Module 1–Windows AppFabric Cache

1. Module 1–Windows AppFabric Cache Introduction and Architecture

2. Outline • Why caching? • Introduction to Windows Server AppFabric Cache • Overview of Cache features

3. Typical Web Architecture

4. Why use caching? • Most applications end up needing • Robustness • Speed • Scalability • This is especially true in the web world • Need to scale can sneak up quickly • Almost any web application can benefit from caching • Services can benefit as well

5. Core caching concepts • Caching • Storing a copy of data closer to application logic, away from its source • Distributed Caching • A set of nodes in a farm that coordinate to create a unified view of a cache to a caching client • Expiration • When an object is removed from the cache because of staleness • Eviction • When an object is removed from the cache due to low memory conditions

6. What is the AppFabric Cache? • A Distributed cache for “data” • In-memory cache • Uses an explicit API • The “Data” can be • CLR Object • XML • Binary data • Optimized for the cache-aside pattern in this version • Programming against the cache is explicit • Changing the cache doesn’t update the original data store

7. What is Windows Server AppFabric? • A set of technologies and capabilities integrated into Windows Server and IIIS • Designed to make building, managing, and scaling IIS applications easier • Ships as part of Windows Server AppFabric 2010 Wave 1 • Part of Windows Server • HA requires Windows Server 2008 Enterprise or DataCenter Editions. • Requires .NET 4.0 WORKFLOW HOSTING MONITORING CACHING ACCESSCONTROL SERVICEHOSTING

8. AppFabric architecture • Cache runs on N nodes • Nodes that share configuration are part of a single Cache Cluster • Runs as a Windows Service (one service per server node) • Typically not the same servers as the client (web) tier • More memory is better • In-memory copy cache is optional setting (“Local Cache”) • All the cache nodes in a cluster are part of a fabric • Share configuration • Communicate • Cooperate • Same algorithms that support Windows Azure’s fabric

9. Stripped memory across server nodes CacheServer#1 obj#4 obj#2 obj#3 CacheServer#2 Cache Cluster obj#1 CacheServer#3 Objects in memory

10. AppFabric Cache

11. AppFabric Cache advantages • Native .NET API • Scalability • Performance • Typically linear as more nodes are added • LocalCache increases raw performance • High Availability • Distributed nature safe guards against cache client and server failures

12. Installation and configuration • Installs as part of Windows Server AppFabric • Not dependent on other AppFabric features (e.g. service and workflow management) • First node creates cluster configuration • Other nodes are configured to just join existing cluster • Nodes can be added to or removed from the cluster at any time – cluster automatically reconfigures itself

13. Cache Cluster configuration • Configuration abstracted behind a provider model • OOB providers • SQL Server Database • Network share(XML file) • Configuration Provider model open

14. Cache size configuration • You must configure “projected” size • 1-5 nodes (small) • 6-15 nodes (medium) • > 15 nodes (large) • Cache optimizes itself based on this setting • Setting not affected by actual number of nodes added to cluster • You can change this (and other) configuration settings on a stopped cluster

15. Administration • PowerShell cmdlets are used to administer the cache cluster Remember – PowerShell can also be called from .NET Code!

16. Cache creation • Caches are named constructs • Multiple items can live in one named cache • Key for each item must be unique • Partition design based on • High availability requirements • Grouping based on logic • New-Cache cmdlet • Each named Cache can have its own settings for • Availability • Expiration • Eviction

17. Cache Clients • Rich API • Centers around the DataCache type • Can be .NET 4.0 or .NET 3.5 SP1 • WCF NetTcpBinding used under client API • Can be configured in code or config • Simple configuration – server name and port • Can configure N servers • Configuring max N is recommended • Client is “smart” • Requests routes to cache node where data lives automatically • Routing table updated on a constant basis by cache cluster • Client essentially becomes part of the cluster fabric • Local cache configured at client • Local cache automatically updated (no guaranteed speed)

18. Programming the cache //create DataCacheFactory based on config file var dcf = newDataCacheFactory(); //get the cache named "TestCache" var cache = dcf.GetCache("TestCache"); //Add an item called "Test" - throws if exists cache.Add("Test", newData { TheData = "Test" }); //Put an item called "Test2" - overwrites if exists cache.Add("Test2", newData {TheData = "Test2" }); //Get "Test3" - add if not in cache (cache-aside) var test3 = cache.Get("Test3") asData; if (test3 == null) { test3 = newData {TheData = "Test3" }; cache.Add("Test3", test3); }

19. Client API • Clients can specific named Regions for items • Regions are stored on one cache host only • Created implicitly if not specified • Cache Items can be tagged • Tagging enables items to be retrieved without specific knowledge of the item • Client can register for notification of cache events • Bulk API available as well

20. Security • Domain Based Security Option • On by default • Domain Account / Local Account based Authentication • Only authorized servers can join the cluster • Only authorized clients can connect to the cluster • Transport Level Security • Turn on/off Signing or Encryption • Can turn off Cache Security • Security always has a performance implication • Use Firewalls, IPSec, VLANs to protect cache grant-cacheallowedclientaccount  MyDomain\Machine1$ grant-cacheallowedclientaccount  MyDomain\Jon

21. Management • PowerShell enables configuration and some monitoring • Logging • Cache participates in ETW tracing • Logging available on both client and server • Rich set of performance monitor counters for monitoring both cache and host performance

22. ASP.NET Session Provider • Custom Session Provider included with Cache • Just a configuration change • enables session state to be cached across a cluster • You may want to enable HA on the cache used <sessionStatemode="Custom"customProvider="SessionStoreProvider"> <providers> <addname="SessionStoreProvider"type="Microsoft.ApplicationServer.Caching.DataCacheSessionStoreProvider, Microsoft.ApplicationServer.Caching.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"cacheName="BlueYonderSession"/> </providers> </sessionState>

23. Caching Patterns • It is extremely useful to classify the type of data you are going to cache as either: • Resource, Activity, or Reference Data • Classification will inform what features to use • Use the correct feature for the correct type of data • Will help you to design the property number of caches • i.e. No need for HA for Reference data • More on this later

24. Summary • Windows Server AppFabric Cache is a distributed application cache • Caching is important to application scalability • Explicit caching API available to .NET 3.5 SP1 and .NET 4.0 • ASP.NET Session provider an implicit way to take advantage of the Cache’s capabilities

25. Questions?