Nishant Bangarwa 0853273091 Add tier based usage metrics for historical nodes to help with autoscaling (#8636)
* Add tier based usage metrics for historical nodes to help with druid historical autoscaling

Add tier based usage metrics for historical nodes to help druid cluster orchestration systems understand the historical node usage and requirements. Following metrics would be helpful -

tier/required/capacity- total capacity in bytes required in each tier. Dimensions - tier
tier/total/capacity - total capacity in bytes available in a given tier. Dimension - tier
tier/historical/count - no. of historical nodes available in each tier. Dimension - tier
tier/replication/factor - configured maximum replication factor in given tier. Dimension - tier

* fix unit test failures
2019-10-08 19:55:32 -07:00
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