What cause this error?

Question

I am running two docker containers one is for hadoop basic services and other is for flume. Services are running successfully. I linked two containers env variables are automatically set by docker successfully.

1.2.3.4    7ab4ffb30dc0
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
127.0.0.1       localhost
::1     localhost ip6-localhost ip6-loopback

fe00::0 ip6-localnet

This is My /etc/hosts file for hadoop. When i run

hadoop fs -ls /
hadoop fs -ls hdfs://127.0.0.1:8020/

Works fine. But if i run

hostname

it returns 7ab4ffb30dc0

So i tried

hadoop fs -ls hdfs://1.2.3.4:8020/

it says Call From 7ab4ffb30dc0/1.2.3.4 to 7ab4ffb30dc0:8020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused

Any suggestions?

Hello, I learned from that site

These are the directions which i learened to tackle serverfault problem

  telnet localhost

says connection refused. it tried to connect to 127.0.0.1 and 0::

  telnet feorar.org

works so telent daemon is running

  telnet localhost 44444

says Trying ::1... Connected to localhost. Escape character is '^]'. Connection closed by foreign host. but

  netstat -tna

says service is listening at :::44444

  telnet localhost 25

works. there is an entry for port 25.

I don't understand what's the difference between :::44444 and ::1:25 under localhost of netstat -tna 's output. Any help?

This question is being voted for closure because the author does not show a level of technical understanding or appropriate due diligence in researching the topic that the community judges as being a minimum barrier to participate. — Wesley, Feb 06 '15 at 07:49

user9517 · Answer 1 · 2015-02-04T17:05:01.487

My suggestion is to read the information provided.

java.net.ConnectException: Connection refused;

This generally means nothing is listening on the specified IP:Port.

Note also this information is provided

http://wiki.apache.org/hadoop/ConnectionRefused

and it's first line

You get a ConnectionRefused Exception when there is a machine at the address specified, but there is no program listening on the specific TCP port the client is using -and there is no firewall in the way silently dropping TCP connection requests.

There is more information in the helpful link too, you should read it.

What cause this error?

1 Answers1

My suggestion is to read the information provided.

Please be bothered to read the information provided before wasting the internet's time.