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Check Status of Running Nodes in Hadoop

To see if nodes in your Hadoop cluster connected and run, followings are the ways to see

JPS Command

Run jps command in master node and slave nodes. In master node, the output of the jps should be something like this
$ jps
1634 JobHistoryServer
692 NameNode
2471 Jps
1191 ResourceManager
841 DataNode
1023 SecondaryNameNode
1311 NodeManager
When you run jps in slave, the output should be something like this
$ jps
528 Jps
292 NodeManager
170 DataNode

hdfs dfsadmin -report

This is a very nice tool to see the statistic of each nodes in your Hadoop cluster. When you run the command, you will get ouput something like
$ hdfs dfsadmin -report
Configured Capacity: 82999410688 (77.30 GB)
Present Capacity: 59326111744 (55.25 GB)
DFS Remaining: 59325284352 (55.25 GB)
DFS Used: 827392 (808 KB)
DFS Used%: 0.00%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0
Missing blocks (with replication factor 1): 0
Pending deletion blocks: 0

-------------------------------------------------
Live datanodes (4):

Name: 10.0.0.251:50010 (localhost)
Hostname: localhost
Decommission Status : Normal
Configured Capacity: 20749852672 (19.32 GB)
DFS Used: 376832 (368 KB)
Non DFS Used: 5901377536 (5.50 GB)
DFS Remaining: 14831321088 (13.81 GB)
DFS Used%: 0.00%
DFS Remaining%: 71.48%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Apr 26 16:24:27 UTC 2018
Last Block Report: Thu Apr 26 16:06:36 UTC 2018


Name: 10.0.0.252:50010 (d2)
Hostname: d2
Decommission Status : Normal
Configured Capacity: 20749852672 (19.32 GB)
DFS Used: 368640 (360 KB)
Non DFS Used: 5901385728 (5.50 GB)
DFS Remaining: 14831321088 (13.81 GB)
DFS Used%: 0.00%
DFS Remaining%: 71.48%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Apr 26 16:24:27 UTC 2018
Last Block Report: Thu Apr 26 16:06:36 UTC 2018


Name: 10.0.0.253:50010 (d3)
Hostname: d3
Decommission Status : Normal
Configured Capacity: 20749852672 (19.32 GB)
DFS Used: 36864 (36 KB)
Non DFS Used: 5901717504 (5.50 GB)
DFS Remaining: 14831321088 (13.81 GB)
DFS Used%: 0.00%
DFS Remaining%: 71.48%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Apr 26 16:24:27 UTC 2018
Last Block Report: Thu Apr 26 16:06:36 UTC 2018


Name: 10.0.0.254:50010 (d4)
Hostname: d4
Decommission Status : Normal
Configured Capacity: 20749852672 (19.32 GB)
DFS Used: 45056 (44 KB)
Non DFS Used: 5901709312 (5.50 GB)
DFS Remaining: 14831321088 (13.81 GB)
DFS Used%: 0.00%
DFS Remaining%: 71.48%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Apr 26 16:24:27 UTC 2018
Last Block Report: Thu Apr 26 16:06:36 UTC 2018

Use web interface

If you like to work in black screen like me, this will be the last option for you. However, some of the people love this way... :D
To open the web interface, by default, it is in http://:8088
So, for example your server is 192.168.10.192, you can open the web interface using
http://192.168.10.192:8088

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