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nifi detect duplicate MapCacheServer Error

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New Contributor

I have configured a DistributedMapCacheClientService and a DistributedMapCacheServer which are used by the DetectDuplicate processor. But when I try to process flowfiles using the DetectDuplicate Processor I receive an error: "Detect Duplicate failed to process session due to java.nio.channels.UnresolvedAdressException". So is there any additional configuration needed? Btw, I have installed Nifi additionally on my Hortonworks Sandbox, which is running locally.

1 ACCEPTED SOLUTION

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Since you are running on a standalone NiFi instance, the MapCacheServer is running locally, then you should put 'localhost' for the property 'Server Hostname' in the client service. Let me know if it helps.

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6 REPLIES 6

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Hi @Alexander Flick,

Could you share the configuration of your controller services? Are the two controller services running?

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New Contributor

MapCacheServer:

6226-ybbu7.png

MapCacheClientService:

6227-xw2e8.png

Both Controller Services are enabled but how can I check that they are running?

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Since you are running on a standalone NiFi instance, the MapCacheServer is running locally, then you should put 'localhost' for the property 'Server Hostname' in the client service. Let me know if it helps.

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New Contributor

Yes, that helped - it works 🙂 Thank you so much!

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Expert Contributor

@Pierre Villard

In the cluster mode, if we run MapCacheServer on only NCM, does that mean once NCM fails, the MapCacheServer becomes unavailable?

Is there anyway to avoid it?

Thanks.

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@Alvin Ji,

This is correct with NiFi 0.x. Unless you implement your own MapCacheServer service and separate it from NiFi, I am not sure there is a solution.

With NiFi 1.x (first version to be released in coming days, RC vote in progress), this is solved with a zero-master clustering paradigm.