About exchanges

Article:HOWTO62292  |  Created: 2011-12-13  |  Updated: 2014-05-19  |  Article URL http://www.symantec.com/docs/HOWTO62292
Article Type
How To


Subject


About exchanges

Workflow exchanges are the messages that Workflow-type processes send and receive through SymQ. You can view and manage exchanges in Workflow Explorer.

See About Workflow Explorer.

The different exchange types are as follows:

Alias

Provides an alternate name for an exchange. This exchange is helpful if an exchange that is configured on one Exchange server needs to be accessed from a different server. Use the same alias name on both servers so that a program that is written to access the exchange works regardless of where it runs.

Async

Delivers the messages in an asynchronous manner.

Branching

Delivers the messages to multiple exchanges at the same time. This exchange is one of the exchange types that enables other exchanges to be linked to perform complex actions.

Synchronized

This exchange wraps other exchanges to provide the added feature of ensuring autonomous operations. Use this exchange type if you need to prevent multiple programs from simultaneously accessing the exchange.

Transactional

This exchange wraps around another exchange, and enables transactions-based message delivery and retrieval.

File Exchange

Writes the messages to a file system.

File Writer Exchange

Writes the messages as log items to a file system. Provides the built-in log file cleanup capabilities.

In Memory

In-memory storage.

Local Interceptor Filter

Used internally by Workflow Server.

Mail

Sends the messages through SMTP.

Message Delivery Registration

Used internally by Workflow Server.

Notification Server Event

Used internally by Workflow Server.

Null

Throws away the messages.

Output Writer

Writes the messages to Debug.Out.

Policy Cache

Wraps another exchange to control the messaging cache. It caches messages according to a defined policy. For example, messages can be removed based on the count or the size of the cache. The policy also provides options (least access, oldest, biggest) to determine which message to get rid of first.

Reliable

This exchange wraps other exchanges to provide reliable delivery to a target exchange. It defines a storage exchange and error exchange to maintain messages and make multiple delivery attempts.

Remote Server

Delivers to a remote server by TCP/IP. This exchange is used for access and exchange on a remote Exchange server.

SQL

Stores the messages in a SQL Server database.

Time Based Cache

This exchange wraps other exchanges to control the messaging cache. It caches messages based on the length of time that the message has been in the queue. This exchange is commonly used with the In Memory exchange to purge old messages from the memory based on time.

Compression

This exchange wraps another exchange to provide message compression and decompression.

Exchanges can be internal or external exchanges.

Table: Internal and external exchanges

Exchange

Description

Internal

Can be referred to only by processes and other exchanges in the same application domain and exchange configuration set.

External

Can be referred to by any other exchange in any configuration set using the syntax lme://servername/exchangename.

Exchanges can be template or non-template exchanges.

Table: Template and non-template exchanges

Exchange

Description

Template

An extensible exchange that follows the syntax exchangename-. (All of the template exchanges must end with a dash.)

Template exchanges do not exist as functional exchanges by themselves. You must complete the exchange call with a term after the dash in the template exchange name.

For example, a template file exchange that is called file- must complete the syntax file-contract. In this case, the file- exchange is configured to write messages to a certain location in the file system (such as C:\messages\file-). When the file-contract call comes, the exchange creates the directory C:\messages\file-contract, and it delivers the file.

Non-template

A standard, non-extensible exchange. Non-template exchanges exist as functional exchanges by themselves, and they cannot end with a dash.

Use the exchange name exactly as it appears when you call a non-template exchange.

Exchange messages are part of exchange configurations. Exchange configurations are groups of the exchanges that are based on accessibility, and they help to simplify exchange management. You can group related collections of exchanges in exchange configurations.

The configurations are as follows:

Server

A Server exchange configuration is a computer-specific configuration. Exchange messages of this type exist in Workflow Server Extensions on the SymQ computer instead of only in the executing application domain.

Exchanges in this type of configuration are available for remote access from client computers or other server computers.

lme://servername/exchangename

DefaultLocal

A DefaultLocal exchange configuration is an application-specific configuration. Any DefaultLocal exchange that is instantiated and used exists only in the process that executes it. (The exchange exists only in the local application domain.)

The DefaultLocal configuration type is not a designation of the computer on which the exchange exists. Here the term local refers to the application that executes the exchange, not the computer.

If you create a DefaultLocal exchange message in one instance of the Messaging Console, the message is unavailable in another instance of the console. (It is available if you save the message to an available location, such as the file system.)

See About the Messaging Console .

You can refer to DefaultLocal exchanges without any server syntax.

SpecificLocal

A SpecificLocal configuration is a computer-specific and directory-specific configuration. Exchanges in this configuration can be accessed only by the computer on which they are running. Any application that is running in the specific local directory to which the exchange is attached can also access the exchange.

Warning:

When you install Symantec Workflow, the default exchanges for SymQ are installed. Do not delete these exchanges; Workflow requires them. If you want to change these exchanges, add your own exchanges that override the defaults.

The Exchange Configuration tab lists configurations and the defined exchanges for each configuration. This tab lets you create new configurations and add new exchanges. You can also modify a configuration by adding, editing, or deleting the associated exchanges.

You can add new exchanges to the default configuration or to your own custom configurations. Usually, you only need to add exchanges to the default configuration.

See Changing an exchange configuration type

See Monitoring message exchanges


Legacy ID



v37001664_v66564686


Article URL http://www.symantec.com/docs/HOWTO62292


Terms of use for this information are found in Legal Notices