Channels - AMQP

Overview

Used to create, update, delete and browse through AMQP channels.

Each channel represents a connection through which AMQP broker messages are received by Zato. A given service is invoked for each message received.

Creating or updating a channel (re-)establishes a connection to an AMQP broker and there are as many connectors and connections to any broker as there are active channels and outgoing connections using it.

For instance, if there is 1 AMQP definition and 5 channels using it, there will be 5 connector processes started in a cluster each maintaining 1 connection to the broker pointed to by the definition.

Reading messages off a queue and invoking a service is an asynchronous activity - messages are not rolled back onto queues if there are any errors along.

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Create and Edit

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Header Notes
Name Channel name
Active Documented below
Definition AMQP definition to read basic connection information from
Queue Name of the AMQP queue to fetch messages from
Consumer tag prefix Each channel can be given a prefix that can be used to tell channels apart from AMQP’s end, e.g. each Zato environment can use a different one
Service Name of an already existing service to invoke for each AMQP message received
Data format (Optional) The expected data format Zato should parse incoming messages as. This will also populate a service’s data_format attribute.

Delete

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Stops a channel’s connector and deletes the channel from ODB.

The ‘Active’ flag

If a channel is made inactive, its underlying AMQP connection will be stopped but the connector itself will be still running.