[HADOOP-13291] Probing stats in DFSOpsCountStatistics/S3AStorageStatistics should be correctly implemented

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.0
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: fs
• Target Version/s: 2.8.0, 3.0.0-alpha1
• Assignee: Mingliang Liu
• Reporter: Mingliang Liu
• Created: 18/Jun/16 09:00
• Updated: 30/Aug/16 01:13
• Resolved: 20/Jun/16 23:35

Description

To probe a stat in StorageStatistics, users can use the StorageStatistics#isTracked() API. Currently DFSOpsCountStatistics implements this function wrongly. S3AStorageStatistics borrowed the same idea and also has the same error.

1. The isTracked() is not correctly implemented. I believe this was an omission in code.
2. isTracked() checks a stat with operation symbol (instead of enum name). getLongStatistics() should return LongStatistics iterators with symbol as name, instead of the enum variable name. Or else, isTracked(getLongStatistics().next().getName()); returns false. This will lead to confusion.