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Storm UI Values

why the value of Emitted, transferred and Acked varies in the Storm UI under "Topology Stats" section and How they are getting calculated. Even if the Number of failure is Zero.

In my Case, Number of Emitted and transferred are same which is correct but the Acked is higher and also Number of failure is Zero(Which is correct). I am using Storm 0.9.3 version.

Thanks in Advance.

Solution

  • Topology stats show all stats for spouts and bolts (the sum of all the emits, transferred, executed ...) at the four varies time interval.

    In order to get the exact value according to the application. You just need to add/change the value of topology.stats.sample.rate: to 1.0 from 0.05 in storm.yaml.

    what i understood is that, Storm samples incoming tuples for computing stats. By default, 5% of them are actually used for computation. When you change it to 1.0 it use 100% of the incoming tuples for computation.