Flink sent/received bytes related metrics: how are they calculated?

Posted by Andrea Spina on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Flink-sent-received-bytes-related-metrics-how-are-they-calculated-tp28244.html

Dear Community, I'd like to ask for some details about bytes related metrics in Flink. Precisely, I'm looking at bytes sent and bytes received metrics: what I am recording is the following:

I am reading from a Kafka topic A records with schema K using a source Sin belonging to a pipeline P1. The topic A is filled with K data using a separated pipeline p2 and a sink Sout.

Basically what I register is that the bytes sent metric of Sin - available through the Flink UI -measure twice or more respect of the bytes received of Sout. For instance, if my sink Sout records 10GB of bytes received inbound, then my source Sin emits between 20-25GB bytes sent.

Is someone able to detail how these two metrics are calculated? 

Thank you,

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