http://www.scaleoutsoftware.com/products/stateServer/index.html


ScaleOut StateServer
ScaleOut™ Software introduces a breakthrough storage solution for workload-data that cost-effectively delivers the reliability and performance your company needs. ScaleOut StateServer runs as a distributed, software service on every Web or application server in a server farm to store and provide session-data across the farm. Using its StoreSafe™ patent pending technology, the software automatically replicates workload data between servers so that critical data are never lost if a server fails. Access to session state is fast, and performance and storage capacity increase as your Web farm grows. ScaleOut StateServer provides uninterruptible and fast access to storage that a standalone database server (or even a failover database cluster) cannot duplicate, and its performance grows without bottlenecks to meet the demands of the world's largest server farms. It provides the ideal session-data storage solution for e-commerce and other mission-critical services.

ScaleOut StateServer installs as a standard Windows software service and uses your Web farm's existing LAN. Once installed, it operates in a fully transparent manner to Microsoft ASP.NET applications, saving and retrieving session-data objects for Internet clients. Under normal operations, ScaleOut StateServer automatically balances the amount of storage used by each server in the farm, adjusting the relative usage by each server to the amount you require. When a computer fails or loses network connectivity, ScaleOut's patent pending StoreSafe™ technology automatically retrieves its session objects from replicas stored on other servers in the farm and creates new replicas to maintain redundant storage. To ensure uninterrupted access, up to three copies of each stored object are maintained on different servers. When an offline computer later rejoins the farm, it transparently regains its share of the storage workload. As new servers running ScaleOut StateServer are added to the Web farm, they automatically expand storage capacity and increase performance.





ScaleOut StateServer is the only software product that automatically scales storage capacity and performance as your Web farm grows by adding new servers. It is significantly less expensive (for three-server farms, at least 3X lower cost and 10X lower cost/update) than failover database clusters, and it offers sub-ten second recovery that cannot be duplicated by failover clusters.


Breakthrough Technology and Performance
Forget the "split brain" problems of failover clusters. ScaleOut StateServer employs StoreSafe patent-pending technology which guarantees that replicated objects always have the latest updates. ScaleOut StateServer's proprietary, lightweight protocol stack dramatically speeds up network operations, and its patent-pending heartbeat protocol quickly detects server failures without flooding your network with multicast heartbeat packets. Dynamic load balancing keeps the storage load evenly distributed as servers join or leave the farm, and intelligent replication ensures uninterrupted access to data while making efficient use of the farm's resources. ScaleOut StateServer is designed to scale its capacity and performance without bottlenecks across a farm of up to 64 servers.

Simplified Management and High Security
ScaleOut StateServer's self-managing features keep your management costs low. Servers automatically join together to form or expand a "farm-wide" store. Since all stored objects are accessible from any server, your load balancer can direct Web requests to any server in the farm. ScaleOut StateServer automatically balances its workload to maintain high performance, and it automatically recovers and "self-heals" after a server fails.
You can manage ScaleOut StateServer from any server in the farm using its easy to use, console or a command line control program. These management tools give you complete control over ScaleOut StateServer's operations, notify you of failures and configuration changes, and ensure close coordination with your Web load balancer.

ScaleOut StateServer is designed from the ground up to maximize security. Multiple security mechanisms are employed to keep unauthorized servers from participating in storage operations, and all network messages are protected from attack. All management operations are password protected.

The Best Session-State Storage Option for ASP.NET
Microsoft's ASP.NET gives you several storage options for session objects:



With its fast response time, scalable design, highly reliable storage, and cost-effectiveness, ScaleOut StateServer offers the best solution for storing ASP.NET session objects. No changes are required to your ASP.NET programs. ScaleOut StateServer transparently saves and restores session objects on each Web access. Performance tests (PDF 110KB) have shown that ScaleOut StateServer can improve response time by more than 6X over the use of a backend database server to store session objects.