Implement Data Driven Caching with Visual Studio 2003 and 2005

1
Implement Data Driven Caching with Visual Studio
2003 and 2005

• Stephen Forte
• CTO Corzen Inc
• Microsoft Regional Director NY Region (USA)

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Agenda

• ASP.NET Data Controls
• About the ASP .NET Cache Engine
• Output Caching
• SQLCacheDependency

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Binding in a Stateless Environment

• Binding in ASP.NET is really a metaphor
• Controls are not so much actively bound as they
  are associated with a data source
• Binding manager is really a server-side HTML
  generation engine
• Must use caching or session state to persist data
  changes
• Code required to implement bound control events
  like Edit, Delete, Update
• Adding rows takes special effort

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ASP.NET DataGrid

• Lightweight list-bound server control that will
  display data in a table of columns and rows
• Provides style and appearance properties
• Provides sorting and paging
• Provides selection and editing
• Fully programmable
• Datagrid drastically reduces the code you have to
  write vs. ASP Classic

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Populating the DataGrid
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Simplified Data Binding

• Data binding expressions are now simpler and
  support hierarchical (XML) data binding

lt!-- ASP.NET 1.x data binding expression --gt lt
DataBinder.Eval (Container.DataItem, "Price")
gt lt!-- Equivalent ASP.NET 2.0 data binding
expression --gt lt Eval ("Price") gt lt!-- XML
data binding --gt lt XPath ("Price") gt
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DataSource Controls

• Declarative (no-code) data binding

Name
Description
SqlDataSource
Connects data-binding controls to SQL databases
AccessDataSource
Connects data-binding controls to Access databases
XmlDataSource
Connects data-binding controls to XML data
ObjectDataSource
Connects data-binding controls to data components
SiteMapDataSource
Connects site navigation controls to site map data
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SqlDataSource

• Declarative data binding to SQL databases
• Any database served by a managed provider
• Two-way data binding
• SelectCommand defines query semantics
• InsertCommand, UpdateCommand, and DeleteCommand
  define update semantics
• Optional caching of query results
• Parameterized operation

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Using SqlDataSource
ltaspSqlDataSource ID"Titles" RunAt"server"
ConnectionString"serverlocalhostdatabasepubsi
ntegrated securitytrue" SelectCommand"select
title_id, title, price from titles"
/gt ltaspDataGrid DataSourceID"Titles"
RunAt"server" /gt
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Populating the GridView
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Agenda

• ASP.NET Data Controls
• About the ASP .NET Cache Engine
• Output Caching
• SQLCacheDependency

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What is the ASP .NET Cache Engine?

• Ability to save versions of pages in cache and
  not have to work to rerender the page
• The ASP.NET cache is private to each application
  and stores objects in memory
• The lifetime of the cache is equivalent to the
  lifetime of the application
• When the application is restarted, the cache is
  recreated
• Single most inexpensive way to dramatically
  increase performance of your ASP .NET Application

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Designing for Caching

• Leverage the built-in ASP.NET built-in caching
  features
• Output Caching
• Fragment Caching
• Cache API
• Recommendation
• Specifically design your pages around these
  features can lead to massive perf wins

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Agenda

• ASP.NET Data Controls
• About the ASP .NET Cache Engine
• Output Caching
• SQLCacheDependency

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Output Caching

• Caches the static result of an ASP.NET page
• Declarative lt_at_ OutputCache gt directive
• Optional Output Cache APIs can also be called
  programmatically
• Duration- The amount of time in seconds in which
  a page may be output cached.
• This time period is calculated by taking the time
  of the request, if the page is not already in the
  cache, and adding the number of seconds.
• The duration value also sets the HTTP expires
  header.

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Output Caching Options

• Caching Options
• Duration
• Time item exists in the cache
• Remember Scavenging
• VaryByParam
• Varies cache entries by Get/Post params
• Name param, separate by semi-colons, supports
• VaryByHeader
• Varies cache entries by Http header
• VaryByCustom
• Override method within Global.asax to custom vary
  by whatever you want (you control the cache key)

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Caching Options

• VaryByParam
• VaryByHeader
• VaryByCustom
• File Dependency
• Fragmented Caching

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Agenda

• ASP.NET Data Controls
• About the ASP .NET Cache Engine
• Output Caching
• SQLCacheDependency

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SqlDataSource and Caching

• SqlDataSource supports declarative caching of
  results through these properties

Name
Description
EnableCaching
Specifies whether caching is enabled (default
false)
CacheDuration
Length of time in seconds results should be cached
CacheExpirationPolicy
Specifies whether cache duration is sliding or
absolute
CacheKeyDependency
Creates dependency on specified cache key
SqlCacheDependency
Creates dependency on specified database entity
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Caching Query Results
ltaspSqlDataSource ID"Countries" RunAt"server"
ConnectionString"serverlocalhostdatabasenorth
wind..." SelectCommand"select distinct
country from customers order by country"
EnableCaching"true" CacheDuration"60"
/gt ltaspDropDownList ID"MyDropDownList"
DataSourceID"Countries" DataTextField"country"
AutoPostBack"true" RunAt"server" /gt
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SQL Cache Dependencies

• New cache dependency type
• Embodied in SqlCacheDependency class
• Configured through ltsqlCacheDependencygt
  configuration section
• Links cached items to database entities
• ASP.NET application cache
• ASP.NET output cache
• Compatible with SQL Server 7, 2000, 2005

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Preparing a Database

• Use Aspnet_regsql.exe or SqlCache-DependencyAdmin
  to prepare database

aspnet_regsql -S localhost -E -d Northwind -ed
Server name
Trusted connection
Database name
Enable database
Not necessary for SQL Server 2005
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Preparing a Table

• Use Aspnet_regsql.exe or SqlCache-DependencyAdmin
  to prepare table

aspnet_regsql -S localhost -E -d Northwind -t
Products -et
Server name
Trusted connection
Database name
Table name
Enable table
Not necessary for SQL Server 2005
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Preparing Web.config
ltconfigurationgt ltconnectionStringsgt ltadd
name"Northwind" connectionString"serverlo
calhostdatabasenorthwind..." /gt
lt/connectionStringsgt ltsystem.webgt
ltcachinggt ltsqlCacheDependency
enabled"true" pollTime"5000"gt
ltdatabasesgt ltadd name"Northwind"
connectionStringName"Northwind" /gt
lt/databasesgt lt/sqlCacheDependencygt
lt/cachinggt ltsystem.webgt lt/configurationgt
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Using SqlCacheDependency with the Application
Cache
Cache.Insert ("Products", products, new
SqlCacheDependency ("Northwind", "Products")
Database name
Table name
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Using SqlCacheDependency with the Output Cache
lt_at_ OutputCache Duration"60" VaryByParam"None"
SqlDependency"NorthwindProducts" gt
Database name
Table name
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Using SqlCacheDependency with SqlDataSource
ltaspSqlDataSource ID"Countries" RunAt"server"
ConnectionString"serverlocalhostdatabasenorth
wind..." SelectCommand"select distinct
country from customers order by country"
EnableCaching"true" CacheDuration"60000"
SqlCacheDependency"NorthwindCustomers"
/gt ltaspDropDownList ID"MyDropDownList"
DataSourceID"Countries" DataTextField"country"
AutoPostBack"true" RunAt"server" /gt
Database name
Table name
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SQLCacheDependency
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Cache Configuration

• ltcachegt
• Enable/disable application cache
• Enable/disable item expiration and more
• ltoutputCachegt, ltoutputCacheSettingsgt
• Enable/disable output caching
• Enable/disable disk-based persistence
• Set maximum size per app and more
• ltsqlCacheDependencygt

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Session Summary

• Data Controls provide a much simpler way to code
• Output cache is real simple and powerful
• A lot of flexibility without any code
• Fragmented cache for partial page cache
• The Future holds integration with SQL Server

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Questions?
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Thanks!

• Please fill out your evaluation form!
• stevef_at_orcsweb.com
• Please put (PDC Karachi in the subject)