Eventing: Very low throughput for multi source for noop timers

Test

http://showfast.sc.couchbase.com/#/timeline/Linux/eventing/thr/Timer#throughput100M_timer_noop_magma_themis 

We run noop timer tests with 1 source collection and multiple source collection(10 scope , 1 collection/scope, total 10 collections).  

Observed very low throughput 

Test Job : http://perf.jenkins.couchbase.com/job/themis-temp/425/console 

cbmonitor : http://cbmonitor.sc.couchbase.com/reports/html/?snapshot=themis_712-3335_process_timer_events_2827&snapshot=themis_712-3335_process_timer_events_f0fb