SequenceSizeComparator

[ttruong]

Since an aggregator may get messages from different channels it would be great to have a comparator for sorting the incoming messages.

Cheers Tai

[ttruong]

Of course I mean a SequenceNumberComparator

[Mark Fisher]

There is a <resequencer/> as well, and its role is very similar to Aggregator except that it does not combine the incoming Messages into a single Message. It does, however, re-order the Messages according to the sequenceNumber value. Have you tried using that?

[ttruong]

Great! I will try that.

Thanks Tai

[ttruong]

And how do I configure the resequencer? It seems I cannot add that to an aggregator.

I tried this:
<resequencer input-channel="requestChannel"/>

But that seems not to work.

[mbogoevici]

Tai,

The <resequencer/> does not get added to an <aggregator/>, you would have to use it instead of the <aggregator/> (with the same input/output channels that you intended to use there).

Regards,
Marius

[iwein]

Tai,
The <resequencer/> does not get added to an <aggregator/>, you would have to use it instead of the <aggregator/> (with the same input/output channels that you intended to use there).

To be a bit more precise you would use a resequencer AND an aggregator as two separate endpoints. The resequencer passes messages in sequence, where the aggregator combines multiple messages into one.

[ttruong]

Ok. Let me be more precise. I already thought that I have to use a resequencer first and then an aggregator. Like this:

	<resequencer id="csvResequencer" input-channel="rowChannel" output-channel="resequencerChannel"/>

	<aggregator id="csvToAdaptersTranslatorServiceActivator" input-channel="resequencerChannel" output-channel="adapterChannel"
		ref="csvToAdaptersTranslator" method="translate">
	</aggregator>

But as I can already see in eclipse it is complaining that: "Attribute 'input-channel' is not allowed to appear in element resequencer".

Trying to read the configuration of course I get the following:

Caused by: org.xml.sax.SAXParseException: cvc-complex-type.3.2.2: Attribute 'input-channel' is not allowed to appear in element 'resequencer'.
at org.apache.xerces.util.ErrorHandlerWrapper.createS AXParseException(Unknown Source)
at org.apache.xerces.util.ErrorHandlerWrapper.error(U nknown Source)

[Mark Fisher]

This issue has been resolved on the SVN head. I added an issue so that others who encounter this will be able to find it in JIRA: http://jira.springframework.org/browse/INT-406

If you are unable to upgrade to the head version, know that we are aiming for RC1 at the end of next week. I believe in the meantime you can add a resequencer element's id as a "ref" value within a <service-activator/>. That is admittedly clunky, but here's what the (more consistent) head version of "resequencerParserTests.xml" looks like:

  <resequencer id="completelyDefinedResequencer" 
		input-channel="inputChannel2"
		output-channel="outputChannel" 
		discard-channel="discardChannel"
		send-timeout="86420000" 
		send-partial-result-on-timeout="true"
		reaper-interval="135" 
		tracked-correlation-id-capacity="99"
		timeout="42" 
		release-partial-sequences="false"/>