Netconf performance in cluster is way worse than in single node

Single node CSIT result [0] is around 400 requests per second.
Three node test (device configured through node 1, device data accessed through node 3) result [1] is almost 20 times worse.

[0] https://logs.opendaylight.org/releng/jenkins092/netconf-csit-1node-periodic-scale-all-carbon/219/archives/log.html.gz#s1-s2-t5-k3-k15-k6-k2-k2
[1] https://logs.opendaylight.org/sandbox/jenkins091/netconf-csit-3node-periodic-clustering-scale-all-carbon/1/archives/log.html.gz#s1-s2-t6-k3-k15-k6-k2-k2