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Unable to start tomcat 8 on ubuntu 16.0.4 TLS

I have written an application on REST API's and deployed that on tomcat 8.0.36. When I start the application from eclipse it gives me a timeout message after 45 seconds "Server Tomcat v8.0 Server at localhost was unable to start within 45 seconds. If the server requires more time, try increasing the timeout in the server editor."
I have done all the troubleshooting stuff:
1) Deleted the server from the server perspective and re-added the server and tried to re-deploy it
2) get the same message as above.
3) I have tried by launching the tomcat without the application deployed it starts .
Regards
Vilas

To increase the tomcat boot time, you must follow the following steps:
Launch Eclipse
On Servers view, double click on you tomcat server configuration
Find the option Timeouts, this is in the top right of editor
Increase the time, for example 120.

Websockets/threads/DB connections keep failing on Wildfly

I'm currently developing a Java Websocket application that is deployed on Wildfly 10. I cannot post the code, but here's the logic:
Multiple threads poll a database every 5 seconds(select query, reusing a PreparedStatement after closing previous ResultSet) and send via Websocket to all connected clients.
Have configured datasource that connects to MYSQL server (localhost).
The application runs fine until a while later, it crashes and the log is full with 'Unable to get managed connection from datasource' errors. Also, Websocket fails with 'ClosedChannelException'.
Services on the same server that open a connection and close it immediately do work fine. However there are 5-6 threads in the concerned code that must use connections after 5 secs so a thread is given a dedicated connection that is only torn down when the application context is destroyed.
Another thing is when the application fails, it works for a lesser time on disable-enable. Only a reboot gets it to work better.
Same project works without error on Glassfish.
Somehow, Wildfly seems to periodically reset either DB connections, or all TCP connections altogether.
Is there a setting that is relevant to Wildfly's behaviour towards threads? I have verified that only as many threads as are intended are actually created.
Any help would be appreciated.
Edit: This application works well on my local machine. When I deploy it on remote server, it works for a while (3 hours max) before failing altogether.
I use Netbeans 8 to compile, if that helps.

Tomcat restarts with errors (exit 143), runs and then fails after time

This is my first time asking a question on Stack Overflow. I recently configured an Ubuntu 16.04 virtual private server to host a web application. I run ngnix on a Tomcat server that reads and writes to a MySQL database. The application runs fine except for the fact that Tomcat restarts itself once in a while which results in a 500 error that stems from a "broken-pipe" when anyone tries to login (i.e. make a connection to the database).
I will post an image of the 500 next time it happens. I went into my vps and looked at my Tomcat restart message. This is what I see: Tomcat status message.
I also did a little diving into the Tomcat logs and this is a log file that corresponds with that restart time: Tomcat log file
I did some research to try and solve this myself, but with no success. I believe that the exit=143 is the process being terminated by another program or the system itself. I also have done some moving of the mysql-connector-java.jar. I read that it should be located in the Tomcat/lib directory and not in the WEB-INF of the web application. Perhaps I need to configure other settings.
Any help or any direction would be much appreciated. I've fought this issue for a week with having learned much, but accomplished little.
Thanks

Look at the timeline. It starts at 19:49:23.766 in the Tomcat log with this message:
A valid shutdown command was received via the shutdown port. Stopping the Server instance.
Exit code 143 is a result of that shutdown and doesn't indicate anything.
The question you need answered is: Who send that shutdown command, and why?
On a side note: The earlier messages indicates that Tomcat lost connection to the database, and that you didn't configure a validation query. You should always configure that, since database connections in the connection pool will go stale, and that needs to be detected.
Theory: Do you have some monitoring service running that tests your application being up? Does that monitoring detect a timed-out database connection, classify that as a hung webapp and auto-restart Tomcat?

While I don't think I am able to see to the core of the problem you have with your overall setup given the small excerpt of your log files, one thing strikes the eye. In the Tomcat log, there is the line
A valid shutdown command was received via the shutdown port. Stopping the server instance.
This explains why the server was restarted. Someone (some external process, a malicious attacker, script, or whatever. Could be anything depending on the setup of your server) sent a shutdown command to Tomcat's shutdown port (8005 by default) which made the Tomcat shut down.
Refer to OWASP's recommendations for securing a Tomcat server instance for fixing this possible security whole.
Regarding the ostensible Hibernate problems you have, I don't get enough information from your logs to make a useful statement. But you can leave the MySQL jar in Tomcat/lib, since this is not the root cause of your problem.

Why isn't RAD (Eclipse) able to properly detect WAS server startup?

If I start WAS 6.1 under RAD 8.0.4.1, I see the server start in the console:
[9/24/12 17:21:18:671 EDT] 0000000a WsServerImpl A WSVR0001I: Server server1 open for e-business
RAD continues to indicate that it's waiting for server startup in the progress pane: "Starting WebSphere Application Server v6.1 at localhost". This is a pain because it eventually times out and tells me the server never started even though it's running and responding to requests and it seems like this state means publishing updates as I change code fails to work.
I don't see any errors in the console during server startup - same for the WebSphere 6.1 Launcher's console.
Is there a simple way to fix this?

This question I believe has been asked a few times.
Read this technote and see if any of those suggestions help
http://www-01.ibm.com/support/docview.wss?uid=swg21207553
HTH

CLI Application Unknown error in Java

I wrote a socket client in java that 24/7 connected to a socket server and receive data from it.
the client is running for about 3 days in testing, everything looks fine, and than suddenly I saw this message in the eclipse console (No stack trace):
ServerCommunicatorAdmin reqIncoming
The server has decided to close this
client connection.
I restart the application and now its working again.
I asked the server sysadmin, he says that everything looks fine the his logs.
my system uses mysql jdbc and log4j.
Any idea what can be the source?
Thanks

If you Google ServerCommunicatorAdmin you'll see that it's part of JMX
com.sun.jmx.remote.internal:
ServerCommunicatorAdmin.java
and if you search for "reqIncoming The server has decided to close this client connection" you get lots of hits. There should be something in there to help you.