Web application no longer responds

We have developed a web application for document management and installed it on linux server; it works fine.
Some times, the web app no longer respond to the browser and in the web browser appear something like this “Unable to contact the server”.

Checking with “top” command, the process is alive with 3~5% of CPU and 5% of RAM of the server.
Restarting the process, all works fine.

What could be the problem because the application does not send any answer to the browser?

depending on your type of build, it could be a number of things.

If CGI, you can probably rule out the app itself. This type of error would mean that the browser can’t even reach Apache or whatever other web server you are running.

If it is Standalone, then it could be the app itself.

Things to check:

  1. When an outage occurs, does it affect all users? Or just a single location?
  2. Have the app periodically log the number of sessions. I’d be curious if you are maxing out the number of connections somehow.

Application is builded as standalone.

When the outage occurs, it affects all users.
The app actually does not log the number os sessions.

Do me a favor and build another small app and have it running on the server as well. The next time you are unable to access your publishing app, check to see if you can access the second app. I’m curious to see if it is more of a system problem than related to that particular app.

For what it’s worth, if you have any tight loops in your app, that might cause this behavior. Basically the app could be unable to respond.

Also, I am assuming that your app connects to a database server. It might be worth noting if the database connection has stalled somehow. Perhaps a long running query?

Ok. I will build another app and check it next time I’m unable to access to the primary app.

Thanks for now.

I’ll keep you updated.