[AMBARI-18185] Selecting one host when topN is set, throws an error

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.4.0
• Fix Version/s: 2.5.0
• Component/s: ambari-metrics
• Assignee: Aravindan Vijayan
• Reporter: Aravindan Vijayan
• Created: 17/Aug/16 17:14
• Updated: 15/Sep/16 03:50
• Resolved: 14/Sep/16 22:16

Description

topN is available by default on almost all Grafana templatized dashboards.
When viewing any of these dashboards, if only one "host" or templated option is chosen, then AMS returns with an exception (screenshot attached).
Sample query:
collectorhost:6188/ws/v1/timeline/metrics?metricNames=cpu_system._avg&hostname=hostname&appId=HOST&startTime=1470925360&endTime=1470946960&topN=20&topNFunction=avg&isBottomN=false