Sofia, Bulgaria | 9-10 October SQL Server 2005 Query Notifications in ASP.NET 2.0 & ADO.NET 2.0 Julie Lerman The Data Farm Julie Lerman The Data Farm

Sofia, Bulgaria | 9-10 OctoberSofia, Bulgaria | 9-10 October

SQL Server 2005 Query Notifications

SQL Server 2005 Query Notifications

in ASP.NET 2.0 & ADO.NET 2.0

in ASP.NET 2.0 & ADO.NET 2.0

Julie Lerman

The Data Farm

Julie Lerman

The Data Farm

Sofia, Bulgaria | 9-10 October

About MeAbout Me

● Independent Software Developer

● 20+ years development experience

● Microsoft .NET MVP

● ASPInsider

● INETA Speaker

● Various publications & conferences● Blogs: thedatafarm.com/blog blog.ziffdavis.com/devlife

● Founder and leader of Vermont .NET

● Vermont Software Developer Alliance Board

● Independent Software Developer

● 20+ years development experience

● Microsoft .NET MVP

● ASPInsider

● INETA Speaker

● Various publications & conferences● Blogs: thedatafarm.com/blog blog.ziffdavis.com/devlife

● Founder and leader of Vermont .NET

● Vermont Software Developer Alliance Board


AgendaAgenda

● SQL Server 2005 Query Notifications

● ADO.NET 2.0 Notifications

● ASP.NET 2.0 Cache Invalidation

● SQL Server 2005 Query Notifications

● ADO.NET 2.0 Notifications

● ASP.NET 2.0 Cache Invalidation


Query NotificationsQuery Notifications

● New feature in SQL Server 2005

● Works with SQL Server Service Broker

● Enables asynchronous database apps

● Uses queues as first class objects

● T-SQL can interact with the queues

● Transactional Message Processing

● Reliable Distributed Processing

● *Not* Notification Services

● New feature in SQL Server 2005

● Works with SQL Server Service Broker

● Enables asynchronous database apps

● Uses queues as first class objects

● T-SQL can interact with the queues

● Transactional Message Processing

● Reliable Distributed Processing

● *Not* Notification Services


How they workHow they work

SQL Server

Data

SQL Server Service Broker

MessageQueueServices

Listener

ChangeDetection forrowset DML

Application

Query from Client

NotificationFlag

SQL Server 2005


UsesUses● Queries that do not change frequently

● Queries that need to stick around for a while

Look-up Tables

● When details of change are unimportant● Only reports that “something has changed”

● Web Applications● Page level or middle tier

● Windows Apps● Server tier (e.g. remoting or web services)

● Client side: no more than 10 concurrent users

● Queries that do not change frequently

● Queries that need to stick around for a while

Look-up Tables

● When details of change are unimportant● Only reports that “something has changed”

● Web Applications● Page level or middle tier

● Windows Apps● Server tier (e.g. remoting or web services)

● Client side: no more than 10 concurrent users


Query RulesQuery Rules● Use explicit columns in command text

● Required for Change Detection internals

● “select *” will not work

● Use two-part names to reference tables● e.g.: owner.tablename or schema.tablename

● NO!● UNION, Outer Joins, TOP, DISTINCT,

COUNT*, aggregates (AVG, MAX, etc.), INTO, more... (see resources for list)

● TEMP, table variables, multiple views, system tables/views, queues, more....

● Use explicit columns in command text● Required for Change Detection internals

● “select *” will not work

● Use two-part names to reference tables● e.g.: owner.tablename or schema.tablename

● NO!● UNION, Outer Joins, TOP, DISTINCT,

COUNT*, aggregates (AVG, MAX, etc.), INTO, more... (see resources for list)

● TEMP, table variables, multiple views, system tables/views, queues, more....


SQL Server RulesSQL Server Rules● Enable Service Broker on database

● SQL Server security has this off by defaultALTER DATABASE mydb SET ENABLE_BROKER

● Database Compatibility Level = 90● Older databases (e.g. pubs) might be 80 or lower

● sp_dbcmptlevel or Database/Properties/Options

● Permissions for non-admins● One time setup per account

● Enable Service Broker on database● SQL Server security has this off by default

ALTER DATABASE mydb SET ENABLE_BROKER

● Database Compatibility Level = 90● Older databases (e.g. pubs) might be 80 or lower

● sp_dbcmptlevel or Database/Properties/Options

● Permissions for non-admins● One time setup per account


Non-Admin setup TSQLNon-Admin setup TSQL

● sql_dependencey_subscriber role in SQL Server● EXEC sp_addrole 'sql_dependency_subscriber’

● Permissions needed for users to Start● GRANT CREATE PROCEDURE to startUser ● GRANT CREATE QUEUE to startUser ● GRANT CREATE SERVICE to startUser ● GRANT REFERENCES on CONTRACT::

[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification] to startUser

● GRANT VIEW DEFINITION TO startUser

● Permissions needed for users to Execute

● GRANT SELECT to executeUser ● GRANT SUBSCRIBE QUERY NOTIFICATIONS TO executeUser ● GRANT RECEIVE ON QueryNotificationErrorsQueue TO executeUser ● GRANT REFERENCES on CONTRACT::

[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification] to executeUser

● EXEC sp_addrolemember 'sql_dependency_subscriber', 'executeUser'

● sql_dependencey_subscriber role in SQL Server● EXEC sp_addrole 'sql_dependency_subscriber’

● Permissions needed for users to Start● GRANT CREATE PROCEDURE to startUser ● GRANT CREATE QUEUE to startUser ● GRANT CREATE SERVICE to startUser ● GRANT REFERENCES on CONTRACT::

[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification] to startUser

● GRANT VIEW DEFINITION TO startUser

● Permissions needed for users to Execute

● GRANT SELECT to executeUser ● GRANT SUBSCRIBE QUERY NOTIFICATIONS TO executeUser ● GRANT RECEIVE ON QueryNotificationErrorsQueue TO executeUser ● GRANT REFERENCES on CONTRACT::

[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification] to executeUser

● EXEC sp_addrolemember 'sql_dependency_subscriber', 'executeUser'

*Sushil Chordia on blogs.msdn.com/dataworks


ADO.NET 2.0 IntegrationADO.NET 2.0 Integration

● SqlDependency class[System.Data.SqlClient namespace]

● Uses SqlQueryNotificationService in MSDB database

● SqlNotificationRequest class[System.Data.Sql namespace]

● Requires you to write your own listener

● Works with DataReaders & DataAdapters

● SqlDependency class[System.Data.SqlClient namespace]

● Uses SqlQueryNotificationService in MSDB database

● SqlNotificationRequest class[System.Data.Sql namespace]

● Requires you to write your own listener

● Works with DataReaders & DataAdapters


DemonstrationDemonstration

SQLDependency:Basic FunctionalitySQLDependency:

Basic Functionality


SqlDependency StepsSqlDependency Steps1. SqlDependency.Start(Connection)

• Only needed once per app

• e.g. in Global.ASAX

2. Create SqlCommand

3. Create SqlDependency

4. Attach SqlDependency to SqlCommand

5. Execute SqlCommand

6. Create delegate to listen for OnChange

7. and/or SqlDependency.Changed property

1. SqlDependency.Start(Connection)

• Only needed once per app

• e.g. in Global.ASAX


3. Create SqlDependency

4. Attach SqlDependency to SqlCommand


6. Create delegate to listen for OnChange

7. and/or SqlDependency.Changed property


The PlumbingThe Plumbing

SQL ConnectionSqlDepStart

Query w/ Depend

DataContainer

Service Broker•creates queue•creates service•creates sproc for cleanup

Data Change

“something

changed!”

Application SQL Server 2005


SqlDependency.StartSqlDependency.Start

● Creates static non-pooled connection

● Creates default queues and services

● Optional

● Create your own custom services & queues in SQL Server and pass the queue name as a parameter with Start

● Creates static non-pooled connection

● Creates default queues and services

● Optional

● Create your own custom services & queues in SQL Server and pass the queue name as a parameter with Start

SqlDependency.Start(connString)

or

SqlDependency.Start(connString,”myQueue”,”myService”)


SqlNotificationEventArgsSqlNotificationEventArgs

● Notification is not always about a change

● Type

● Source

● Info

● One of 18 Enums can be returned● Update

● Invalid: Query does not follow rules

● Options: Not all SQL Server options are set

● more…

● Notification returns immediately for problems

● Notification is not always about a change

● Type

● Source

● Info

● One of 18 Enums can be returned● Update

● Invalid: Query does not follow rules

● Options: Not all SQL Server options are set

● more…

● Notification returns immediately for problems


In the Middle TierIn the Middle Tier

● Cache Data at the Application Level

● All client sessions get data from that cache

● Notification triggers the cache to update

● Cache Data at the Application Level

● All client sessions get data from that cache

● Notification triggers the cache to update



SqlDependency in the Middle TierSqlDependency in the Middle Tier


SqlNotificationRequestSqlNotificationRequest

● Lower level than SqlDependency

● Does not use default queue in SQL Server

● Custom Service and Queue must be created in SQL Server in advance

● Does not require an application wide “Start”

● Definitely for the middle tier

● Lower level than SqlDependency

● Does not use default queue in SQL Server

● Custom Service and Queue must be created in SQL Server in advance

● Does not require an application wide “Start”

● Definitely for the middle tier


SqlNotificationRequest StepsSqlNotificationRequest Steps

1. Create QUEUE & SERVICE in SS2005


3. Create SqlNotificationRequest

4. Point request to QUEUE & SERVICE

5. Attach SqlNotificationRequest to SqlCommand


7. Run WAITFOR Query

8. Handle results of WAITFOR

1. Create QUEUE & SERVICE in SS2005


3. Create SqlNotificationRequest

4. Point request to QUEUE & SERVICE

5. Attach SqlNotificationRequest to SqlCommand


7. Run WAITFOR Query

8. Handle results of WAITFOR


Create Queue & ServiceCreate Queue & Service

CREATE QUEUE myqueue

CREATE SERVICE myservice ON QUEUE myqueue ([http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification])

CREATE QUEUE myqueue

CREATE SERVICE myservice ON QUEUE myqueue ([http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification])



SqlNotificationRequestSqlNotificationRequest


Cache Invalidation 1.xCache Invalidation 1.x● Invalidate triggers with:

● File Change● Key Change (pointing to different

cache)● Time Based

● Database change invalidation● Complicated trickery● Can be done with bells and whistles

involving SQL Server TRIGGERS and file dependency

● Invalidate triggers with:● File Change● Key Change (pointing to different

cache)● Time Based

● Database change invalidation● Complicated trickery● Can be done with bells and whistles

involving SQL Server TRIGGERS and file dependency


Cache Invalidation 2.0Cache Invalidation 2.0

● SqlCacheDependency class● System.Web.Caching namespace

● Inherits from System.Web.Caching.CacheDependency

● Internals similar to SqlDependency

● Plugs into the Output Cache

● Two methods

● Server-side code using SqlCacheDependency

● Client side within <% OutputCache > directive

● SqlCacheDependency class● System.Web.Caching namespace

● Inherits from System.Web.Caching.CacheDependency

● Internals similar to SqlDependency

● Plugs into the Output Cache

● Two methods

● Server-side code using SqlCacheDependency

● Client side within <% OutputCache > directive



SqlCacheDependencySqlCacheDependency


SqlCacheDependency StepsSqlCacheDependency Steps

Similar to SqlDependency

1. SqlDependency.Start


3. Create SqlCacheDependency

4. Attach SqlCacheDependency to command

5. Execute Command

6. Add SqlCacheDependency to the Cache of the Response object

7. Set Cache properties

Similar to SqlDependency

1. SqlDependency.Start


3. Create SqlCacheDependency

4. Attach SqlCacheDependency to command

5. Execute Command

6. Add SqlCacheDependency to the Cache of the Response object

7. Set Cache properties


<% OutputCache…><% OutputCache…>● Remember the SqlDependency.Start

● Can be in global.asax System.Data.SqlClient.SqlDependency.Start(ConfigurationMan

ager.ConnectionStrings[“myConn”].ConnectionString)

● SqlDependency=“CommandNotification”● Flags ASP.NET to use SQL Server 2005 Query

Notification● Applies to all valid queries related to page

● SqlDependency= anything else● Will use polling method to check for changes to

database● Requires additional setup in web.config &

aspnet_regsql.exe command line tool● Works with SS2005, SS2000, SS7

● Remember the SqlDependency.Start● Can be in global.asax System.Data.SqlClient.SqlDependency.Start(ConfigurationMan

ager.ConnectionStrings[“myConn”].ConnectionString)

● SqlDependency=“CommandNotification”● Flags ASP.NET to use SQL Server 2005 Query

Notification● Applies to all valid queries related to page

● SqlDependency= anything else● Will use polling method to check for changes to

database● Requires additional setup in web.config &

aspnet_regsql.exe command line tool● Works with SS2005, SS2000, SS7



<% OutputCache…><% OutputCache…>


ConclusionConclusion

● Query Notification is a powerful feature for ASP.NET Applications

● Best target is read-mostly lookup tables

● Use in middle with ADO.NET classes

● Use at page level with ASP.NET classes

● Query Notification is a powerful feature for ASP.NET Applications

● Best target is read-mostly lookup tables

● Use in middle with ADO.NET classes

● Use at page level with ASP.NET classes


Contact InfoContact Info

Julie [email protected]

www.thedatafarm.com

www.thedatafarm.com/blog

Julie [email protected]

www.thedatafarm.com

www.thedatafarm.com/blog


ResourcesResources

Query Notifications in ADO.NET 2.0 Bob Beauchemin, MSDN Online April 2005

What’s New in ADO.NET 2.0 Julia Lerman, MSDN Magazine April 2005Caching Improvements in ASP.NET WhidbeyG. Andrew Duthie, MSDN Online Feb 2004

Improved Caching in ASP.NET 2.0 Stephen Walther, MSDN Online, June 2004

Asynchronous Command Execution in ADO.NET 2.0 Pablo Castro, MSDN Online, July 2004

ADO.NET 2.0 and System.Xml v.2.0 – The Beta Version Alex Homer, Dave Sussman, Mark Fussell Addison-Wesley, April 2005

Query Notifications in ADO.NET 2.0 Bob Beauchemin, MSDN Online April 2005

What’s New in ADO.NET 2.0 Julia Lerman, MSDN Magazine April 2005Caching Improvements in ASP.NET WhidbeyG. Andrew Duthie, MSDN Online Feb 2004

Improved Caching in ASP.NET 2.0 Stephen Walther, MSDN Online, June 2004

Asynchronous Command Execution in ADO.NET 2.0 Pablo Castro, MSDN Online, July 2004

ADO.NET 2.0 and System.Xml v.2.0 – The Beta Version Alex Homer, Dave Sussman, Mark Fussell Addison-Wesley, April 2005


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Sofia, Bulgaria | 9-10 October SQL Server 2005 Query Notifications in ASP.NET 2.0 & ADO.NET 2.0 Julie Lerman The Data Farm Julie Lerman The Data Farm