Magma rebalance-swap time increased from 1079 mins to 1276 mins on build 7.0.0-3016

Test: Rebalance-swap (min), 4 -> 4, 10B x 1KB, 15K ops/sec (90/10 R/W), 10% cache miss rate, Magma

Build: 7.0.0-2741

Rebalance time: 1079

Job: http://perf.jenkins.couchbase.com/job/rhea-5node1/157/ 

Logs:

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-157/172.23.97.21.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-157/172.23.97.22.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-157/172.23.97.23.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-157/172.23.97.24.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-157/172.23.97.25.zip

Build: 7.0.0-3016

Rebalance time: 1276

Job: http://perf.jenkins.couchbase.com/job/rhea-5node1/297/ 

Logs: 

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-297/172.23.97.21.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-297/172.23.97.22.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-297/172.23.97.23.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-297/172.23.97.24.zip

https://s3-us-west-2.amazonaws.com/perf-artifacts/jenkins-rhea-5node1-297/172.23.97.25.zip