Traffic Shaping

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Traffic Shaping

Shaping is a new throttle violation policy. TIBCO API Exchange Gateway is capable of shaping the requests traffic after reaching the throttle metric. By default, TIBCO API Exchange Gateway blocks the throttled request and sends an error response.

When the Shaping feature is enabled for a facade operation request and the request violates the rate throttle metric, the transaction is placed in an internal queue and the transaction state is set to held. When the throttle metric has been reset by the Global Throttle Manager, all the held transactions are released up to the limit for the throttle and the Core Engine continues to process these transactions. This means that all throttle chains are reevaluated when the transaction is released.

For the performance reasons, the Core Engine does not remove the transactions from the Shaping queue after the transactions are processed from the queue. The gateway uses a separate timer to compact the queue to truncate the queue. See QueueCompactionInterval.

If the transactions in this queue time out, the Core Engine processes the request with normal error handling.

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Shaping is only valid for the rate throttles.

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The Shaping feature does not support the custom monitors.

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When the Shaping feature is enabled for a rate throttle and if the rate throttle is applied at the end of a throttle chain, the earlier throttles in the chain are not decremented.

Configuration

To enable Shaping for a facade operation, follow these steps:

1.

Start the Config UI.

2.

Create a new configuration project or select an existing project.

3.

Click ROUTING > Facade Operations tab.

4.

Create a new facade operation or select an existing facade operation.

5.

In the Operation Features field, type Shaping.

6.

Save the configuration changes.

QueueCompactionInterval

Specifies a time interval (in milliseconds) used for cleaning up the shaping queue. The time interval can be set by the following property in ASG_CONFIG_HOME/asg.properties file.

ASG/Throttle/Shaping/QueueCompactionInterval

The default value is 30000(ms).