[HDFS-11864] Document Metrics to track usage of memory for writes

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.9.0, 2.7.4, 3.0.0-alpha4, 2.8.2
• Component/s: documentation
• Target Version/s: 2.7.4
• Hadoop Flags: Reviewed
• Assignee: Yiqun Lin
• Reporter: Brahma Reddy Battula
• Created: 22/May/17 12:52
• Updated: 24/Apr/18 20:50
• Resolved: 23/May/17 16:07

Description

HDFS-7129 introduced followings metrics which are not documented.

	  // RamDisk metrics on read/write
	  @Metric MutableCounterLong ramDiskBlocksWrite;
	  @Metric MutableCounterLong ramDiskBlocksWriteFallback;
	  @Metric MutableCounterLong ramDiskBytesWrite;
	  @Metric MutableCounterLong ramDiskBlocksReadHits;
	
	  // RamDisk metrics on eviction
	  @Metric MutableCounterLong ramDiskBlocksEvicted;
	  @Metric MutableCounterLong ramDiskBlocksEvictedWithoutRead;
	  @Metric MutableRate        ramDiskBlocksEvictionWindowMs;
	  final MutableQuantiles[]   ramDiskBlocksEvictionWindowMsQuantiles;
	
	
	  // RamDisk metrics on lazy persist
	  @Metric MutableCounterLong ramDiskBlocksLazyPersisted;
	  @Metric MutableCounterLong ramDiskBlocksDeletedBeforeLazyPersisted;
	  @Metric MutableCounterLong ramDiskBytesLazyPersisted;
	  @Metric MutableRate        ramDiskBlocksLazyPersistWindowMs;
	  final MutableQuantiles[]   ramDiskBlocksLazyPersistWindowMsQuantiles;

Issue Links

• is related to: HDFS-7129 Metrics to track usage of memory for writes