make alexandra replica updates a bit smarter

6 jobs for main in 14 minutes and 43 seconds (queued for 7 seconds)
Status Name Job ID Coverage
  Analysis
passed golint #106171

00:03:22

 
  Test
passed code_coverage #106174

00:08:32

66.0%
passed code_coverage_report #106175

00:08:19

66.0%
passed race_detector #106173

00:09:12

passed unit_tests #106172

00:03:50

 
  Build
passed build #106176

00:02:07