This documentation page describes a feature of version 3.3 of Iguana. In Iguana 4.0 and later, any channel can contain a message filter, and any channel can be used as the source for another channel. See Configuring the Filter for details on using a message filter in Iguana 4.0 and later, and see From Channel for details on using a previously defined channel as a source component for another channel definition.

Iguana's Message Filter functionality allows you to create a persistent, transactional queuing system that is capable of accomplishing the following:

• Guaranteeing message delivery;
• Being fault tolerant, meaning that the queue can be interrupted at any time without losing messages (as long as an ACK is received); and
• Performing useful store-and-forward functions.

The routing features that are available from the To/From Message Filter components provide the following benefits:

• One inbound data source that can direct HL7 messages to a "To Message Filter" Iguana channel, which provides store-and-forward HL7 message handling;
• The means to split the inbound channel into one or more outbound data streams;
• Each outbound data stream can be uniquely configured with all the Iguana outbound methods;
• A copy of the original inbound data stream can be filtered and forwarded "as is" to a target destination using a message's filter criteria;
• A copy can be filtered, parsed and used to populate local and remote databases;
• A copy can be filtered, parsed and modified in fine detail with scripted transformation - this allows message to be reformatted, HL7 segments to be removed or added, data to be scrubbed out, etc.; and
• One-to-many routing paths.

A queue or message filter configuration becomes particularly useful when systems are down for extended periods in the event of unforeseen circumstances (e.g. power loss). The store-and-forward capability in Iguana allows you to export the messages that are "queued" in the message filter and manually resubmit them to your target destination(s) using the HL7 Simulator utility. This type of queuing configuration allows you to recover from downtime quickly.

This section shows you how to set up a queuing configuration using two channels. In this section, you will learn how to:

• Create the two channels required to set up the queuing configuration;
• Send sample data from the HL7 Simulator to the Message Filter to the Database; and
• View stored messages that are queued in the Message Filter and change their status using the Routing tab.