The Need For Speed

A Developer’s Guide toDistributed Caching with

Velocity Windows Server AppFabric

Phil Pursglove@philpursglovehttp://philpursglove.blogspot.com

Agenda• What is AppFabric?

• Why a Distributed Cache?

• Configuring a client

• Configuring a server

• Managing a cache

• Concurrency

• High availability / load balancing

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

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

• An ASP.NET session state provider

• In .NET 4.0, a cache provider– A workflow host

• V1 released to web 4th June– Servers must be .NET 4.0, clients can be .NET 3.5/4.0

Why a Distributed Cache?

• Bigger cache

– Many physical servers contribute to one logical cache

• Increased throughput

– Many servers available to fulfil requests

• High availability

– Multiple servers = fault tolerance

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

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

Using AppFabric

• Add/Remove

• Concurrency– Optimistic

• Version-based– Pessimistic

• Lock-based

• Tags

• Regions– Live inside a cache– Use for a set of logically related cached items e.g. Products– Tie a group of cached objects to a specific node

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

Managing An AppFabricCluster

• 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

Summary

• AppFabric brings the cloud inside your organisation!

• Distributed caching is a powerful way to bring scalability to your applications

– Throughput

– High availability

Questions?

@philpursglove

http://philpursglove.blogspot.com

http://www.philippursglove.com/Velocity

References• V1 Download

– http://tinyurl.com/appfabricdownload • 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

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/