XX:OnOutOfMemoryError on setenv.sh - jvm

i want to set a script which will restart the server automatically.
And i write the following code to setenv.sh file
JAVA_OPTS="$JAVA_OPTS -XX:OnOutOfMemoryError=/usr/local/apache-tomcat-5.5.30/bin/shutdown.sh;/usr/local/apache-tomcat-5.5.30/bin/startup.sh;"
It not working properly.
I am using tomcat 5.

To answer your question - I don't think the error handler can run several commands. If you want to do this, then write a small restart script and run your custom script.
However, I would think about this again. Not every OutOfMemoryError means the server should be restarted automatically. You'd better to get a notification and then profile the server to get the cause of the OOME, so you can get rid of it.
P.S
Any reason to use the old tomcat 5.5? tomcat 7 is quite mature.

Use CATALINA_OPTS instead
CATALINA_OPTS="${CATALINA_OPTS} -XX:OnOutOfMemoryError=\"/bin/sleep 30;/bin/kill %p; /bin/sleep 60; /bin/kill -9 %p\""

Related

how to properly see the errors of a flask application in production mode

I have made a flask application at my local computer in the debugging mode and it runs all fine. But when it comes to production, the website gives me 500 or internal server error, which I have no idea what the bug is. I am fairly new to flask production and this has been stopping me from moving forward for quite a few days.
My questions are:
1> in my local development environment, one could always print things out. But how can I see those prints in the production stage?
2> Do I see them through Apache2 log? Where is Apache2 log?
For production, I actually followed the tutorials from pythonprogramming.net. Youtube link is here:
https://www.youtube.com/watch?v=qZNL4Ku1UQg&list=PLQVvvaa0QuDc_owjTbIY4rbgXOFkUYOUB&index=2
To use a very simple example, if the code imports a package which wasn't installed, where can we see the errors?
Thanks in advance.
I've tried to use to use try ... except block for every flask function. Whenever there is an exception, it can be return to the front-end. But what about other errors?
I found out:
Use logging module
Read apache2 log from /var/log/apache2

Apache not starting, fails silently/hangs

I had a web server that got overloaded. I attempted to stop apache but it just hung so I kill -9 the apache pid.
When trying to run
sudo /etc/init.d.apache2 start
or any derivative thereof, nothing happens. The command doesn't return. There is no error in log or at command line. I just get Starting web server: apache2 and the cursor keeps blinking. I've waited 30 minutes and still nothing. The server has 10G of memory free.
I running Debian wheezy.
Start by looking at the log files. That should contain the reason.
If there is nothing in the log files, troubleshoot using strace shown here : https://serverfault.com/questions/150249/best-way-to-troubleshoot-apache-not-starting
strace showed it was hanging on an nfs4 mountpoint that was not functioning properly.

Unable to open debugger port in IntelliJ IDEA

I have a problem that I can not set up my application in debug mode with IntelliJ IDE, but run mode is OK.
My OS is Windows 7, IDE is IntelliJ IDEA, web container is Tomcat 6. I have tried for a long time, changed the HTTP port and the JMX port, but it did not work.
When I set up the app in debug mode with IntelliJ, it failed and the event log is:
16:05:35 Error running tomcat: Unable to open debugger port :
java.net.BindException "Address already in use: JVM_Bind".
the key to the issue is in debugger port. I was having the same problem, I was killing every process listening on port 8081 (my http port), 1099 (JMX port), tomcat shutdown port, every java.exe, and still nothing.
The thing is this debugger port is different. If you run the application, it will go through the port you have Tomcat configured for, 8080, 8081 or whatever. But if you run it in Debug mode, it goes through a different port.
If you go edit your Tomcat configuration from IntelliJ, the last tab is Startup/Connection. Here go see the configuration for Debug mode, and you'll see its port. Mine was 50473. I changed it to 50472, and everything started working again.
If you're on windows you can bypass the socket issue completely by switching to shared memory debugging.
For me, IntelliJ Event Log (right bottom corner) had below logs:
Error running EntitmentTooling-Debug: Cannot run program "/path-to/apache-tomcat-8.5.15/bin/catalina.sh" (in directory "path-to/apache-tomcat-8.5.15/bin"): error=13, Permission denied
Error running EntitmentTooling-Debug: Unable to open debugger port (127.0.0.1:58804): java.net.SocketException "Socket closed"
The command
$ chmod a+x /path-to/apache-tomcat-8.5.15/bin/catalina.sh
to sufficiently change privileges worked for me.
I have encountered the same error while using IntelliJ. Since I have started multiple instances of IntelliJ. While starting two instance it started properly. However, when starting another one, it was giving below error.
unable to open debugger port (127.0.0.1:debug-port-number) java.net.socketexception interrupted function call accept failed
There are basically two places you can check your ports related to debugging in IntelliJ
JMX port - you can find this is
In Startup/Configuration, there is debug option just click this.
What to Check: If IntelliJ is throwing above error, means issue is any of the above listed ports. To verify this open event log (its available in right corner down) and check the exact message. Event log will have message like below
11:19 PM Error running 'Tomcat-tp': Address localhost:1098 is already in use
11:19 PM Error running 'Tomcat-tp': Unable to open debugger port (127.0.0.1:51787): java.net.SocketException "Interrupted function call: accept failed"
Solution-1
Check the JMX port of current intelliJ which is not starting with the working one and verify if JMX ports are not duplicated within IntelliJ instance or any of the software which is running in your machine is not using this port.
Solution-2
If JMX is not duplicated then verify your debug port, check in all IntelliJ instance and do the changes.
Surely either JMX or Debug port is having issue just use unique JMX and Debug port and it will work.
Hope this will help someone.
This works for me consistently (it happens to me from time to time, when I do things such a restart tomcat when I am running the integration tests, for example)
1) Find the process that has the port 1099 open
sudo netstat -anp | grep tcp | grep 1099
cp6 0 0 :::1099 :::* LISTEN 9857/java
2) kill it
kill 9857
3) Start Tomcat.
I had same issue in windows 7 and IntellijIdea 14.
I killed the java processes by going CTRL+ALT+ESc, find java and kill it.
Now Re-Run, the application again it should be fine..
You can also do it with command line or shell(linux), but I found this easier for myself
I solved the issue by this way.
I tried to kill all the java.exe processes but it was useless.
Then I tried deleting the Tomcat server
I re-deployed the project and restarted the project and it worked.
See these links for more information:
Delete Tomcat
Add a new Tomcat
I had this exact message.
The reason was that some IDE (I use Eclipse and Intellij) failed to shutdown the tomcat server. Or maybe crashed before it could do so.
The solution was to navigate to C:\...\apache-tomcat-xxx\bin and run shutdown.
All the other solutions unfortunately did not work.
This is what worked for me . I simply changed the debugger port to some other port number.
Intelij-> preferences->Build, execution, deployment ->Debugger-> Built in server->port(change value )
It happens occasionally that when I restart my computer, everything is OK. Perhaps there is a port conflict.
Restart the computer works because instances of Java or Tomcat are killed during the restart. You can also consider killing the specific processes from Task Manager
This also happens if there is an issue in the context.xml file. In my case, I had accidentally changed the context value.
I have the same issue,because my computer's DNS miss 127.0.0.1 localhost.
When I add 127.0.0.1 localhost to my host file,it become ok.
While debug I got this issue: It worked with
tried changing my Tomcat http port 8082 to 8083(In debug
configurations on IntelliJ and in Tomcat->conf->server.xml also)
tried changing JMX port from 1099 to 1009.
tried changing debug port in Startup/Connection in debug
configurations
killed all java processes in TaskManager->Processes.
There are various reasons for this.
- There might be the problem with debugger port---Please change it to resolve( answered by T.M )
- There might be some issue with intellij cache --Invalidate cache and restart will solve it ( answered by feng smith )
- There might be problem with any other Port, like JMX, AJP --- Please change these port numbers as well.
I wanted to add this as comment but not enough rep
My fix was the change debug port from 54444 to 7070
None of above methods worked in my case i.e. changing port number in run configuration, machine restart, invalidate cache in IntelliJ, killing process shown in netstat (nestat -anob | findstr <port-number> and then tskill <pid>). The only thing that finally helped was starting and shutting down tomcat manually via startup.bat and shutdown.bat (you should use correspondig .sh files on linux and macOS).
The only thing that worked for me is to go to Task Manager on Windows, and end all the Java processes that is running by right click -> end Task.
Check "Run" configuration to see which port it is using (8081).
Find all the other processes using that port lsof -t -i :8081
Kill the processes on that port. kill PROCESS_ID
Run Tomcat in Debug mode.
In my case, I wasted so much time on changing debugger port but it was not the issue. Since tomcat was not able to run on the port I chose in Run configuration, I was not able to debug my service.
In Server tab of Tomcat configuration in IntelliJ, change JMX port to another number.
Change debug port of your server configured in the Intelli J.
It will be fixed.
My assumption that this exception usually occurs when Tomcat is improperly closed and still holding the ports.
Usually it is enough to kill any process listening to 1099 port. For Window 10:
netstat -aon | find "1099"
taskkill /F /PID $processId
In my case I had another project open in IntelliJ, and had Tomcat running in debug mode in that project.
Stopping that instance of Tomcat resolved the issue.
In my case, there was a problem in server.xml for Tomcat/conf folder where I had extra comment tags under another comment tag. So I think, since there was some problem in server.xml, it was not able to start Tomcat. And moreover it copies the tomcat folder from your installation directory to C:\Users\username.IntelliJIdea2017.2\system\tomcat\Tomcat_service
This happens when you have application running on the same port number. One way to do this by killing the process forcefully. Open command prompt as an admin. Run command 'taskkill /IM "java.exe" /F'. This worked for me in Windows. Let me know if this works.
Probably you get the same error message if the standalone.xml in your standalone/configuration folder cannot be found. At least I have the same error when using a WildFly 14.0.1:
Just restart the Android studio before try these all. I face same right now and i fix it by this way.
Happy coding :)
For anyone who comes here with the similar message:
Unable to open debugger port (127.0.0.1:50470):
java.net.SocketException "Interrupted function call: accept failed"
This may be caused by something completely independent, i.e. it's not a port configuration. If you're running Tomcat, for instance, it may be that you have an invalid web.xml. Check your Event Log for any previous errors:
Cannot load C:\...\conf\web.xml: ParseError at [row,col]:[480,29]
Message: The element type "param-value" must be terminated by the matching end-tag "</param-value>".
I came in this scenario and as the above answers I tried to change the port like
Edit Configuration -> Startup/Connection -> debug -> change the Port
but it didn't solve my problem cause I was running my application in debug mode so once try to run the application as normal without debug.
it solved my problem!
This problem is sometimes just because of a misconfiguration.
Please, check if you have, for example, an SSL port number defined at your run configuration. If so, and if you don't have a right configuration for it at tomcat's server.xml, then it won't be possible to start your debug session correctly, and you will unfortunately have the same error. I think this can be shown as a different error. So, this is in my opinion an idea issue also..
The solution is, removing the SSL port number value from the run configuration of the IDE.
#intellij-idea
https://stackoverflow.com/questions/tagged/intellij-idea
This occurred to me, when I was running wildfly on intellij, and I switched the branch. I stopped wildfly, built the jar using maven, tried to re run Wildfly and got the error.
I tried changing port as mentioned in the accepted answer, but didn't work. I tried to find the process running on port, but netstat command didn't find it.
I tried restarting the OS, it also didn't help.
Then I checked the configuration folder of my Wildfly set up, that's when I realised
standalone.xml got replaced by standalone.xml.tmp
renaming it to standalone.xml helped me to resolve the error.
Running IntelliJ as Administrator in Windows did the magic for me:

Rails server log not outputting immediately

We use Foreman to start all of our web processes in development.
A while back, I tried to get the ruby-debugger gem working with this setup, but I couldn't, so I abandoned my effort. Along the way, I must have changed some setting or another, and now when I try to look at the server log in real time when I make a request to my local environment, nothing gets printed out. I have to kill foreman in order to see any output from the request.
This is really slowing down my development, as I have to make a request, kill foreman to get information about what went wrong, then start up and try again.
Any ideas how to get my server log to spit out everything as I'm making requests?
I had the same problem. It's solved here:
It's as simple as adding a line
$stdout.sync = true
To your config/environments/development.rb file, then restarting foreman.
Worked for me and makes my life much easier.

CakePHP app working remotely but not on local machine

I have a CakePHP app which I have been developing on a remote server. Everything is working fine on the remote server.
I'm now trying to install it on a machine with a fresh install of XAMPP. Cake is timing out. Apache is working - other things, such as phpMyAdmin, work fine. I am running Apache through port 8000, as IIS is using port 80. The OS is Windows Server 2003.
When trying to access the app, it times out, with the following error:
Fatal error: Maximum execution time of 30 seconds exceeded in C:\xampp\htdocs\cake\libs\debugger.php on line 247
I have turned URL rewriting off, that hasn't solved the problem.
I have been trying to track down the source of the problem by echoing things and then exiting the script in the cake core. I found that the script was timing out (with the same error) when the components were trying to load. I commented out my components array in app_controller, and the script ran a little further.
Now, I have tracked it down this far:
Dispatcher::dispatch();
Dispatcher::_invoke();
Controller::constructClasses();
Controller::loadModel();
ClassRegistry::init(); //called on line 635 of Controller in the "else" block of the if (PHP5) statement
In ClassRegistry::init(), the script times out on line 141, whic is as follows:
${$class} =& new $class($settings);
I have no idea where to go from here! Help much appreciated.
I got your problem.
To solve this you should do tw0 things.
1) Try to change the debug level 2 in the core.php from the config adn then change it to 0.
2) plz enable this line from the config.
line number 57 in core.php.
Configure::write('App.baseUrl', env('SCRIPT_NAME'));
regards,
archit.
Well, after following the problem a bit further, I found that the problem was coming up in Model::construct. It turns out that the hostname in my database.php file was wrong! I would have expected a "could not connect to the database..." error.