The Role of FIDO in a Cyber Secure Netherlands: FIDO Paris Seminar.pptx
Distributed Caching with Velocity AppFabric
1. The Need For Speed
A Developer’s Guide to
Distributed Caching with
Velocity AppFabric
Phil Pursglove
phil@philippursglove.com
http://philpursglove.blogspot.com
http://www.philippursglove.com/Velocity
http://twitter.com/philpursglove
http://slideshare.net/philpursglove
2. Agenda
• What is AppFabric?
• Why a Distributed Cache?
• Configuring a client
• Configuring a server
• Managing a cache
• Concurrency
• High availability / load balancing
4. Cache-Aside
• The cache-aside pattern
– See if the item you want is in the cache
– If it isn’t (a cache miss),
• Go and get it i.e. from the DB
• Put it in the cache
– If it is,
• Cast it to the desired type and return it
5. 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 released 1st March 2010
– Servers must be .NET 4.0, clients can be .NET 3.5/4.0
6. 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
7. 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
8. 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
9. 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
10. Using AppFabric
• Add/Remove
• Concurrency
– Optimistic
– Pessimistic
• 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
15. References
• Documentation on MSDN
– http://tinyurl.com/msdnappfabric
• Velocity team blog
– http://blogs.msdn.com/velocity
• 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
