B and C: ds benchmark unstable for READ and DELETE operation in 3node cluster

1node ds benchmark jobs dont show unstability

https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-1node-periodic-benchmark-all-boron/plot/
https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-1node-periodic-benchmark-all-carbon/plot/
https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-1node-periodic-benchmark-only-boron/plot/
https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-1node-periodic-benchmark-only-carbon/plot/

and all operations (READ,PUT,MERGE,DELETE) preforms stable according to the long term thrends

3node ds benchmark jobs show that PUT and MERGE preform stable, but READ and DELETE dont

https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-3node-periodic-benchmark-all-boron/plot/
https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-3node-periodic-benchmark-all-carbon/plot/
https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-3node-periodic-benchmark-only-boron/plot/
https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-3node-periodic-benchmark-only-carbon/plot/

Having a closer look at e.g.
https://jenkins.opendaylight.org/releng/view/controller/job/controller-csit-3node-periodic-benchmark-only-carbon/plot/getPlot?index=1&width=750&height=1000
shows that ds benchmark with FOL_(running on a follower node) prefix are not that stable