[HADOOP-5094] Show dead nodes information in dfsadmin -report

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.18.2
• Fix Version/s: 0.21.0
• Hadoop Flags: Incompatible change, Reviewed
• Release Note: Changed df dfsadmin -report to list live and dead nodes, and attempt to resolve the hostname of datanode ip addresses.
• Assignee: Jakob Homan
• Reporter: Jim Huang
• Created: 21/Jan/09 18:30
• Updated: 17/Jul/14 21:27
• Resolved: 04/Feb/09 00:31

Description

As part of operations responsibility to bring back dead nodes, it will be good to have a quick way to obtain a list of dead data nodes.
The current way is to scrape the namenode web UI page and parse that information, but this creates load on the namenode.
In search of a less costly way, I noticed dfsadmin -report only reports data nodes with State: "In Service" and "Decommission in progress" get listed.
Asking for a cheap way to obtain a list of dead nodes.

In addition, can the following requests be reviewed for additional enhancement and changes to dfsadmin -report.

• Consistent formatting output in "Remaining raw bytes:" for the data nodes should have a space between the exact value and the parenthesized value.
  Sample:
  Total raw bytes: 3842232975360 (3.49 TB)
  Remaining raw bytes: 146090593065(136.06 GB)
  Used raw bytes: 3240864964620 (2.95 TB)

• Include the running version of Hadoop.

• What is the meaning of "Total effective bytes"?

• Display the hostname instead of the IP address for the data node (toggle option?)

Issue Links

• duplicates: HDFS-363 list of dead nodes with time information
• incorporates: HDFS-363 list of dead nodes with time information
• is related to: HADOOP-4281 Capacity reported in some of the commands is not consistent with the Web UI reported data