how to debug spark GUI if its not working - apache-spark

My SPARK GUI is not working though I can see my 4040 port is listening whenever I start any spark-submit job.
netstat -an | grep 4040
tcp6 0 0 127.0.0.1:4040 :::* LISTEN
when I give address of my spark master server in my browser , it gives "This site can’t be reached".
I am not sure why it is not responding despite of listening on designated port. I also tried to see in /var/log/spark/ but non of log files gets updated after hitting web URL.
any pointer/suggestion will be highly appreciated.

finally I found an answer. I changed configuration in /etc/hosts
from
127.0.0.1 localhost
to
my machine ip localhost
Now I can see my Spark GUI. Though it is still not giving relevant data but thats another problem to solve now.

Related

This site can’t be reached localhost refused to connect. deployed using jboss 7.1

I deployed my project using jboss7.1 and also it deployed successfully
but I can't access though browser it says This site can’t be reached localhost refused to connect. how to solve this issue?
As this answer mentions,
1 Log in into server via ssh and do next actions from terminal on this server.
2. Run netstat on the port
3.Check state of 1099 port is LISTEN. Remember program name and pid ( last column output of netstat, should be something like 5812/java)
4. Try investigate, what program used it. Run ps aux | grep xxxx where xxxx - pid from step 3

Azure Ubuntu VM application only able to connect on port 80

I have an Ubuntu16.04 VM on Azure, and am trying to run a node server on it. When I bind the port to 80, I am able to access it from my browser (http://a.b.c.d:80). However, if I try to instead bind the server to a different port, such as 3300 or 8080, the browser times out when trying to connect to it. (http://a.b.c.d:3300)
I have ensured that:
There exists an inbound security rule for port 3300 in the NSG
The windows firewall of the machine of the browser allows port 3300 (I have even tried temporarily turning it completely off but to no avail)
I am not using an azure load balancer
I am starting node with root privileges
Node is bound to (port, "0.0.0.0")
I am listening on the correct port (I think?)
netstat -ant | grep 3300 gives
tcp6 0 0 :::3300 :::* LISTEN
I have spent a few hours now researching on the internet how to get it to work and tried everything I could find, but to no avail. If anyone has any input i'd be happy to try it out.
Jason was correct, it was a ufw issue. If anyone comes across this question in the future, I solved it with the command
sudo ufw allow proto tcp from any to any port 3300

Unable to access node server running on specific port from other machine

I am running node server running react application.server is run by webpack. Server is running on 10.121.45.23:3005. I tried opening the application on other machine but page displays connection timed out. I have tried following things to resolve the issue, but nothing helped.
ping 10.121.45.23 from another machine. It is successful.
On server, netstat -ano. I am able to see 10.121.45.23:3005 listening. No loopback address was there as mentioned in many answers on Stack Overflow.
On another machine,telnet 10.121.45.23 3005. It fails and say cannot connect on port 3005. Telnet to some other port on which java is running, is successful. It fails only for node.js server.
So my problems are:
telnet is not working to that port.
Not able to open application on other machine's browser.
Am I missing any checks?
Sounds like you've tested quiet a bit. Have you tried another port, just in case there's a firewall or something?
Also, try explicitly telling webpack to listen on the all-hosts address 0.0.0.0
webpack-dev-server --port 9000 --host 0.0.0.0

Cassandra 3.3 - Remote connection via cqlsh

I am facing some issues trying to connect to Cassandra 3.3.0 on Centos 7 remotely from another machine in the network. It is returning a "timed out" error while trying to connect via
$ cqlsh 192.168.1.56 9042
Same with:
$ cqlsh 192.168.1.56
In my point of view, I have configured the cassandra.yaml file correctly as it worked fine when I tried to connect to a locally running VM (Ubuntu) with an active Cassandra instance.
When I am checking the IPs and ports which have been bound via netstat -lnt, it is returning
tcp6 0 0 192.168.1.56:9042 :::* Listen
Actually the only one which is bound to tcp6. 192.168.1.56:9160 is bound to tcp.
Running on Ubuntu, it returns the same binding to tcp. So the fault is related to that point, I guess.
Some background facts:
I am running Cassandra as root. Both server and clients are running cqlsh 5.0.1, CQL spec 3.4.0 and Cassandra 3.3.0. Python 2.7.5.
The VM is accessible via 192.168.1.56 without problems. Firewall is deactivated and I even have tried to de- and reactivate IPv6. I have tried different combinations configuring the cassandra.yaml -- such as taking the interface instead of its IP directly, but without changes in the result.
All my research has not shown success so far. Has anybody an idea?!
Problem has been solved due to network misconfiguration.
I've changed the below configuration in /etc/ssh/sshd_config
Port 22
AddressFamily inet
ListenAddress 0.0.0.0
ListenAddress ::
I've changed AddressFamily from "any" to "inet".

The controller is not available at localhost JBOSS.7.1.1.FINAL

When i run the jboss-cli.sh,
I get this message.
[root bin]# sh jboss-cli.sh
You are disconnected at the moment. Type 'connect' to connect to the server or 'help' for the list of supported commands.
[disconnected /] connect localhost
The controller is not available at localhost:9999
[disconnected /] connect
The controller is not available at localhost:9999
[disconnected /] connect localhost:9999
The controller is not available at localhost:9999
[disconnected /]
Also i have another installation of jboss5 GA. I hope that is not interfering.
Although that is totally shut down for now.
Native management interface is :9999 in standalone.sh
Please throw light on this issue.
#
EDITED
#
When i stop my service with "service jboss stop"
i get this message
[root# bin]# *** JBossAS process (7302) received KILL signal ***
grep: /var/run/jboss-as/jboss-as-standalone.pid: No such file or directory
I Dont know how to check whether server is listening on the port 9999 or not.
Few more details
[root bin]# netstat -anp |grep 9999
tcp 0 0 127.0.0.1:9999 0.0.0.0:* LISTEN 7931/java
[root bin]# netstat -anp |grep 8080
tcp 0 0 0.0.0.0:8080 0.0.0.0:* LISTEN 7931/java
JBoss processs id and the server id acquiring these ports is same.
This question has two issues ,
First, i have provided debuging parameter in the startup script.
If you see 8787 that means you have somewhere provided debuging argument.
Second and the most important one controller not available #localhost or #IPADDRESS .
Please check if you have used port offset, as it increments all the ports by the number with with you have set port offset.
Suppose port offset is 2
Then try to access connect localhost:10001 Port i.e 9999+2
On my production server sometimes it does not works with localhost , but works with IP address.
Then try to access connect IPADDRESS:9999
OR
Then try to access connect 127.0.0.1:9999
Please check in the firewall weather the port 9999 or what ever with port offset, if the port is not open in the firewall it gives error,
I asked this question 6 months back and the above checks has solved
the problem always.
This is probaby because you have changed your binding configuration and jboss does not bind to 127.0.0.1.
In case your jboss instance is not binding to 127.0.0.1, you may use --controller option as follows:
./jboss-cli.sh --controller=YOUR_IP:9999
Use netstat -anp |grep 9999 to find out if port 9999 is in use and by which process id. You could also check the host.xml used by the controller to configure the proper native port.
In the host xml, you should find the default port:
<native-interface security-realm="ManagementRealm">
<socket interface="management" port="${jboss.management.native.port:9999}"/>
./jboss-cli.sh --controller=localhost:9999 --connect
You open the debug-port with jboss-cli.sh. Either you activated in jboss-cli.sh:
# Sample JPDA settings for remote socket debugging
# JAVA_OPTS="$JAVA_OPTS -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=n"
or you set JAVA_OPTS with such an option in you environment. See
echo $JAVA_OPTS
I guess you did this for two jboss-processes, and you get a port-conflict. See
netstat -nap | grep 8787
I recently faced this issue and the root cause that I found was completely different than it is listed above. It is because for some other project I shifted to JDK 1.8 from 1.7. Boom! and error started coming up...I took hell lot of time figuring out why it is coming up before finally realizing I changed my JDK version.
It might be because JBOSS 7 doesn't work with 1.8 of which I have limited knowledge but yes this might prove useful for some cases.

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