I am in the process of developing a java web application, and am using the web framework Spark which utilizes Jetty (An http server written in java created by eclipse). Spark makes use of Jetty's embedded webserver functionality, essentially creating a Jetty instance within the app. When creating an executable jar of my application and running on windows, all is well and I can connect to my app locally through http://localhost:81 (I am using port 81). Eventually, I'd like the app to run on a linux server, but upon executing the jar on ubuntu, I am unable to connect to the app locally. I only have a moderate understanding of linux, and cannot figure out why this is happening. I am executing the command 'java -jar G2.jar &' in screen, and it seems to be executing properly. I have ensured that the JDK on ubuntu matches the version installed on my windows machine. I have been testing on an AWS ec2 ubuntu instance and an ubuntu vm, and have had no luck on either.
wget:
wget 127.0.0.1:81
--2016-10-24 21:10:24-- http://127.0.0.1:81/
Connecting to 127.0.0.1:81... failed: Connection refused.
curl:
curl 127.0.0.1:81
curl: (7) Failed to connect to 127.0.0.1 port 81: Connection refused
I have flushed iptables, and even disabled ufw with no luck. Both the ec2 instance and vm are fresh ubuntu installs. I am beginning to think the problem is within Jetty, and that it possibly requires different configuration on linux? The issue is, Spark handles the embedded Jetty instance, and I am unfamiliar with how it does so. Has anybody dealt with this type of issue before?
I fixed the issue. I figured that using the '&' at the end of the command to run the app as a background process would work fine, but guess it does not. Instead, I just used sudo without the '&' and it works now.
Related
I’m using glassfish 3.1.2 on Red Hat Enterprise Linux Server release 5.7 (Tikanga). Glassfish has been installed as part of a piece of bigger software (that I’m developing). It used to work correctly in the past.
I can issue a ‘start-domain’ command. This one will work correctly and glassfish will start. I can see the process and the glassfish admin web console is working fine. However, the command ‘list-domain’ reports my domain as not running. The command ‘stop-domain’ will fail reporting the domain1 as already stopped. This prevents my software to run properly.
As far as I know, nothing has changed on that system. There is no exception/error in the log. I already search the internet for description of similar behaviour. I ensured the embedded firewall (the one coming with the OS) did not prevent the communication. I removed the expired certificate (just in case). I have no idea on what I could do next.
What could I check? Any help appreciated. Add a comment if you need specific details and I will update the question.
Answer to unwichtich's questions:
absolute path to jvm using an absolute path to the admin-cli.jar: /.../java -Duser.home=... -Duser.language=en -Dhttps.protocols=TLSv1.2 -jar /.../glassfish/modules/admin-cli.jar --terse --port 23992 --user admin --passwordfile /.../passwordfile list-domains
There are two lines in the /etc/hosts. The first with the ip mapping to the hostname. The second with 127.0.0.1 mapping to loopback and localhost
My software includes some command line utilities that need to perform operation on Glassfish (like start-domain, stop-domain, list-domains,...).
I'm trying to figure out how to debug my jar that is running remotely. Here is my scenario:
My .jar will be running from a VPS. This jar basically runs a server
for a game, so it also connects to a mysql db. I start the server with 3 .bat files that looks something like this:
set CLASSPATH=.;dist\aries.jar;dist\mina-core.jar;dist\slf4j-api.jar;dist\slf4j-jdk14.jar;dist\mysql-connector-java-bin.jar
java -Xmx500m -Dwzpath=wz\ -Djavax.net.ssl.keyStore=filename.keystore -Djavax.net.ssl.keyStorePassword=passwd -Djavax.net.ssl.trustStore=filename.keystore -Djavax.net.ssl.trustStorePassword=passwd net.world.WorldServer
pause
What I want to do is start the server on the vps like normal, but debugging the server on my local machine via Netbeans IDE. I don't know if this is possible because people will be connecting to the server (although, I will be debugging a test server which will only have me online).
Note: I have done a lot of searching before coming here and a lot of what I found had to do with using xdebug & php which has doesn't have much to do with my situation (I don't think)
-Thanks
There's a NetBeans FAQ page about this.
In brief:
Add the remote debugging options to your Java command. For example:
-Xdebug -Xrunjdwp:transport=dt_socket,server=y,address=8888,suspend=n
Then, use the attach debugger option in NetBeans and select your server and the port you used above (8888). It's pretty much that easy.
You may want to think about network and firewall considerations, as you may have noticed there are no passwords involved, so anyone who can connect to the port can debug your app. This could be a big security risk. Your VPS provider probably has some tools to help with setting up a secure, private connection.
how can i test from external java application that my server jboss is running ?
I've a JBoss (4.2.3) server and I want know from a stand-alone java application if that server i started or not.
Thanks!
EDIT
I don't have access to the jboss machine and the jmx console is disabled for safety reasons.
You can check inspecting the running processes if you have access to the machine where jboss is running.
If you don't have access to the machine, then you'll have to try to connect to it, checking if it's listening to the http port or if you can reach it via JMX, but then you can't be sure if it's really not running or if some firewall rule is blocking your request.
One of the possible solution if you are running on linux is to execute a shell command like
ps -ef | grep jboss >> somelog.txt
execute it using Runtime class using exec() method in Runtime and check the output of that command from your java program
Surely there might be some other better alternative , but this is just a simple thought
I know that there are many questions on this topic, and I have been searching for an answer for the past 4 months. Everyone says check host address, port, and firewall. Well I have done these items, but am still not having any success.
We are running our web application locally using Apache Tomcat 7.0.27 through Netbeans 7.2.1 and are no longer able to connect to the SMTP server to send emails. When running the application on a virtual machine located on the server, there is no issue connecting. We have no problem connecting and sending mail using telnet locally with the same parameters.
We have tried looking at the SMTP logs on the server, and were able to access some logs, but can't find any related to the refused connection. Which SMTP logs would provide more information on this issue? I tend to think that since the connection is refused it may not even trigger any logging, is this a correct assumption? We migrated to IIS7 several months ago and were having trouble accessing IIS 6.0 Manager, so I am not sure that they are even set up correctly.
Does anyone have any ideas of how to further troubleshoot the connection?
Thank you in advance, and please let me know if I can provide any further information.
Almost certainly this is a problem with a firewall or anti-virus program on your local machine. If you can connect from that machine using telnet but can't connect from that same machine using a Java application, there's something on that machine preventing Java applications from connecting.
I recently faced the same problem while running the Mail sending code and what I found is that the code which I had written recently is using the Java version Jre7. But the older codes run in Jre 6 environment, which works perfectly even now also.
So what I had done is I just change the Jre version of my recent code to Jre 6. After that the code works perfectly without any exception.
So try to change your runtime environment to lower Jre and run the code.
I'm trying to see if a WAR I just built is even running inside of Tomcat (7.0.19). I am deploying to a linux box and so my only two options are the Tomcat admin console (web app) or, hopefully, determining webapp status through the terminal.
I already know how to get in through the console web app; I am wondering if there is any way to see the status (ACTIVE/INACTIVE/TERMINATED, etc) of deployed web apps from the terminal.
Thanks in advance.
PSI-Probe is a great application for monitoring your applications deployed to a tomcat instance. It will tell you if an application is running or down. If the application is not deployed, it will simply not be in the list.
curl --user user:pass http://localhost:8080/manager/text/list
It prints
OK - Listed applications for virtual host localhost
/manager:running:0:manager
/docs:running:0:docs
/examples:running:0:examples
/host-manager:running:0:host-manager
/myapp:running:0:myapp
Your user needs the manager-script role. Documentation: Manager App HOW-TO, List_Currently_Deployed_Applications
You can probably do it using JMX.
Find appropriate MBean that shows this information on local tomcat using regular JConsole. If you want to connect JConsole to remote you will probably have some problems with firewall, so you have other solution.
Take command line JMX client and run it on the monitored host through SSH terminal. I used the following command line JMX client: cmdline-jmxclient-0.10.3.jar
wget http://<username>:<password>#<hostname>:<port>/manager/list -O - -q
(Not sure about Tomcat 7 though)