Instrument scrape pool `sync()`
Instrument scrape pool `sync()`

Instruments:
- duration
- count

msiebuhr/prometheus,Stackdriver/stackdriver-prometheus,alileza/prometheus,brancz/prometheus,Gouthamve/prometheus,msiebuhr/prometheus,dsymonds/prometheus,dsymonds/prometheus,JavierZunzunegui/prometheus,amorken/prometheus,tattsun/prometheus,gottwald/prometheus,keegancsmith/prometheus,PrFalken/prometheus,keegancsmith/prometheus,eliothedeman/prometheus,AlekSi/prometheus,ton31337/prometheus,Stackdriver/stackdriver-prometheus,Colstuwjx/prometheus,gottwald/prometheus,Colstuwjx/prometheus,dmilstein/prometheus,brancz/prometheus,sudhi-vm/prometheus,dmilstein/prometheus,datajet-io/prometheus,kzittritsch/prometheus,agaoglu/prometheus,alileza/prometheus,kangwoo/prometheus,kangwoo/prometheus,ton31337/prometheus,GoogleCloudPlatform/prometheus,datajet-io/prometheus,sudhi-vm/prometheus,slok/prometheus,brancz/prometheus,tomwilkie/prometheus,prometheus/prometheus,alileza/prometheus,gottwald/prometheus,Colstuwjx/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,tattsun/prometheus,Conorbro/prometheus,gottwald/prometheus,adamron1/prometheus,yanghongkjxy/prometheus,AlekSi/prometheus,sudhi-vm/prometheus,Conorbro/prometheus,kangwoo/prometheus,Colstuwjx/prometheus,agaoglu/prometheus,eliothedeman/prometheus,tomwilkie/prometheus,amorken/prometheus,tattsun/prometheus,msiebuhr/prometheus,alileza/prometheus,kzittritsch/prometheus,eliothedeman/prometheus,PrFalken/prometheus,datajet-io/prometheus,Gouthamve/prometheus,amorken/prometheus,PrFalken/prometheus,slok/prometheus,msiebuhr/prometheus,dsymonds/prometheus,amorken/prometheus,adamron1/prometheus,dmilstein/prometheus,eliothedeman/prometheus,tomwilkie/prometheus,adamron1/prometheus,GoogleCloudPlatform/prometheus,sudhi-vm/prometheus,JavierZunzunegui/prometheus,Gouthamve/prometheus,Stackdriver/stackdriver-prometheus,kzittritsch/prometheus,Conorbro/prometheus,ton31337/prometheus,agaoglu/prometheus,alileza/prometheus,yanghongkjxy/prometheus,yanghongkjxy/prometheus,brancz/prometheus,agaoglu/prometheus,prometheus/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,datajet-io/prometheus,kangwoo/prometheus,keegancsmith/prometheus,slok/prometheus,SaltedMan/prometheus-annotated,AlekSi/prometheus,slok/prometheus,yanghongkjxy/prometheus,GoogleCloudPlatform/prometheus,dsymonds/prometheus,JavierZunzunegui/prometheus,SaltedMan/prometheus-annotated,GoogleCloudPlatform/prometheus,prometheus/prometheus,PrFalken/prometheus,prometheus/prometheus,tomwilkie/prometheus,keegancsmith/prometheus,dmilstein/prometheus,SaltedMan/prometheus-annotated,Conorbro/prometheus,tattsun/prometheus,JavierZunzunegui/prometheus,adamron1/prometheus,ton31337/prometheus,AlekSi/prometheus,SaltedMan/prometheus-annotated,kzittritsch/prometheus,Stackdriver/stackdriver-prometheus