aggregator w/ correlation-strategy-expression only working once

[asanderson]

My use case is that I would like to aggregate a batch of messages w/ no correlation strategy before sending it to another channel. Unfortunately, a correlation strategy is required, so I tried the following workaround but it only works for the first batch:

<int:aggregator id = "myAggregator"
input-channel = "inputChannel"
output-channel = "outputChannel"
send-partial-result-on-expiry = "true"
send-timeout = "1000"
correlation-strategy-expression = "1"
release-strategy-expression = "size() gt 20"
/>

Any idea why this only works once?

Thanks in advance,

Steve

[oleg.zhurakousky]

Look at this sample: https://github.com/olegz/s12gx.2011/...ion/aggregator
It talks about exactly the same issue. You can also see the youtube version which touches in this and other use cases http://www.youtube.com/watch?v=RY6dN...5&feature=plcp
Basically you need to set "expire-groups-upon-completion" attribute to false

expire-groups-upon-completion="false"

[asanderson]

Oleg,

Thanks for the quick reply.

I didn't see that attribute in the reference manual; however, it looks like it's false by default. I tried setting it explicitly to false but I still have the same problem.

I failed to mention it, but I'm using spring-integration-2.2.0.M2.

Steve

[oleg.zhurakousky]

If you go through that demo you'll see that you ned to set it to true. Just go through the read me and/or the screencast

[asanderson]

Oleg,

Sorry, I guess I misunderstood the attribute.

Setting expire-groups-upon-completion="true" worked!

Thanks for your help.

Steve

[Cleric]

Hello

Let me explain it shortly too:
Result of CorrelationStrategy is presented as MessageGroupId. So, your ReleaseStrategy marks that group as compleat and doesn't aggregate it again in the default case - expire-groups-upon-completion="false"

Cheers,
Artem Bilan

[asanderson]

Artem,

Thanks for the explanation. It was very helpful.

Hopefully, it will be documented as well in the reference manual soon. ;-)

Steve