CPU/memory usage on otherwise idle system

As I add more and more empty buckets to an idle Couchbase system built from just one (1) node with an 8 CPU VM and 24MB of RAM doing nothing the CPU continues to climb for both memcached and beam.smp at 28 buckets (26 empty) we use almost 1/2 of the cores in the 8 CPU VM

I start with no buckets and the top output is relatively low (top -n 4 user linuxbrew)

{{PID     USER PR NI  VIRT     RES SHR   S %CPU %MEM   TIME+ COMMAND
2401 linuxbr+ 20 0 4182012 180416  7128 S  8.0  0.7 0:16.65 beam.smp
2741 linuxbr+ 20 0 8917820 484636 21860 S  2.0  2.0 0:18.64 java
2541 linuxbr+ 20 0  743128  32984 19756 S  0.8  0.1 0:01.46 indexer
2594 linuxbr+ 20 0  916168  54980 39020 S  0.8  0.2 0:00.93 cbq-engine}}

I add 4 buckets 2 with data (32K items and 5K items) (top -n 4 user linuxbrew)

{{PID     USER PR NI   VIRT    RES   SHR S %CPU %MEM   TIME+ COMMAND
2401 linuxbr+ 20 0 4704780 599744  7192 S  61.3 2.4 6:34.93 beam.smp
2669 linuxbr+ 20 0 2465196 194636 24328 S  51.0 0.8 2:56.27 memcached
2541 linuxbr+ 20 0 1389776 335672 21896 S  16.4 1.4 2:31.17 indexer
2553 linuxbr+ 20 0  851196 307380 15856 S   2.4 1.2 0:34.77 projector}}

(more details in attachment)

I add 24 more empty buckets (28 total) (top -n 4 user linuxbrew)

{{PID     USER PR NI   VIRT    RES   SHR S %CPU %MEM    TIME+ COMMAND
2669 linuxbr+ 20 0 3341740 906616 24328 S 191.8 3.7 30:40.84 memcached
2401 linuxbr+ 20 0 7157152 1.784g  7192 S 144.7 7.6 36:47.43 beam.smp
2541 linuxbr+ 20 0 1389968 325808 21896 S  12.8 1.3  6:08.28 indexer
2459 linuxbr+ 20 0 4222184 315872 16748 S   2.3 1.3  0:48.81 beam.smp}}

Is this really the expected CPU usage behavior for a one (1) node system doing 
nothing  e.g. the final CPU for the Couchbase user "linuxbrew" CPU sums to 351.6% 
this is about 3.5 cores or almost 1/2 of my available compute.

I have attached an lsof output of running 28 bucket system and in addition some strace outputs.