Yesterday all working great, but today, i went to work and tomcat didn't work. When i try to open page of tomcat, server not response, but in command line say that hi is running. I don't understand this problem. log - catalina.2016-02-09.log is very big, but not have error.
Log.
There's the likely culprit in the stacktrace:
java.net.BindException: Address already in use
That most likely means a zombie process of your tomcat was running and you started another instance.
And please, if you don't know what logs are, don't write stuff like "but not have error", there's at least two stack traces in that log.
Related
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
I just put my PC on this morning and I get the following error when starting Apache2.4 from Services:
Windows could not start the Apache2.4 service on Local Computer. Error
1067: The process terminated unexpectedly.
I went on Event Viewer to check the logs as most people were suggesting this online and that was no help either, see below screenshot of the error log:
This doesn't really point to the problem or say what the actual problem is, so my question is how can I find the actual cause of Apache not working?
I’m trying to get a mod_perl2 application ported to AWS. As part of the port I thought I’d move from Debian Squeeze to Wheezy with the latest stable mod_perl & Apache2 combination.
The application works right up to the point I try and write JSON responses to the client. At this point, each request is canceled on the client and on the server I get the error
Apache2::RequestIO::print: (103) Software caused connection abort
whenever I write to the client, i.e.:
$self->req->print($output);
I’ve tried tcpdumping the response to the client, and I can see it being written out, but no response is received on the client end and it just barfs chips. I can’t find any information on how to get around this.
I found quite a few people asking about this question on the net without many answers. The solution to my problem was very specific but I thought I’d post what I did anyway, it may help someone.
The client was canceling the request before the response was fully written, which was crapping out Apache::RequestIO (for reasons I still don’t know).
I couldn’t work out why I was seeing this behavior.
By using tcpdump I could see that data was being written out to the client – and it looked fine.
By inspecting the page in Chrome and looking at the network stack, I could see that my request for data was being canceled after no response was received (which was odd because the code worked fine on other servers and I could see the response was being written). Debugging was may harder because with Apache crashing out with an error in print IO I couldn’t check if the bytes written equaled the bytes of data. I wasn’t sure if something was getting stuck on the server side.
So, I changed the Content-Type of the response from application/json to text/html, so that I could query the page and just look at the actual response as text. Once I did that, I could see that the response was fine.
I started to look for other causes, and I found that in the migration to the new server, I’d missed altering some URLs in the DB to point to the new server, which meant my application was trying to get some data from the old DB.
This in turn was causing a load of timing issues, which was causing my problems. Once I fixed the config, the problems went away.
Redis server which was working fine got stopped suddenly and the error is:
BeginForkOperation: system error caught. error code=0x00000000, message=Forked
Process did not respond in a timely manner.
Not able to figure out why it is happening, and also when I am restarting my machine then
if I start the redis-server it's working fine.
Please help me in this regard.
You should try updating your Redis version, the guys from MSOpenTech fixed a lot of bugs in the last months and this one looks related, at least the error message is identical: https://github.com/MSOpenTech/redis/issues/144
I have created a web application in Apache Cocoon.This website is running properly but after every 3-4 days, it stops responding. It doesn't run until and unless, we restart the tomcat service. In the catalina.2011-05-09.log file, it shows following error:-
"May 9, 2011 3:17:34 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/webresources] is still processing a request that has yet to finish. This is very likely to create a memory leak. You can control the time allowed for requests to finish by using the unloadDelay attribute of the standard Context implementation."
I am not been able to understand the cause of this problem. Can someone suggest me how to resolve this issue?
You are using a library that is starting one or more threads and is not properly shutting them down or releasing other resources captured by the thread. This often happens with things like Apache HTTP components (I get this error with Http Components) and anything that uses separate threads internally. What libraries are you using in your Cocoon application?
It is telling you the issue:
[...] is still processing a request that has yet to finish
You need to find out what that request is/is going to. One easy way is to have something like PsiProbe installed.
Also, it's not a bad idea to restart Tomcat every night. It can help alleviate these kinds of issues until you find the root cause.