tree fc4774b1696b4904f2043d2f364bc91971fb98a0
parent e90ffbee09919aa6cfadc999cc82843b331e2445
author Julia Wang <juliaw@apache.org> 1501036182 -0700
committer Sergiy Matusevych <motus@apache.org> 1509563215 -0700

[REEF-1733] Define Driver Metrics and observer

   * Add interface for DriverMetrics and impl
   * Add DriverMetricsObservers and configuration module
   * Let MetricsService implement IDriverMetrics observer
   * Update test driver and test case

JIRA: [REEF-1733](https://issues.apache.org/jira/browse/REEF-1733)

This closes #1342