Hello,

At the moment I am developing a storm topology for processing raw machine
measurement data. However, I am running into unexplainable problems with
the spout.

I am running a simple storm topology on Azure HDInsight, written in Java.
Events are read out of an eventhub, for which I am using the microsoft
eventhub spout (version 0.9). This eventhub has 8 partitions, which means
that I also need 8 instances of the Eventhubspout.

However, when I am running the topology for a couple of hours, the spouts
stop receiving messages one after another, until each spout is quiet. No
feedback is given whatsoever. The eventhub is still up and running when I
inspect it through other means. Storm/the spouts are simply not registering
anything anymore.

I have several ideas about what might be the problem here:


   - First, recently we have adjusted the messages that are being sent to
   the topology. Through batching (and parsing in the topology itself), we
   decreased the amount of messages significantly. The size of each message
   has grown enormously as well. This can cause two problems:


   1. Each partition only gets a message every +/- 4 seconds, which is
   ridiculously low for storm. Could it be that it automatically times-out and
   crashes because of this?
   2. Could the message 'sometimes' be too big, causing the spout to crash
   / show weird behavior?


   - Second, from time to time it can happen that the eventhub is briefly
   offline, because of some Azure error or unavailability of the network. That
   could mean that the eventhub is not sending messages for a while. While not
   receiving data, the spout shuts down but cannot wake up anymore?


For each of these mentioned reasons, shouldn't the eventhub spout
automatically recover from this? What can be done to debug / tackle this
problem?

Thank you very much for your time in advance!

Kind regards,



Christian

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