[PHOENIX-5436] Histogram view of Global Client Metrics

• Type: Improvement
• Status: Patch Available
• Priority: Minor
• Resolution: Unresolved
• Labels: histogram metric-collector metrics
• Assignee: Unassigned
• Reporter: abhishek sen
• Created: 09/Aug/19 02:02
• Updated: 02/Oct/20 23:38

Description

Currently the GlobalClientMetrics enum-class defines Phoenix Global Client Metrics as an enum and each metric-enum tracks a Phoenix Metric object implemented by AtomicMetric class. This tracks a single counter, but in some use cases we want the distribution of a particular metric value over some period of time. One example could be the metric TASK_EXECUTION_TIME. The Global Client metric tracks the aggregate value for the execution time of the task. More useful information to monitor would be the distribution of task execution time instead.
Now, in order to incorporate histogram view of the metric, we can use the Histogram Implementation from hbase-metrics-api package. The current GlobalClientMetric also ultimately adapts to hbase-metrics-api interface but it implements the Gauge class which can only keep track of a single value not a histogram. So one way could be to create a new GlobalClientHistogramMetrics enum class which keeps track of a Histogram (based on MutableTimeHistogram) for each enum-metric instead of a single counter as it is now. The updating of the these new metric can go here within JobManager class where the currently available Global as well as request-level metrics are being updated.