Microsoft SQL Server 2008 R2 Unleashed- P200 docx

You use the following code to create the endpoint: CREATE ENDPOINT SSBEndpointI1 STATE = STARTED AS TCP LISTENER_PORT = 4022 -- the default SSB port; TCP-based FOR SERVICE_BROKER ENCRYPT

received within the specified time, the code successfully locks that conversation group

(that is, locks the specified queue for receiving) If not,@ConversationGroupIdisNULL

After this call, the program attempts to receive the next message in the queue by using the

RECEIVEstatement, whose syntax is similar to that of SELECT, except that instead of

speci-fying a table name, you specify a queue name

Next, the code checks the received message type and takes the appropriate action If the

message type is Error, it ends the dialog, reporting the error If the message type is

EndDialog, it simply ends its side of the dialog If it is a catalog change message, it updates

Publication.Productso that the related row in Publication.ProductCatalog(which

associates products with catalogs) now points to the newest data

Just as with the initiator code, the target code first declares its outgoing messages as a

typed XML variable (@AckXml) This helps in making sure that the outgoing message will

be received without error

One issue to be mindful of is that all this code is executing in the scope of a single

trans-action If any part of the code fails, the ROLLBACKstatement rolls back any DML as well as

message sends and receives To test the code, you can execute the following statement:

EXEC Production.ProductModelUpdate 749, ‘A Super Product’

NOTE

You might want to come up with a clever way of populating the body of the responding

Production.CatalogChangeAckQueueReaderstored procedure to deal with the

incom-ing acknowledgment messages sent by the target

Prioritizing Services

The next issue to consider is conversation priority A safe assumption is that some of your

software applications are more important than others Likewise, some of your SSB services

are mission-critical (and should be configurable as such) and others may be only for casual

use You can easily set a numeric priority for these services so that when system resources

are scarce (during periods of high server and network utilization), messages for your

criti-cal applications are processed first

SQL Server 2008 offers a simple syntax for accomplishing this The following example

illustrates how to set the priority to level 1 for messages transmitted from our SSB initiator

(local) service to our target (remote) service:

CREATE BROKER PRIORITY CatChangeInitToTarget

FOR CONVERSATION

SET

(

CONTRACT_NAME =

[//samspublishing.com/SS2008/SSB/Contracts/BasicCatalogChangeContract],

LOCAL_SERVICE_NAME =

[//samspublishing.com/SS2008/SSB/Services/CatalogChangeInitiatorService],

REMOTE_SERVICE_NAME =

N’//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyTarget’,

PRIORITY_LEVEL = 1

)

Next, you need to learn how to set up Service Broker messaging applications to run on

multiple instances of SQL Server

Service Broker Routing and Security

The following sections detail how to set up the Service Broker constructs you need for

your applications to work in a secure, distributed environment

Using Certificates for Conversation Encryption

In Listing 49.4, you might have noticed that you set theENCRYPTION = OFFflag in the

code of the initiator You had to do this because Service Broker relies heavily on

certifi-cate-based encryption If you had left the encryption flag set to its default ofON, your

messages would not have left their transmission queue, and Service Broker would have

raised an error

Service Broker services running on multiple SQL Server instances communicate across the

network via endpoints that are secured using certificates Certificates are the foundation of

secure network communications They are used for securing email (PGP), FTP (S/FTP),

HTTP (SSL), NET assemblies (strong naming), and more The basic premise of certificates

is the use of public key cryptography: When a digital certificate is created, a public key

(shared openly) and a private key (never shared) are created simultaneously via a special

algorithm such as RSA Data to be securely transmitted is first encrypted by the sender,

using the receiver’s public key, acquired either through a registration authority (RA) or

otherwise When the encrypted data is received, the receiver decrypts the data by using its

private key

SQL Server provides the DDL statementCREATE CERTIFICATEfor creating certificates This

statement provides several methods for doing so, but in this chapter you use it only to

create self-signed certificates—that is, certificates signed by their creator, not by a trusted

external authority (such as VeriSign), known as a certificate authority (CA)

Before you create a certificate, you need to create a master key for the masterdatabase

(just as you did with AdventureWorks2008andXCatMgmt) that can be used to protect the

private keys you’ll create You also need to create certificates on masterfor use with the

endpoint you need (as described later in this section) Note that you have to perform this

step and subsequent steps on all the instances of SQL Server that will be communicating

via Service Broker In the sample code, by convention, the objects created on the first

instance all terminate with the string I1, and in the second instance, they terminate with

I2 In addition, we refer to the first SQL Server instance as I1and the second as I2

The following T-SQL creates a master key in the masterdatabase:

USE master

GO

CREATE MASTER KEY ENCRYPTION BY PASSWORD = ‘masterI1’

Now you can create your first certificate in masteronI1 (Note that SUBJECTis a metadata

field defined in the certificate standard X.509.) Here’s how you do it:

CREATE CERTIFICATE SSBMasterCertI1

WITH SUBJECT = ‘SSBMasterCertOnInstance1’,

START_DATE = ‘2008-10-02 07:30:35’;

Note: The start date must not be in the future,

or the certificate is not useful

Next, you need to create a TCP endpoint that enables Service Broker in I1to

communi-cate with Service Broker in I2 (The CREATE ENDPOINTsyntax is shown in Chapter 54,

“Managing Linked and Remote Servers,” for use in creating web services.) This endpoint

uses the keys in the certificate you just created to communicate securely You use the

following code to create the endpoint:

CREATE ENDPOINT SSBEndpointI1

STATE = STARTED

AS TCP (LISTENER_PORT = 4022) the default SSB port; TCP-based

FOR SERVICE_BROKER

(ENCRYPTION = REQUIRED, AUTHENTICATION = CERTIFICATE SSBMasterCertI1)

GO

GRANT CONNECT ON ENDPOINT::SSBEndpointI1

TO [SSBTestUserName]

ForI2to encrypt messages using the public key that resides in MasterCertI1, that public

key must be exported from the database to a file and then imported into a new certificate

onI2 You can use the newBACKUP CERTIFICATEcommand to accomplish the export to

file, and then you can perform the same steps on I2to import MasterCertI1’s public key

into a matching certificate:

BACKUP CERTIFICATE SSBMasterCertI1 TO FILE = ‘c:\temp\MasterCertI1_PK.cer’

Now you need to switch over to the second SQL Service instance and run the following

code:

USE master

GO

CREATE MASTER KEY ENCRYPTION BY PASSWORD = ‘masterI2’

GO

CREATE CERTIFICATE SSBMasterCertI2

WITH SUBJECT = ‘MasterCertOnInstance2’,

START_DATE = ‘2008-10-02 07:30:35’;

GO

CREATE ENDPOINT SSBEndpointI2

STATE = STARTED

AS TCP (LISTENER_PORT = 4022)

FOR SERVICE_BROKER

(ENCRYPTION = REQUIRED, AUTHENTICATION = CERTIFICATE SSBMasterCertI2)

GO

GRANT CONNECT ON ENDPOINT::SSBEndpointI2

TO [SSBTestUserName]

GO

BACKUP CERTIFICATE SSBMasterCertI2

TO FILE = ‘c:\temp\SSBMasterCertI2_PK.cer’

GO

CREATE CERTIFICATE SSBMasterCertI1

AUTHORIZATION [SSBTestUserName]

FROM FILE = ‘C:\temp\SSBMasterCertI1_PK.cer’

The last statement in this code creates a certificate on I2that has the same name and

contains the same public key as SSBMasterCertI1 It also performs an essential function: it

assigns that public key to SSBTestUserNameby using theAUTHORIZATIONkeyword

Now you can return to the first instance to do the same there, using SSBMasterCertI2’s

public key:

CREATE CERTIFICATE SSBMasterCertI2

AUTHORIZATION [SSBTestUserName]

FROM FILE = ‘C:\temp\SSBMasterCertI2_PK.cer’

Note that you set up SSBTestUserNameas a domain user and then add this user as a login

withdb_ownerpermissions on both instances You don’t need to create SSBTestUserName

inXCatMgmtbecause this user is already (or should be) there For purposes of this

discus-sion, you can assume that both instances can use the path c:\temp

The next step is to create a new database on I2calledXBikeDistribution The concept

behind this database is that XBikeDistributionis a subscriber to one of the catalogs

published by XCatMgmt When a product in that catalog changes, XBikeDistribution

needs to know about it You can use the following code to create this database so that it is

as lean as possible:

USE master

GO

CREATE DATABASE XBikeDistribution

WITH TRUSTWORTHY ON

GO

ALTER DATABASE XBikeDistribution SET ENABLE_BROKER

GO

USE XBikeDistribution

GO

CREATE MASTER KEY ENCRYPTION BY PASSWORD = ‘XBikeDistributionPW’

GO

CREATE SCHEMA Cataloging

CREATE TABLE Cataloging.CatalogSimple

(

CatalogId int IDENTITY(1,1) PRIMARY KEY,

CatalogXml xml NOT NULL,

LastUpdateDate datetime DEFAULT GETDATE()

)

GO

CREATE USER [SSBTestUserName]

The next step is to add the XML schema collection you used in previous examples

(GenericAcknowledgementSchema; found in Listing 49.2) to XBikeDistribution Then you

need to set up certificates for use in the Service Broker dialogs that will take place between

the catalog change service running in XCatMgmtand a new service you need to set up in

XBikeDistribution On I2, you run the following code to set up a certificate for use in

Service Broker conversations:

CREATE CERTIFICATE SSBDialogCertI2

WITH SUBJECT = ‘SSBDialogCertOnInstance2’,

START_DATE = ‘2008-10-02 07:30:35’

ACTIVE FOR BEGIN_DIALOG = ON;

GO

BACKUP CERTIFICATE SSBDialogCertI2

TO FILE = ‘c:\temp\SSBDialogCertI2_PK.cer’

Now you need to switch back to I1, change to XCatMgmt, and create two more certificates,

one for each side of the exchange:

USE XCatMgmt

GO

CREATE CERTIFICATE SSBDialogCertI1

WITH SUBJECT = ‘SSBDialogCertOnInstance1’,

START_DATE = ‘2008-10-02 07:30:35’

ACTIVE FOR BEGIN_DIALOG = ON;

GO

BACKUP CERTIFICATE SSBDialogCertI1

TO FILE = ‘c:\temp\SSBDialogCertI1_PK.cer’

GO

CREATE CERTIFICATE SSBDialogCertI2

AUTHORIZATION [SSBTestUserName]

FROM FILE = ‘C:\temp\SSBDialogCertI2_PK.cer’;

Note that the second certificate in this code contains the public key you just created and

exported to file in SSBDialogCertI2

Now you need to return to I2and import the public key in SSBDialogCertI1and

associ-ate it with SSBTestUserName:

CREATE CERTIFICATE SSBDialogCertI1

AUTHORIZATION [SSBTestUserName]

FROM FILE = ‘C:\temp\SSBDialogCertI1_PK.cer’;

By the time you’re done creating all these certificates, you should have the following .cer

files in your directory: SSBMasterCertI1_PK.cer,SSBMasterCertI2_PK.cer,

SSBDialogCertI2_PK.cer, and SSBDialogCertI1_PK.cer By now, the pattern of certificate

creation and public key user association should be quite clear

The next step is to set up the Service Broker constructs You need to start on I2in

XBikeDistributionbecause it has no constructs yet First, you create the

GenericAcknowledgementSchemaXML schema collection in XBikeDistribution, as shown

earlier in Listing 49.2 Note that in this Service Broker conversation, a service in XCatMgmt

plays the role of initiator, and a service in XBikeDistributionis the target (Because

you’ve seen this all before, the following examples lump a lot of the DDL together.)

Next, you need to switch to I2and run the code in Listing 49.6

LISTING 49.6 T-SQL for Creating All the Service Broker Constructs on a Second SQL Server

Instance

USE XBikeDistribution

GO

CREATE MESSAGE TYPE

[//samspublishing.com/SS2008/SSB/MessageTypes/CatalogChangeNotifySimple]

AUTHORIZATION [SSBTestUserName] VALIDATION = WELL_FORMED_XML;

GO

CREATE MESSAGE TYPE

[//samspublishing.com/SS2008/SSB/MessageTypes/GenericAck]

AUTHORIZATION [SSBTestUserName] VALIDATION = VALID_XML

WITH SCHEMA COLLECTION GenericAcknowledgementSchema

GO

CREATE CONTRACT

[//samspublishing.com/SS2008/SSB/Contracts/SimpleCatalogNotifyContract]

AUTHORIZATION [SSBTestUserName]

(

[//samspublishing.com/SS2008/SSB/MessageTypes/CatalogChangeNotifySimple]

SENT BY INITIATOR,

[//samspublishing.com/SS2008/SSB/MessageTypes/GenericAck]

SENT BY TARGET

)

GO

CREATE PROC Cataloging.CatalogChangeNotifyQueueReader

AS

GO

CREATE QUEUE Cataloging.CatalogChangeNotifyReceiveQueue

WITH

STATUS = ON,

ACTIVATION

(

STATUS = ON,

PROCEDURE_NAME = Cataloging.CatalogChangeNotifyQueueReader,

MAX_QUEUE_READERS = 10,

EXECUTE AS ‘SSBTestUserName’

)

GO

CREATE SERVICE

[//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyTarget]

ON QUEUE Cataloging.CatalogChangeNotifyReceiveQueue

( [//samspublishing.com/SS2008/SSB/Contracts/SimpleCatalogNotifyContract] )

GO

CREATE ROUTE

[//samspublishing.com/SS2008/SSB/Routes/RouteToCatalogChangeNotifyInitator]

WITH

SERVICE_NAME =

‘//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyInitiator’,

ADDRESS = ‘TCP://192.168.22.5:4022’;

GO

CREATE REMOTE SERVICE BINDING

[//samspublishing.com/SS2008/SSB/RSBindings/RSBForCatalogChangeNotifyInitator]

TO SERVICE

‘//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyInitiator’

WITH USER = [SSBTestUserName],

ANONYMOUS = OFF

GO

GRANT SEND ON

SERVICE::[//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyTarget]

TO [SSBTestUserName]

Listing 49.7 contains all the DDL you need to create the complementary Service Broker

objects in XCatMgmtonI1

LISTING 49.7 T-SQL for Creating All the Service Broker Constructs on the First SQL Server

Instance

USE XCatMgmt

GO

CREATE MESSAGE TYPE

[//samspublishing.com/SS2008/SSB/MessageTypes/CatalogChangeNotifySimple]

AUTHORIZATION [SSBTestUserName] VALIDATION = WELL_FORMED_XML;

GO

CREATE CONTRACT

[//samspublishing.com/SS2008/SSB/Contracts/SimpleCatalogNotifyContract]

AUTHORIZATION [SSBTestUserName]

(

[//samspublishing.com/SS2008/SSB/MessageTypes/CatalogChangeNotifySimple]

SENT BY INITIATOR,

[//samspublishing.com/SS2008/SSB/MessageTypes/GenericAck]

SENT BY TARGET

)

GO

CREATE PROC Publication.CatalogChangeNotifyAckQueueReader

AS

GO

CREATE QUEUE Publication.CatalogChangeNotifyAckQueue

WITH

STATUS = ON,

ACTIVATION

(

STATUS = ON,

PROCEDURE_NAME = Publication.CatalogChangeNotifyAckQueueReader,

MAX_QUEUE_READERS = 10,

EXECUTE AS ‘SSBTestUserName’

)

GO

CREATE SERVICE

[//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyInitiator]

ON QUEUE Publication.CatalogChangeNotifyAckQueue

( [//samspublishing.com/SS2008/SSB/Contracts/SimpleCatalogNotifyContract] )

GO

CREATE ROUTE

[//samspublishing.com/SS2008/SSB/Routes/RouteToCatalogChangeNotifyTarget]

WITH

SERVICE_NAME =

‘//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyTarget’,

ADDRESS = ‘TCP://192.168.22.6:4022’;

GO

CREATE REMOTE SERVICE BINDING

[//samspublishing.com/SS2008/SSB/RSBindings/RSBForCatalogChangeNotifyTarget]

TO SERVICE

‘//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyTarget’

WITH USER = [SSBTestUserName],

ANONYMOUS = OFF

GO

GRANT SEND ON

SERVICE::[//samspublishing.com/SS2008/SSB/Services/CatalogChangeNotifyInitiator]

TO [SSBTestUserName]

If you look closely at Listings 49.6 and 49.7, you see that they introduce two new Service

Broker constructs: routes and remote service bindings

Building Routes to Map Conversations Between SQL Server Instances

Routes are used to map a Service Broker service to a TCP address for use when conversing

between different SQL Server instances They provide a useful level of abstraction because

the address of a route can be changed without having to change any of the constructs that

depend on it In this way, it is possible to change a route and, as long as the message

types, required XML schema collections, contracts, queues, and services exist in the

data-bases on the machines involved, only the route needs to be updated Routes can also be

used when only a single SQL Server instance is involved so that it can easily be changed to

work when a new instance comes into play

NOTE

For the routes in this example to work, the TCP port specified earlier in CREATE

END-POINT(port 4022) must be open on any firewalls involved

The routes created in Listings 49.6 and 49.7 are thus necessary because the initiator needs

to be able to locate the target service to send messages, and the target service needs to be

able to do the same

Creating Remote Service Bindings for Conversations

When initiating a conversation with a service on a nonlocal SQL Server instance, you

need to create a remote service binding A remote service binding associates a local database

user with a remote service When messages are transmitted between the instances, Service

Broker encrypts them, using the public key of the local user’s certificate They are then

decrypted on the other end, using the private key Because you have created matching

pairs of certificates and associated them with the user in the masterdatabase and in all

participating databases on both instances (and you have also turned off anonymous

access), you can be certain that communications will happen securely over the network

A Final Note on the Sample System

If you like, you can create the initiator and target service programs for the final example

in this chapter For example, you could create an update trigger (as the initiator) on

XCatMgmt.Publication.ProductCatalogthat sends a CatalogChangeNotifySimple

well-formed XML message to

XBikeDistribution.Cataloging.CatalogChangeNotifyReceiveQueue You fill in the body

of the target’s activated procedure

XBikeDistribution.Cataloging.CatalogChangeNotifyQueueReaderto receive these

messages and reply by sending a message of type GenericAckto the existing

Production.CatalogChangeAckQueue Remember that you need to acquire the

service_broker_guidof the remote SQL Server instance’s Service Broker instance to send

messages successfully Also, you need to be sure to set the ENCRYPTIONflag to ON(the

default) when callingBEGIN DIALOG CONVERSATION

Troubleshooting SSB Applications with

ssbdiagnose.exe

SQL Server 2008 comes with a new command-line application,ssbdiagnose.exe You use

this advanced utility to monitor SSB conversations or to check application configuration

status, both across databases and between computers It supports a variety of authentication

and configuration options and generates either plain text or XML as its output

The general syntax for ssbdiagnose.exehas three parts:

Output format and error level

Connection information

Application-specific settings

You can leverage the full syntax of ssbdiagnose.exeby simply executing it from the

command line with no options (it is located in the folder [SQL Server installation

root]\[version number]\Tools\Binn) To run it, open a command window (run the

CMD.exeprogram) and then navigate to your installation location using the CDcommand

As an exercise, you can execute any of the examples that follow

In the following example, you connect to the current SSB application (as developed in

Listings 49.1 through 49.7) and check on the services’ configuration status Remember

that the application lives in two databases (AdventureWorks2008andXCatMgmt), so you

need to provide parameters to check on both sides of the service contract Because the

service and contract names are quite long, we suggest enclosing the command-line

contents in a batch file and running it from there

Execute the following command, substituting connection credentials with those

appropri-ate for your environment:

SSBDiagnose.exe

-U SSBTestUserName -P SSBTestUserName CONFIGURATION FROM SERVICE

“//samspublishing.com/SS2008/SSB/Services/CatalogChangeInitiatorService”

-S localhost\SQL08 -d AdventureWorks2008 TO SERVICE

“//samspublishing.com/SS2008/SSB/Services/CatalogMaintenanceService”

-S localhost\SQL08 -d XCatMgmt ON CONTRACT

“//samspublishing.com/SS2008/SSB/Contracts/BasicCatalogChangeContract”

If you’ve executed all the sample code and listings in this chapter, you should see no

errors in the ssbdiagnose.exeoutput For troubleshooting, refer to the next section to

learn how to explore the system catalogs for SSB