GC improvement: Reduce string objects from Publisher and Consumer stats#1480
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sijie
approved these changes
Apr 4, 2018
jai1
approved these changes
Apr 4, 2018
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Motivation
We have seen large young GC-pause in broker in specific states. Below is one of the example where broker's young gc reached to 1 sec and after capturing heap-dump it shows large number of string and char[] objects allocated by the producer/consumer stats of the topic and .
Young GC > 1.2 sec
Highest object allocation classes: String, char[]
Modifications
Producer/Consumer stats stores 4 String objects (address, producerName, connectedSince, version) which don't get modified once they are set. So, reducing 4 strings and char[] to 1 and store offsets of stats-placeholder which will reduce number of string and char[] objects.
Result
It will help to reduce GC when broker is serving many topics.
I am going to make some more GC enhancement in separate PR.