[HDFS-12320] Add quantiles for transactions batched in Journal sync

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.1.0
• Component/s: metrics, namenode
• Hadoop Flags: Reviewed
• Assignee: Hanisha Koneru
• Reporter: Hanisha Koneru
• Created: 18/Aug/17 19:03
• Updated: 25/Sep/17 19:10
• Resolved: 23/Sep/17 17:37

Description

We currently track the overall count of the transactions which were batch during journal sync through the metric TransactionsBatchedInSync. It will be useful to to have a quantile to measure the transactions batched together over a period. This would give a better understanding of the distribution of the batching.