Configuring the Adapter for Load Balancing Using RVCMQ
TIBCO Adapter for COM uses the TIBCO Rendezvous-supported RVCMQ sessions to achieve load balancing using distributed queues. Load balancing is achieved at the service component level. To ensure load balancing across machines, the same COM Server must be installed on multiple machines, and each of those machines should run the service instance configured using the RVCMQ session.
The TIBCO Rendezvous daemon process delivers a message to only one service
instance. TIBCO Rendezvous balances the load between all the running service instances (RVCMQ Sessions) that share the same CMQ Name. Therefore, when one instance of the service is busy in processing a message, the TIBCO Rendezvous daemon process will assign the task to another service instance. The interceptor component does not directly contribute to the overall load balancing mechanism. However, it should be configured to support load balancing at the service level.
To configure the interceptor and service for load balancing using RVCMQ.
- Create a project using TIBCO Designer.
- Use the
Import Metadata
option under the Import Schema
tab, in TIBCO Designer to import the COM type library information into the project file. The Import Schema
tab is available when you select the Advanced Services
folder in the project panel.
Configuring Interceptor Component
To configure the interceptor:
- Create an adapter instance for the interceptor. You can create a Request Response Invocation or Publication service that uses the
Certified
quality of service. Specify the subject name on which this service will send the request message.
- Choose a schema for this service.
Configuring Service Component
To configure the service:
- Create an adapter instance for the service. You can create a Request-Response Server or Subscription service that uses the
Distributed
quality of service. Specify the subject name on which this service will listen for messages.
- Choose a schema for this service.
- Configure a CMQ session:
- Specify a CMQ Name. Make sure that the CMQ session for all the adapter instances participating in Load Balancing have the same
CMQ Name
value.
- Specify the Scheduler Activation value. This is a required value that indicates the number of milliseconds within which, if a heartbeat signal is not received by all the queue members, the queue member with the greatest scheduler weight takes its place as the new scheduler. The value of all the queue member sessions should have the same value for this parameter.
- Specify the Scheduler Heartbeat value. This is a required value that indicates the time (in milliseconds) between two heartbeat signals sent by the scheduler. All the queue member sessions should have the same value for this parameter.
- Specify the Scheduler Weight value. This field represents the ability of this session to fulfill the role of a scheduler, relative to other members of the same queue. The higher the weight, the more the precedence for becoming the scheduler.
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Changes to the client or the server implementation are not required to use the RVCMQ feature. Configuring the sessions and endpoints will enable the adapter to participate in an RVCMQ environment.
For more information on the RVCMQ/load balancing feature, see the TIBCO Adapter SDK documentation.
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TIBCO Adapter™ for COM User’s Guide
Software Release 5.3,
September 2005
Copyright © TIBCO Software Inc. All rights reserved
www.tibco.com
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