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cannot use both TOMCAT server and my internet connection

I cannot have my tomcat server started and at the same time use internet.
either I can start Tomcat (in Eclipse) and internet is not available.
or I can access the internet but tomcat cannot be started.
Here the original probleme I had when I first wanted to use Tomcat and display my html page on localhost.
GRAVE: StandardServer.await: create[localhost:8005]: I find a way to start the Tomcat Server: in the terminal:
sudo lsof -i : 8005 # checks port 80
sudo route -n flush
sudo route add default 192.168.1.1
then I can use tomcat and localhost:8080 but my internet connexion is dead
if I want my internet connexion then I stop the tomcat server by clicking on the red square in eclipse and then in the terminal I do:
sudo route -n flush
sudo route add default 192.168.0.1
THen I can use internet but tomcat cannot be restarted. I have to undergo the first process.
this of course is a very boring process and I would like to know what 's wrong and how I could fix it.
I use tomcat 9 / Mac OS sierra / Eclipse Neon3

When you say "my internet connexion is dead", do you mean that your network connection drops or that your DNS lookups fail? (What do you think this command is doing and why are you performing it: sudo route add default 192.168.1.1?)
If your program is modifying your system's connectivity settings, I would strongly recommend against preventing it from doing that. There's no reason for it to do so at that level, a more appropriate place to set settings would be at some deploy stage.
Alternatively, you could run your app in a Docker container which I strongly suspect will solve your problem. Visit www.docker.com to learn more.

Connect JVisualVM to a Remote Wildfly Instance?

I'm trying to connect JVisualVM, running on my local machine, to a remote machine which is running a WildFly server (version 8.1.0, to be specific.)
I didn't configure the WildFly server myself, and I don't know who did, but I do know that I can log in as an administrative user from my local machine by pointing my browser at:
https://[ip address of the remote machine]:9443/console
Note that it's https, not ordinary http, and that the port for that has been set to 9443 (I think the default is 8080 or 9990 or something... IDK, I saw a lot of port numbers online. I have been explicitly told that http was disabled for this WildFly server).
I can SSH into the remote machine. I can navigate to the bin directory for WildFly and run jboss-client.sh. I have to connect on port 9999 (I think the default is 9990 for that?)
I copied the jboss-client.jar (under bin/client) to my local machine and ran JVisualVM from the command line like this:
.\jvisualvm.exe -cp:a C:\[path to]\jboss-client.jar
It launches fine. File > Add Remote Host: Then I entered the IP. OK. I right clicked on it under Remote in the tree and picked Add JMX Connection. I entered
service:jmx:http-remoting-jmx://[ip]:9999
I checked off that I wanted to use the security credentials and entered the username and password. Checked off to save the security credentials. Left "Do not require SSL Connection" unchecked. Hit OK. It immediately spat out the message
Cannot connect to admin#service:jmx:http-remoting-jmx://[ip]:9999 using service:jmx:http-remoting-jmx://[ip]:9999
I also tried the port 9443, 9990, and 8080 instead. None of those worked. I tried https instead of http in the protocol name. That also didn't work.
What am I missing? How is it that I can access the console, and connect with jboss-client.sh, but I can't use JVisualVM? Is there some log I can use somewhere to see what's wrong? Maybe someone can point out a configuration I've missed somewhere?
Not sure if it's important or not, but my local machine is running Windows 10 with JDK8 installed. The WildFly server is using Java 6 on CentOS 6.3.

You need to add the jboss-client.jar (or jboss-cli-client.jar) to the class path for JVisualVM. The library can be found in the bin/client directory of the WildFly install.
I used the following command to add the library to the class path.
jvisualvm --cp:a ~/servers/wildfly-10.0.0.Final/bin/client/jboss-client.jar
Then I used service:jmx:remote+http://[ip]:[port] and was able to connect.

I don't know if someone else is also (still) having the same issue (Wildfly10 on a remote machine where management console is available at 9443 with HTTPS). The following worked for me.
For ssh connections:
Starting jvisualvm with jboss-client.jar
jvisualvm --cp:a #JBOSS_HOME/bin/client/jboss-client.jar
Using the following connection string:
service:jmx:remote+https://remote-server:9443
NOTE: I used here remote+https
Provide username and password
Hope this helps.

you missed run jstatd command in remote host ,
this little program is RMI server that possible connection from client to remote host though you using jmx connection it used jmxrmi protocol for that connection .
so first in remote host create file name as security.policy with this contain :
grant codebase "file:${java.home}/../lib/tools.jar" {
permission java.security.AllPermission;
};
off course you must in file section for linux put explicit path and then of creation this file put it in bin directory of jdk.home
then you should run this command on remote host
$JAVA_HOME/bin/jstatd -J-Djava.security.policy=path of /security.policy -J-Djava.rmi.server.hostname=remote ip address -J-Djava.net.preferIPv4Stack=true
then you could connect to server off course with correct settings.

Include jboss-cli-client.jar and jboss-client.jar under \lib\visualvm\platform\lib and restart jvisualvm to pickup new jars.

Rabbitmq exception com.rabbitmq.client.PossibleAuthenticationFailureException: Possibly caused by authentication failure [duplicate]

I've installed the latest RabbitMQ server (rabbitmq-server-3.3.0-1.noarch.rpm) on a fresh Centos 5.10 VM according to the instructions on the official site.
I've done this many times before during development and never had any issues. However, this time I cannot log into the management web interface using the default guest/guest user.
In the logs, I see the following:
=ERROR REPORT==== 4-Apr-2014::00:55:15 ===
webmachine error: path="api/whoami"
"Unauthorized"
What could be causing this?

It's new features since the version 3.3.0
http://www.rabbitmq.com/release-notes/README-3.3.0.txt
server
------
...
25603 prevent access using the default guest/guest credentials except via
localhost.
If you want enable the guest user read this or this RabbitMQ 3.3.1 can not login with guest/guest
# remove guest from loopback_users in rabbitmq.config like this
[{rabbit, [{loopback_users, []}]}].
# It is danger for default user and default password for remote access
# better to change password
rabbitmqctl change_password guest NEWPASSWORD
If you want create a new user with admin grants:
rabbitmqctl add_user test test
rabbitmqctl set_user_tags test administrator
rabbitmqctl set_permissions -p / test ".*" ".*" ".*"
Now you can access using test test.

If you still can't access the management console after a fresh install, check if the management console was enabled. To enable it:
Go to the RabbitMQ command prompt.
Type:
rabbitmq-plugins enable rabbitmq_management

Something that just happened to me and caused me some headaches:
I have set up a new Linux RabbitMQ server and used a shell script to set up my own custom users (not guest!).
The script had several of those "code" blocks:
rabbitmqctl add_user test test
rabbitmqctl set_user_tags test administrator
rabbitmqctl set_permissions -p / test ".*" ".*" ".*"
Very similar to the one in Gabriele's answer, so I take his code and don't need to redact passwords.
Still I was not able to log in in the management console. Then I noticed that I had created the setup script in Windows (CR+LF line ending) and converted the file to Linux (LF only), then reran the setup script on my Linux server.
... and was still not able to log in, because it took another 15 minutes until I realized that calling add_user over and over again would not fix the broken passwords (which probably ended with a CR character). I had to call change_password for every user to fix my earlier mistake:
rabbitmqctl change_password test test
(Another solution would have been to delete all users and then call the script again)

If on Windows and installed using chocolatey make sure firewall is allowing the default ports for it:
netsh advfirewall firewall add rule name="RabbitMQ Management" dir=in action=allow protocol=TCP localport=15672
netsh advfirewall firewall add rule name="RabbitMQ" dir=in action=allow protocol=TCP localport=5672
for the remote access.

I also couldn't log in to Rabbit's web interface. in my case, cookies were disabled in the browser for this web interface. I allowed cookies to be saved and rebooted chrome. and I was able to log in again.

If you are in Mac OS, you need to open the /usr/local/etc/rabbitmq/rabbitmq-env.conf and
set NODE_IP_ADDRESS=, it used to be 127.0.0.1. Then add another user as the accepted answer suggested.
After that, restart rabbitMQ, brew services restart rabbitmq

GlassFish Server: Administrator port is occupied by null

I tried to start glassfish server via the Netbeans IDE but it showed this error:
Could not start GlassFish Server: Administrator port is occupied by null
C:\Users\Ateeq Khaliq\Documents\NetBeansProjects\WebApplication1\nbproject\build-impl.xml:1045: Deployment error: Could not start GlassFish Server: Administrator port is occupied by null
See the server log for details.
BUILD FAILED (total time: 2 seconds)
I have changed the port also to 9999 in C:\Users\Ateeq Khaliq\GlassFish_Server\glassfish\domains\domain1\config file.
How can I fix this?

Change this
the solution is change the host configuration

netstat -aon | find ":4848" | find "LISTENING"
Kill the process that is using your Administrator port

Its seem to be a Bug in Netbeans
if you have alraidy found a solution please let me know.

I had the exact same problem and the way I solved it was to delete the glassfish, tomcat7 and tomcat 8 servers from my IDE. I then deleted their folders on my hard disk and reinstalled the glassfish alone. Everything worked fine after that.

If Netbeans is blocked by Firewall this happens. Make sure your Antivirus firewall is not blocking NetBeans. Grant NetBeans full access to act as a server (This is also asked when you start NetBeans).
Then you should be able to start your server through NetBeans

remove glassfish server from Netbeans and added another one click Tools-servers
select your server and click remove servers and click add servers change the domain name and change port from 8080 to 8090 as you like. restart Netbeans

It has a really simple solution, just restart the Java process in your machine and you should be good to go..

Error while running webapplication with google appengine

I created a small web application.if i deployed its work but if try to run application it show
the port 8888 appears to be in use(perhaps by another lanch),do you still to contine with this lanch? i clicked yes
but show the error
Could not open the requested socket: Address already in use: bind
Try overriding --address and/or --port.

The problem is what it is stating.
You are facing this issue because of the following:
Either the port 8888 is in use by some other application and not previous launch. This is less likely.
This condition is more likely and it is because you have already launched the application once i.e. via the Run as Web Application. And it is still running. In your Eclipse, visit the Window-> Show View -> Console. And in the Console window, you will find one or more previous instances running. Please stop that.

There are some instances where the solution suggested by Romin will not work because the option to stop the process does not present itself in the console.
In these cases, you can probably find out which process ID is using the port and then kill that process.
For example, on a mac, this worked for me:
😈 >lsof -i tcp:8888
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
java 25866 alexryan 60u IPv6 0x96e9c26778f105e1 0t0 TCP localhost:ddi-tcp-1 (LISTEN)
😈 >kill 25866
😈 >lsof -i tcp:8888
😈 >

The port number 8888 is in use means that port already been activated. do one thing go to servicees option of control panel set the server start option from automatic to manual. Then your apps will get run. else you can stop the server from your eclipse env stop option.