader cross-platform and cross-language adoption, plus a smaller ecosystem of third-party tools and community knowledge outside the .NET world. Teams standardized on .NET who want deep first-party integration may prefer NCache; teams working across multiple languages or platforms typically find Redis a more universally supported choice.

Key Features

• Provides distributed session state storage for ASP.NET applications
• Offers second-level caching for Entity Framework and NHibernate
• Supports SignalR backplane integration for real-time messaging
• Distributes and replicates cached data across a cache server cluster
• Ships pre-built providers tailored to .NET framework idioms
• Supports pub/sub messaging patterns for distributed .NET apps
• Removes the need for load-balancer session affinity
• Available in both commercial and limited open-source editions

Use Cases

Alternatives

Frequently Asked Questions

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