RabbitMQ Nack Adapter

Introduction

The TIBCO StreamBase® Output Adapter for RabbitMQ Nack allows the system to respond to a message with a negative acknowledgement (NACK) back to the server. A negative acknowledgement tells the server that the message was not processed by this consumer and should optionally be requeued on the server to send to another consumer. The consumer that produces the message tuple must have its Auto Acknowledge message property disabled for this adapter to have affect.

Adapter Properties

This section describes the properties you can set for this adapter, using the various tabs of the Properties view in StreamBase Studio.

General Tab

Name: Use this required field to specify or change the name of this instance of this component, which must be unique in the current EventFlow module. The name must contain only alphabetic characters, numbers, and underscores, and no hyphens or other special characters. The first character must be alphabetic or an underscore.

Operator: A read-only field that shows the formal name of the operator.

Start with application: If this field is set to Yes (default) or to a module parameter that evaluates to true, this instance of this adapter starts as part of the JVM engine that runs this EventFlow module. If this field is set to No or to a module parameter that evaluates to false, the adapter instance is loaded with the engine, but does not start until you send an sbadmin resume command, or until you start the component with StreamBase Manager.

Enable Error Output Port: Select this check box to add an Error Port to this component. In the EventFlow canvas, the Error Port shows as a red output port, always the last port for the component. See Using Error Ports to learn about Error Ports.

Description: Optionally enter text to briefly describe the component's purpose and function. In the EventFlow canvas, you can see the description by pressing Ctrl while the component's tooltip is displayed.

Operator Properties Tab

Property Type Description
Enable Status On Success check box When enabled the adapter will send out a status message for every successful mesage the is Nacked.
Enable Status Port check box When enabled the adapter will send out informational data on the status port about various states of the adapter.
Log Level drop-down list Controls the level of verbosity the adapter uses to issue informational traces to the console. This setting is independent of the containing application's overall log level. Available values, in increasing order of verbosity, are: OFF, ERROR, WARN, INFO, DEBUG, TRACE, and ALL.

Data Port

Description

Use the data port to supply the required message data to Nack.

Data Port Schema

  • channel, integer. The channel ID on which to send the Nack. This value is output by the consumer adapter.

  • envelope.deliveryTag, tuple<long>. The deliveryTag of the message to Nack. This value is output by the consumer adapter.

  • multiple (optional), boolean. An optional field that determines whether the server should Nack just this message (false) or all previous as well (true). If this value is missing or null false is used.

Status Port

Description

The status port is used to send status information tuples downstream to inform the user of changes.

Status Port Schema

  • type, string. The type of status information emitted on this port. Status types are:

    • Error — Indicates this message is related to an error that occurred.

    • Warn — Indicates this message is related to a warning that the user should be aware of.

    • Info — Indicates this message is related to extra status information.

  • action, string. Always Nack

  • object, string. This value may be null. If not null, it contains a value relevant to the status message.

  • message, string. This is a formatted human readable message that explains the status message.

Concurrency Tab

Use the Concurrency tab to specify parallel regions for this instance of this component, or multiplicity options, or both. The Concurrency tab settings are described in Concurrency Options, and dispatch styles are described in Dispatch Styles.

Caution

Concurrency settings are not suitable for every application, and using these settings requires a thorough analysis of your application. For details, see Execution Order and Concurrency, which includes important guidelines for using the concurrency options.