Cassandra box is getting heavy load with kong

Hi all,
We are seeing some strange behaviour with kong and cassandra , The issue is with 5 sec DB update frequency and 2 nginx worker process on a 4 GB box for kong , The connected 3 node cassandra box is getting heavy load when we try to edit the api configs, the cassandra box is going unavailable since the load is heavy and kong is trying to reconnect the cassandra instance. We are also

INFO [SharedPool-Worker-1] 2017-12-15 18:59:58,631 - Unexpected exception during request; channel = [id: 0xafcad115, / :laughing: /] Error while read(…): Connection reset by peer
at Method) ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at$EpollSocketUnsafe.doReadBytes( ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at$EpollSocketUnsafe.epollInReady( ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$ ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at io.netty.util.concurrent.DefaultThreadFactory$ ~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at [na:1.8.0_151]

errors at the cassandra side The kong stats are looking fine with 25% CPU usage and 20% memory consumptions we are trying to operate on a 15 node kong setup with 600k RPM,

Is there anyone seeing issues similar to this? if so someone find out a solution?