I have a local machine , say A with IP (a.a.a.a) and a linux server, say B with IP (b.b.b.b)
Now I have created a war file with name 'example' and deployed it in Apache tomcat in our linux server.
I want to open the browser in my local machine by typing the following in address bar :
http://b.b.b.b:8080/example
But I am not able to open it.
Could any one please suggest where in lies the issue?
Note : We can connect from A to B using only VNC viewer and not able to connect it through remote desktop connection application.
Does this implies that there is some issue in network connectivity or what? I think as we are able to connect B using VNC viewer, the problem should not be there.
Please help.
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extended
I have installed the apache tomcat server in my linux server which doesnot have any internet connecttion and deployed the war file in the server successfully.
and want to open browser from my local machine using (linux_IP)//8080//war_file_name
Note : local machine connects linux server through VNC only.
Could any one suggest is it possible in this scenario?
If you can only open server B using VNC, then there is a definite possibility that port 8080 is not open. The port 8080 should be open on the server. To check that you could try :
telnet host port
so for you:
telnet b.b.b.b 8080
from your machine.
Another thing to do is to start tomcat with IP address of your linux server to listen. Start tomcat with parameters:
-b b.b.b.b (ip address of your linux machine).
To me if definitely feels like a firewall problem.
Related
I am trying to start H2 in server mode to connect an application from another computer. But no matter how hard I have tried, I have not succeeded.
I have seen the documentation and to start the server from the command line is executed:
java -cp h2-2.1.214.jar org.h2.tools.Server -tcpAllowOthers
output:
TCP server running at tcp://127.0.1.1:9092 (others can connect)
PG server running at pg://127.0.1.1:5435 (only local connections)
Web Console server running at https://127.0.1.1:8082 (others can connect)
now from the other pc, as I understand I must execute the connection in the following way:
jdbc:h2:tcp://[server][:port]/[path]/[databaseName]
then it should be:
jdbc:h2:tcp://127.0.1.1:9092/home/mateo/database
But I have read that 127.0.1.1 only works locally. I have also noticed that when I open H2 Console in the examples I have seen, the machine's ip appears, that is to say: 192.168.X.
What am I doing wrong?
(Update)
I am currently using Linux.
I have launched the server from Windows and managed to connect it from Linux successfully following the above steps. But, I still don't understand why it doesn't work in Linux, in Windows it loads the server with the IP address of the machine. It makes me think that I have to do some additional configuration for Linux.
server running
You need to replace local IP address in your JDBC URL with real non-local IP address of your server (jdbc:h2:tcp://127.0.1.1:9092/*** -> jdbc:h2:tcp://192.168.1.4:9092/***, for example). H2 listens all network interfaces of the host, it doesn't matter which address was reported in “runnig at …” message.
You also may need to protect ports 8082 and 9092 from connections from untrusted systems if you have them in your internal network and from connections from external network (make sure your router or whatever you have doesn't redirect connections to the host with database server).
I deployed my app on Heroku. It is a simple app that will throw back the message sent from its client version (running on my PC) back to the client. My server app prints the IP address of the machine it's running on so I can connect to it from my client . I do get to see the IP address of Heroku machine when I deploy and run it. However, I am not able to connect to it from my client version using that IP address(Connection timed out) . I have allowed the port I am using in my firewalls. I don't understand what I am doing wrong .
Pls help me solve it.
If you need to see my code let me know ( the app works fine locally on different terminals so I don't think it has a problem).
Your Heroku dyno (an isolated server) is behind a router. You can't use the IP address to connect to it.
Instead, you the URL https://[appname].herokuapp.com where "[appname]" is the name of your app.
You can also run heroku open from the command line.
I have a tomcat7.0 running in a remote desktop machine say 204.34.34.45.
When I log into the remote desktop and try "http://localhost:8080" it is working fine.However
http://204.34.34.45:8080 is not working.
I am able to ping 204.34.34.45 from outside the remote desktop machine.
Do you know how can I access tomcat outside the remote desktop machine.
The firewall rules for that host may not allow connections to 8080. Talk to your system administrator for details.
Also, make sure you have the correct IP bindings set up for tomcat. It is possible to allow connections to localhost:8080, but disallow them from 204.34.34.45:8080. See How do you configure tomcat to bind to a single ip address (localhost) instead of all addresses?
I have an Android application that connects to a servlet in a Tomcat server.
I have Tomcat server coupled to eclipse.
The IP address indicated to the Android application to connect to the Tomcat servlet is
http://10.0.2.2:8080/Middleware/UsuarioServlet
Why if I put
http://localhost:8080/Middleware/UsuarioServlet
not work and gives an error? If I have installed Tomcat on the same machine should work with localhost too.
Because your Android application runs on virtual device, which has another IP in your local intranet, it isn't localhost.
Localhost refers to the Android device in this case. Use the IP address 10.0.2.2 to refers to your development machine. Read more about here!
Sorry for this question which must have been asked many times, but I can't succeed in resolving my problem.
I've read a lot of blogs, sites, forums, .... and didn't find any solution in my case.
Case :
I need to connect VisualVM on my box to distant servers (tomcats, weblogics) for performance / threads / memory monitoring.
Those servers are installed on (physical or virtual) machines which are protected by a firewall.
Large intervals of ports are open in the firewall and can be used, but not all ports.
Tests
I've tried direct connections through JMX in VisualVM, using following JVM options on the server-side at server startup :
-Djava.rmi.server.hostname=[hostname]
-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=[port]
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false
I've precised the hostname because from my network the hostname and the IP address of the server are not the same than those from the network of the remote server.
No success, VisualVM always seems searching for an unknown server.
tried starting jstatd on the server-side on a port accessible (-p option) from my box (telnet on this port works), but when launching visualVM on this host with the jstatd port, it still seems waiting for something unreachable.... Same behavior with jps connecting to this remote host.
tried using the same tools on a server with less network protection, and it works. So I have seen the connections between my box and the server and they are done on ports different from what I've specified to jstatd.
I understand that this port is needed for first communication (kind of handshake) and real communications are done on other ports, but not predictible (ex: 60305, 55197, ...).
Not sure I understand very well how RMI works.
Please, help me, I'm going crazy !
Unfortunately JMX tries to open ports other than the one you configure. Just yesterday I succeeded connecting to tomcat behind firewall via JMX. The two tricky parts are:
put a file called jmxremote.access in CATALINA_HOME/conf, which contains the following lines:
monitorRole readonly
controlRole readwrite
in server.xml set the ports that will be used by jmx, via a special tomcat listener (catalina-jmx-remote.jar required in /lib):
<Listener className="org.apache.catalina.mbeans.JmxRemoteLifecycleListener"
rmiRegistryPortPlatform="9009" rmiServerPortPlatform="9010" />
Then open these two ports on the firewall. It works. But that's just for tomcat.
Another option is to use ssh tunnelling. In short - you connect via SSH and configure it to forward some local port (where the jmx client is running) to some ports on the other side of the tunnel.
References:
Connecting to JMX on Tomcat 6 through a firewall
Connecting MySQL server on Amazon EC2 instance using ssh tunnel
Here are the steps to do this:
Launch an ejstatd in your remote host this way (in ejstatd folder): mvn exec:java -Djava.rmi.server.hostname=[remote_host_name] -Dexec.args="-pr 1099 -ph 1100 -pv 1101" (used for "jstatd" type connection)
Launch your Java application with those additional Java parameters: -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.port=1102 -Dcom.sun.management.jmxremote.rmi.port=1102 -Djava.rmi.server.hostname=[remote_host_name] (used for "JMX" type connection) (java.rmi.server.hostname is required here only because the IP and hostname from your network is not the same as the server point of view)
Open those 4 ports on your remote host and make them available to your local machine: 1099, 1100, 1101 and 1102
Launch JVisualVM
Right-click on "Remote" > "Add Remote Host..." and enter your remote host name in "Host name" (if you don't use the port 1099, you can change this in the "Advanced Settings")
Right-click on the remote host you've just created > "Add JMX Connection..." and enter "[remote_host_name]:1102" in "Connection" input, and check "Do not require SSL connection"
Your Java process will appear twice: one from the "jstatd" connection type, and one from the "JMX" connection type.
Disclaimer: I'm the author of the open source ejstatd tool.
On your [hostname], open up [port] and tcp port range 40000-60000 for your IP only.
This did the trick for me fairly well.