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From rohit bhatia <>
Subject Memory Usage of a connection
Date Fri, 31 Aug 2012 05:33:17 GMT
I was wondering how much would be the memory usage of an established
connection in cassandra's heap space.

We are noticing extremely frequent young generation garbage collections
(3.2gb young generation, ParNew gc every 2 seconds) at a traffic of
20,000qps for 8 nodes.
We do connection pooling but with 1 connection for 6 requests with phpcassa.
So, essentially every node has on an average 500 connections
created/destroyed every second.
Could these 500 connections/second cause (on average) 2600Mb memory usage
per 2 second ~ 1300Mb/second.
or For 1 connection around 2-3Mb.

Is this value expected? (our write requests are simple counter increments
and cannot take up 500KB per request as calculation suggests, rather should
take up only a few hundred bytes).


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