service broker

If no other messages are ready to be sent, Service Broker returns a dedicated acknowledgement message.

Service Broker also makes it easy to scale your application up or down to accommodate the amount of traffic the application receives.

One way to understand Service Broker is to think of it as a postal service.

Service Broker activation makes it easy to scale up applications as more processing power becomes available.

For the most part, tuning a stored procedure that uses Service Broker is no different from tuning any other stored procedure.

An event generated when Service Broker is unable to retain a received message that should have been delivered to a service in this instance.

Applications that use Service Broker communicate by sending messages to one another as part of a conversation.

Service Broker does not consider a message arriving for a stopped queue to be an error, and does not notify the sender.

This counter reports the total number of bytes sent over the network by Service Broker endpoints and Database Mirroring endpoints.

When Service Broker receives a message for a service, Service Broker inserts the message into the queue for that service.

Each database contains a unique identifier used for routing Service Broker messages to that database.

To help protect message data, Service Broker also allows you to encrypt messages that leave the instance.

When a message arrives for a service, Service Broker places the message in the queue associated with that service.

A specified RECEIVE statement modifies or returns at least one row to a Service Broker queue.

Service Broker endpoints and transport security apply to the instance as a whole rather than to a specific database.

For this purpose, routes that have the same service broker identifier, service name, and network address are considered to be identical.

Each Service Broker message contains a maximum lifetime and a count of the number of times that the message has been forwarded.

Create a route on the service to define the address to which Service Broker sends messages for the service.

However, Service Broker does not give special consideration to mirror addresses when finding matching routes for a conversation.

Network address to which Service Broker sends messages for the remote service.

The type of authentication an instance uses depends on the AUTHENTICATION option for the Service Broker endpoint of each instance.

Contains descriptions of administrative considerations for management of the security for a Service Broker application.

Service Broker allows only one reader at a time to read messages in a conversation group.

If the message type is not specified in a Service Broker SEND command, the system will use the DEFAULT message type.

GO When a conversation ends, Service Broker discards the messages for that conversation.

Service Broker checks the maximum number of queue readers for a queue as part of the activation process.

For efficiency, Service Broker includes message acknowledgements as part of a sequenced message wherever possible.

When a message is received, Service Broker validates the content of the message to ensure that the content is valid for the message type.

Typically an administrator has no routine maintenance tasks related to Service Broker.

That route is the only route in the set of matching routes, and Service Broker chooses that route.

Further, Service Broker does not consider services in that database to be available for receiving messages.

Each message and conversation has a specific type that Service Broker enforces to help developers write reliable applications.

When a conversation is marked delayed, Service Broker performs the matching process again after a time-out period.

For Windows Authentication, this event reports that Service Broker is unable to use Windows authentication.

Service Broker transport security allows you to require authorization for connections to the port.

Service Broker sends an error to the remote side of any open conversations that use the service.

When a message arrives for a service, Service Broker places the message on the queue associated with the service.

Find an exact match for the service name among routes that do not specify a service broker identifier.

A program that uses Service Broker is typically composed of a number of components working together to accomplish a task.

You can do this when the certificate will be used to verify signatures or in Service Broker scenarios that do not require a private key.

Service Broker indicates errors, the end of a conversation, and timer events by sending a message to the service.

For programs within the database, Service Broker starts another copy of the stored procedure specified by the queue.

Help protect your Service Broker applications from malicious attacks and improve the security of your messaging systems.

Contains descriptions of performance considerations for a Service Broker application.

Therefore, Service Broker must be active in the database where the application requests the subscription.

Service Broker sends and receives messages over the network while any endpoint for Service Broker is in the STARTED state.

An Authentication Failure event reports that Service Broker cannot perform authentication for the connection due to an error.

When receiving messages, Service Broker uses the conversation identity and the sequence number of the message to enforce message ordering.

A Service Broker service is the address to which the post office delivers the letters.

Service Broker uses the remote service bindings in the database that begins the conversation to determine the security for the conversation.

Service Broker sends and receives messages over the network while any Service Broker endpoint is in the STARTED state.

Service Broker also performs a message integrity check to help detect message corruption or tampering.

This section describes each of the objects used in a Service Broker application.

Backup and restore procedures for a Service Broker service are integrated with the database in which the service runs.

Service Broker communicates the status of a conversation to an application through messages.

If message forwarding is not on, Service Broker drops the message if the target service does not exist in the local instance.

The sample is implemented because several Windows User Controls and classes necessary to create Service Broker objects.

For example, the service broker might be able to cache the UDDI data to improve the performance of the service provider selection process.

Service Broker chooses a route from among the set of possible routes.

For a Service Broker application that is in production, most day-to-day management occurs as a normal part of database maintenance.

Instead, when the timer expires, the local Service Broker adds a time-out message to the queue for the local service.

In this scenario, Service Broker functions as a framework for a distributed OLTP system.

The amount of memory available for message forwarding is specified as part of the Service Broker endpoint configuration.

For instance, a retail application with multiple sites can use Service Broker to send transaction information to a central data store.

By default, Service Broker attempts to deliver all messages from outside of the instance within the current instance.

Service Broker extends this idea to let applications perform the work in a different instance, or on a different computer.

For services hosted in a different instance, Service Broker dialog security determines the database principal in the remote instance.

This nicely decouples the service provider and consumer, but it requires them to have clear knowledge of the particular service broker.

When a queue is unavailable, Service Broker holds messages for services that use the queue in the transmission queue for the database.

Applications that must use or display information simultaneously from multiple databases can take advantage of Service Broker.

Makes the certificate available to the initiator of a Service Broker dialog conversation.

When you make a copy of the database, you change the broker instance identifier or ensure that Service Broker message delivery is inactive.

Service Broker solves these problems by handling message order, unique delivery, and conversation identification automatically.

If the service for the message does not exist in the local instance, Service Broker marks the conversation DELAYED.

The database contains the Service Broker objects, stored procedures, certificates, users, and outgoing routes for the application.

An application that needs reliable query processing can submit queries by sending messages to a Service Broker service.

This option deactivates Service Broker message delivery, preserving the existing service broker identifier for the database.

Service Broker could not locate a usable certificate for one of the participants in the conversation.

Check the Service Broker endpoint configuration to ensure that the two instances have compatible network security settings.

Service Broker helps developers compose applications from independent, self-contained components called services.

Finally, drop the service definition to ensure that Service Broker no longer accepts messages for the service.

Discusses how Service Broker allows services to communicate reliably regardless of the collation of the databases that host the services.

However, Service Broker does not deliver the End Dialog message to the remote service until the queue becomes available.

This architecture, as shown below in Figure 1, requires three service roles: a service provider, a service client, and a service broker.

A Service Broker endpoint must be created to send and receive messages from outside of the instance.

The owner of this certificate must have CONNECT permissions to the Service Broker endpoint.

If the target service exists in the local instance, Service Broker uses this route and delivers the message to that service.

To install a Service Broker service, the developer gives the administrator a set of installation scripts.

Service Broker message forwarding does not require a forwarding instance to decrypt the forwarded message.

Only Service Broker messages can be exchanged between the databases.

Using the same programming model also allows Service Broker applications to be redeployed without changes to application code.

Service Broker does not deliver new messages to the queue and does not allow an application to receive messages from the queue.

Contains descriptions of the tasks required to install, maintain, and uninstall Service Broker applications.

Service Broker cannot use certificates that are only encrypted with a password.

For this reason, many broker services find it convenient to follow the recommendations in Naming Service Broker Objects.

Intermediate management of event notification data is accomplished automatically through Service Broker queues.

The conversation routes to the address in the route with that Service Broker identifier.

Service Broker uses a certificate owned by this user for communicating with the specified service on the specified contracts.

Notice that Service Broker does not consider membership in Windows roles when checking SEND permissions.

Service Broker encrypts messages transmitted over the network when the conversation uses anonymous security.

The mirrored routes enable Service Broker to transparently redirect conversations to the current principal server instance.

Therefore, Service Broker uses a consistent collation for names, regardless of the collation of the database that hosts the service.

Service Broker uses conversation groups to manage message locking, which helps application developers manage concurrency.

Activating Service Broker networking allows Service Broker to send and receive messages over the network.

The service broker provides and maintains the service registry, although nowadays public registries are not in vogue.

Service Broker solves this problem by associating related conversations in a conversation group.

Service Broker provides a set of performance counters that provide information on its activities.

The service broker is a tool allowing to expose functionality of existing enterprise application as a service.

Service Broker communications are designed around reliable, asynchronous message delivery.

This topic provides general guidelines for designing applications that take advantage of Service Broker.

The requester finds the right service. The service broker will return the location details of the service to the requester.

Activating Service Broker allows messages to be delivered to the database.

Service Broker dialog security provides end-to-end encryption and authorization for conversations between specific services.

This means that if more than one copy of the target service exists in the instance, Service Broker randomly picks the service to target.

Service Broker can send a fragment that contains an entire small message between fragments of a large message.

An event generated to report the status of a transport connection managed by Service Broker.

More specifically, service requesters submit a request to a service broker, which finds the right service from a service provider.

Total number of Service Broker message fragments received by this connection.

As described above, Service Broker delivers messages to a service in the current instance when the matching route specifies.

Service Broker is designed to help you create secure applications.

Integrated queuing means that ordinary database maintenance and administration also include Service Broker.

However, Service Broker provides a sophisticated routing system for handling cases where an application needs more complex behavior.

Service Broker is a new technology for building database-intensive applications that are secure, reliable, and scalable.

Service Broker does not send or receive messages over the network by default.

Service Broker's integrated design provides benefits for application performance and administration.

Service Broker finds a set of possible routes by matching the service name and the service broker identifier.

Displays the name of the Service Broker endpoint.

Service Broker encrypts messages transmitted over the network when the conversation uses full security.

An Authorization Failure event reports that Service Broker denied authorization for the connection.

If a queue does not reach this state for a period of time, Service Broker activates another instance of the application.

When you drop a contract, Service Broker ends any existing conversations that use the contract with an error.

Contains descriptions of how Service Broker identities protects against message misdirection.

This section describes international considerations for applications that use Service Broker.

Instead, the application uses Service Broker to send information about the transaction to applications that perform background processing.

An application that uses Service Broker always receives each message in a conversation exactly once.

Event notifications send information about events to a service broker service.

Service Broker therefore uses the service name to determine the security for the service.

Conversation groups, conversations, and messages form the run-time structure of a Service Broker application.

Since this is the only route in the set of matching routes, Service Broker chooses that route.

Service Broker handles acknowledgement messages; the process is transparent to an application that uses Service Broker.

Total number of Service Broker message fragments sent by this connection.

Learn more about the Service Broker architecture and plan to use it to implement asynchronous messaging for applications.

Denies permissions on a Service Broker contract, message type, remote service binding, route, or service.

For improved reliability, Service Broker routing contains safeguards against routing loops.

This counter reports the number of network connections that Service Broker currently has open.

Service Broker uses the remote service binding to provide dialog security for conversations that target the remote service.

Service Broker does not allow arbitrary groupings of conversations.

Service Broker helps you write highly scalable database applications that are also secure and reliable.

Requires CONTROL permission on the Service Broker contract, message type, remote service binding, route, or service.

To determine when there is work for a queue reader, Service Broker monitors activity on the queue.

This option activates Service Broker message delivery and creates a new service broker identifier for the database.

Contains performance counters that report general Service Broker information.

Service Broker helps developers build scalable, secure database applications.

An event generated when Service Broker determines the routing for a message.

Service Broker prevents this situation from occurring through conversation group locking.

Service Broker routing allows an application that uses Service Broker to move services to different instances.

Changes the availability of a certificate to Service Broker.

Displays the current state of the Service Broker endpoint.

Service Broker remote authorization controls remote access to an individual service.

Describes the permissions required for users in a Service Broker application.

This protocol does not describe the format that Service Broker messages use on the network.

Therefore, the service broker identifier should be unique across all instances on the same network.

A DII client can discover this information at runtime using a service broker that can look up the service's information.

All messages sent by Service Broker are part of a conversation.

Shows the current state of Service Broker message delivery for each database.

To protect the session key while it is stored in the database, Service Broker encrypts the session key with the master key for the database.

The Broker Event Category includes event classes that are produced by the Service Broker.

Service Broker routing relies on a unique identifier in each database to correctly deliver messages.

Service Broker provides message queues the applications use to communicate requests and responses.

To deliver a message, Service Broker holds the message in the transmission queue for the database that sent the message.

Prevents unauthorized databases from sending Service Broker messages to databases in the local instance.

Dialog security must be manually configured according to the Service Broker dialog full-security model.

Check certificates, users, and permissions for Service Broker transport security.

These services are not considered when Service Broker routing locates a destination service within an instance.

Since only one route matches, Service Broker chooses that route for the conversation.

Service Broker routing determines the service that receives the notification messages.

The service providers can use various technologies to declare or register themselves to the service broker.

However, if the target service does not exist in the local instance, Service Broker chooses ExternalRoute.

TCP is the only allowed protocol for Service Broker.

This section discusses the tasks involved in administering a database that hosts a Service Broker application.

Contains performance counters that report information related to Service Broker and database mirroring network activity.

Finally, Service Broker automatically includes an identifier in every message.

Service Broker endpoints can be started, stopped, or disabled.

Service Broker provides performance counters and event notifications to monitor a service.

Service Broker provides a flexible security framework for helping you secure your applications.

SQL Server does not generate this event when Service Broker receives an error message generated by an application.

However, Database Mail does not use Service Broker networking.

Applications that use Service Broker typically rely on Service Broker's guarantee of reliable messaging.

Describes the tasks required to install a Service Broker application on a production server.

Service Broker always uses remote authorization for a secure conversation that does not take place entirely within a SQL Server instance.

For most applications, a simple approach to Service Broker routing works well.

Service Broker automatically handles many of the difficult tasks required to create messaging applications.

To match the behavior of the internal comparison that Service Broker uses to match service names.

Service Broker includes a message type and contract specifically for event notifications.

When you attach or restore a database, the service broker identifier and message delivery status are unchanged by default.

Service Broker is designed to allow multiple queue readers to efficiently receive messages from a queue.

Service Broker contains message integrity checks that detect corrupt messages.

This may indicate that Service Broker message delivery is not activated in the database.

Service Broker ends all conversations in the database with an error.

Service providers publish services to a service broker.

When the original transaction commits, Service Broker delivers the message to the destination service.

However, if the target service does not exist in the local instance, and message forwarding is on, Service Broker chooses ForwardingRoute.

Developers can use Service Broker to easily build distributed and reliable applications.

Dialogs are bidirectional conversations between two Service Broker services.

It next sends service details to the service broker for storage in a repository.

Service Broker security helps to ensure that messages are not misdirected, and helps to protect the data in transit.

Stops Database Mail by stopping the Service Broker objects that the external program uses.

Shows information about Service Broker network connections.

For more information about how Service Broker chooses a route, see Service Broker Routing and Networking.

And the service requestor finds required services via the service broker and binds the services via the service provider.

The following example sets to 7 the maximum number of stored procedure instances that Service Broker starts for this queue.

This section also presents short overview of building applications with Service Broker.

Service Broker uses routes to determine where to deliver messages.

When the queue becomes available, Service Broker delivers the messages in the transmission queue to the service queue.

Notice that Service Broker does not use the Tabular Data Stream protocol.

This example describes the default configuration for Service Broker routing.

Service Broker creates a new conversation group and assigns a new identifier to the conversation group.

This section presents examples of the Service Broker routing process.

Service Broker does not remove expired routes from the database.

Service Broker supports the vision of applications architected as services.

Service Broker applications are made up of Service Broker database objects and one or more applications that use those objects.

If the service does not exist in the instance, Service Broker may return to step 2 and choose another route.

When you start the service again, the Service Broker starts the updated activation stored procedure.

For more information about dialog security, see Service Broker Dialog Security.

Service Broker endpoints set options for the transport protocol.

To send a message, Database Mail adds a request to a Service Broker queue.

In this case, Service Broker creates a new conversation group with the specified identifier.

An event generated when Service Broker sends or receives a message acknowledgement.

Service Broker message forwarding tracks the number of times that a message has been forwarded to protect against endless routing loops.

TABLOCK limits the checks that are performed; DBCC CHECKCATALOG is not run on the database, and Service Broker data is not validated.

Additionally, event notifications are delivered by using Service Broker.

Specifies that Service Broker is enabled for the specified database.

If no contract is specified in the BEGIN DIALOG statement, Service Broker uses the DEFAULT contract.

Service Broker receives the first message on a new conversation started by another service.

The service broker is currently not mainstream and will be covered in a later venue.

Service broker is a role that could be addressed by possibly two companies.

Create a Service Broker endpoint, specifying the port number and the authentication level.

Service Broker does not stop activation stored procedures when there are no messages on the queue.

Service Broker uses these message types for system messages to the application.

Each Service Broker application is a set of tasks that can operate independently.

The DialogTimer message causes Service Broker to start the activation stored procedure for the queue.

The service sets a conversation timer to expire at the desired time; when the timer expires, Service Broker sends a DialogTimer message.

Service Broker conversations use dialog security by default.

Service Broker maintains state for each active conversation.

For more information, see Service Broker Message Forwarding.

Some SOA technologies, like UDDI and WS-Trust, introduce a third role called a service broker.

Starts the Service Broker objects that the external program uses.

The service registry acts as a service broker for Web services.

Service Broker chooses this route even if the local instance contains the service ElsewhereService.

For more information on Service Broker security, see Security Considerations for Service Broker.