1. The Need For Speed
A Developer’s Guide to
Distributed Caching with
Velocity AppFabric
Phil Pursglove
@philpursglove
http://philpursglove.blogspot.com
http://www.philippursglove.com/Velocity

2. Agenda
• What is AppFabric?
• Why a Distributed Cache?
• Configuring a client
• Configuring a server
• Managing a cache
• Concurrency
• High availability / load balancing

3. Caching Review
• .NET 1.1
– ASP.NET Cache
• .NET 2.0
– SqlCacheDependency
– Enterprise Library Caching Application
Block
• .NET 4.0
– System.Runtime.Caching assembly
– AppFabric

4. What is AppFabric?
• A combination of two projects:
– A distributed cache
• One logical cache shared across a number of physical
servers
• Already being used by:
– MSDN Forums
– Xbox Live
– MSN
• A session state provider
• In .NET 4.0, a cache provider
– A workflow host
• Beta 2 Refresh released 26th April 2010
– Servers must be .NET 4.0, clients can be .NET 3.5/4.0
• v1 by 30th June 2010

5. Why a Distributed Cache?
• Bigger cache
– Many physical servers contribute to one
logical cache
• High availability
– Multiple servers = fault tolerance
• Increased throughput
– Many servers available to fulfil requests

6. Terminology
• Cluster
– A number of servers running Velocity
– Not related to Windows clustering
• Cache
– A named cache on a cluster
• Region
– A named part of a cache associated to a
single server

7. What Data Can I Cache In
AppFabric?
• Any serializable .NET object
– Reference Data (Shared Read)
• e.g. Product categories
– Activity Data (Exclusive Write)
• e.g. Shopping Basket
– Resource Data (Read and Write)
• e.g. product stock data

8. Configuring the AppFabric
Client
• Two assembly references to add:
– Microsoft.ApplicationServer.Caching.Client.dll
– Microsoft.ApplicationServer.Caching.Core.dll
• Cache hosts can be hard-coded or in
web.config/app.config
• Clients
– Routing vs Simple
– Local caches

9. Using AppFabric 1
• Add/Remove
• Concurrency
– Optimistic
– Pessimistic

10. Using AppFabric 2
• Regions
– Live inside a cache
– Tie a group of cached objects to a specific node

– But adds extra options (Tags) for retrieving the
object 

11. Configuring an AppFabric
Server
• Cluster configuration can be held:
– On a network share (XML Provider)
– In a SQL Server DB (SQL Provider)
• Integrated Security only 
– AppFabric servers must be inside a
domain

12. Managing An AppFabric
Cluster
• Powershell integration
– Can start/stop a whole cluster or
individual servers
– Create new named caches
• But not regions 
– Get cache statistics
• MDCAdmin tool
– WPF app sitting on top of Powershell

13. Summary
• Velocity is going to be great
… in v2 
• v1 is worth looking at as a session
state provider
– The end of sticky load-balancing 

14. AppFabric Launch Event
• Tomorrow afternoon 1630-1730
• Launch event for Windows Server
AppFabric and Windows Azure
AppFabric
• Visit http://www.appinfrastructure.com
for details

15. Questions?
phil@philippursglove.com
http://philpursglove.blogspot.com
http://www.philippursglove.com/Velocity
@philpursglove
http://slideshare.net/philpursglove

16. References
• Documentation on MSDN
– http://tinyurl.com/msdnappfabric
• Velocity team blog
– http://blogs.msdn.com/velocity
– http://blogs.msdn.com/endpoint
• AppFabric blog for IT Pros
– http://blogs.technet.com/appfabric/
• TechEd videos
– http://tinyurl.com/velocityteched
• Mix 09 video
– http://tinyurl.com/velocitymixvideo
• Mix 10 video
– http://tinyurl.com/velocitymix10video
• ARCCast Video
– http://tinyurl.com/velocityscotthavideo
• ScottHa on Velocity
– http://tinyurl.com/velocityhanselminutes
• Deep Fried Bytes on AppFabric
– http://tinyurl.com/deepfriedappfabric

17. References
• AppFabric coverage on StackOverflow
– http://tinyurl.com/stackoverflowvelocity
– http://tinyurl.com/stackoverflowappfabric
• DotNetRocks
– http://tinyurl.com/dotnetrocksappfabric
• Other .NET distributed caches
– NCache - http://tinyurl.com/ncache
– Memcached - http://tinyurl.com/smoe
– Oracle Coherence – http://tinyurl.com/oraclecoherence
– SharedCache – http://codeplex.com/sharedcache
• Extensions Project
– http://tinyurl.com/mscacheext
• Admin Tool
– http://mdcadmintool.codeplex.com/