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5

I can't connect to Hadoop port 9000

rated 0 times [ 5] [ 0] / answers: 1 / hits: 36535 / 1 Year ago, tue, march 21, 2023, 11:12:57

So telnet actually is working, I mean telnet localhost 25 is connecting; but telnet localhost or telnet localhost 9000 got such result:

Trying 127.0.0.1... 

telnet: Unable to connect to remote host: Connection refused

nmap results:

$ nmap localhost



Starting Nmap 6.00 ( http://nmap.org ) at 2013-10-03 00:54 MSK

Nmap scan report for localhost (127.0.0.1)

Host is up (0.00030s latency).

rDNS record for 127.0.0.1: localhost.localdomain

Not shown: 992 closed ports

PORT     STATE SERVICE

22/tcp   open  ssh

25/tcp   open  smtp

80/tcp   open  http

587/tcp  open  submission

631/tcp  open  ipp

3306/tcp open  mysql

5432/tcp open  postgresql

6566/tcp open  sane-port

nmap on 9000 port:

$ nmap -p 9000 localhost



Starting Nmap 6.00 ( http://nmap.org ) at 2013-10-03 00:55 MSK

Nmap scan report for localhost (127.0.0.1)

Host is up (0.000040s latency).

rDNS record for 127.0.0.1: localhost.localdomain

PORT     STATE  SERVICE

9000/tcp closed cslistener

So the question is how to open necessary port, Im using Ubuntu 13.04;
tried to disable ufw, tried to play with iptables; nothing helped. Dunno even what to do...

I need 9000 port for hadoop; I cant access fs without opened 9000 port

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ciousuntru

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3 Years ago

answered 1 Year ago ugeeport · Accepted Answer

The reason for connection refused is simple - the port 9000 is NOT being used (not open).

Use the command => lsof -i :9000 to see what app is using the port. If the result is empty (return value 1) then it is not open.

You can even test further with netcat.

List on port 9000 in terminal session 1

nc -l -p 9000

In another session, connect to it

$ lsof -i :9000

COMMAND   PID  USER   FD   TYPE  DEVICE SIZE/OFF NODE NAME

nc      12679 terry    3u  IPv4 7518676      0t0  TCP *:9000 (LISTEN)

$ nc -vz localhost 9000

Connection to localhost 9000 port [tcp/*] succeeded!

So you need to fix your hadoop settings and make sure all necessary daemons/services are started properly before you can connect to use HDFS.

NOTE: This is NOT telnet nor iptables issue, it's basically TCP/IP basics. Please change the question to sth like "connecting to port 9000 issue".

Update

i need 9000 port for hadoop; I can't access fs without opened 9000 port so base on the context my understanding is that HDFS's namenode is supposed to use port 9000. So check your Hadoop/HDFS configuration files and get the services started.

iptables is irrelevant at this stage because the port is NOT used at all.

You can run iptables -L -vn to make sure there is no rules in effected. You can flush the filter table INPUT chain to make sure sudo iptables -P INPUT ACCEPT && sudo iptables -F -t filter