Symbol table overflow run time error in rails - ruby-on-rails

I am running my application which is developed using Ruby 1.9.2, Rails 3.0.8 and MySQL 5.1 in development environment as i have problem with config.cache_classes in production environment.
Application is running fine, but after a day or two i am getting symbol table over flow run time error. After restarting the server then the application is running as usual.
Can any body help me out why this symbol table overflow run time error is coming and how to resolve it.

This can happen if you mistakenly leave class caching disabled in production.
Your rails config/environments/production.rb should have:
config.cache_classes = true
Thanks

Related

Rails 5 Debug in Production Mode

I am trying to find a way to check logs or debug in production I am using passenger and apache and ubuntu as server. Every time I create any scaffold and upload it to server I get error :
I have used
bundle exec rake assets:precompile RAILS_ENV=production
But getting no success but when I am running application using :
rails s -e production
I can access my controllers and views over port 3000. What is wrong with this why assets:precompile is not working properly I am adding JS files manually not using coffee script. And my javascripts files are not complied.
My question is how can I set anything in production to see a debug like in development mode like this:
Can I do this in production I am using rails 5
The production error you have shown above was a 404 error. it means that the route doesn't exist or there are no controllers methods for that route or is a model not found error.
As for adding debuggers in production, can you do it?
Yes you can.
But should you do it?
NO, because it is a BAD practice. If you wish to view and debug errors in production, check your logs for the stacktrace and work with it from there. As long as it is a rails error, it will be in log/production.log.

Rails app deploy on Heroku

I'm new in rails app development I am little bit confusing about rails deployment.
I following this guide below and done at all.
That mean my rails app on production mode?
Need to change Puma RACK_ENV to 'production' in Profile before pushing to heroku?
https://devcenter.heroku.com/articles/getting-started-with-rails4
I believe so. The entire tutorial is setting up your rails server to work in production mode. Using some inductive logic, it seems that the tutorial is assuming you're in production:
"Rails 4 no longer has a static index page in production. When you’re
using a new app, there will not be a root page in production, so we
need to create one. We will first create a controller called welcome
for our home page to live:"
Indicates to me that it's assuming your rails server will be running in production.
To make doubly sure, you can check the heroku logs and look for a line that says:
Rails [your version] application starting in production

How can I debug my Rails application which encountered an internal server error?

I am using Rails 4.1 and Ruby 2.1.1 on Ubuntu.
My application is running just fine on the local development environment. When I moved everything to the production environment server, and tried the application URL, I got the following:
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
The log file (production.log) has in it something about the migrations, but nothing else.
Where do I get started trying to figure out what this is about?
From original poster:
I followed the instructions and set up an environment variable for the secret_key. It turns out Rails 4.1 cannot read it and this seems to be a known issue. So, I had to put the key directly into secrets.yml and this solved the problem

How to properly diagnose a 500 error (Rails, Passenger, Nginx, Postgres)

I'm having a real tough time diagnosing a 500 error from my application running in production. I've had it working before, but after re-deploying via Capastrano I am unable to get it going.
Here are the facts:
The server is setup with nginx + passenger, and I'm using
PostgreSQL.
Static assets are working properly, as in I'm able to access them just fine in a browser.
I can access the rails console via RAILS_ENV=production bundle exec rails console and perform Active Record actions (like
retrieving data from the db).
Within console, I can run app.get("/"), which returns a 500 error as well (after first showing the query that was run to load
the model).
The production.log file is never written to. I've set permissions 777 on it just for the hell of it. I've also set the log level to
:debug with nothing to show for it.
The nginx log (which passenger also uses) shows no indication of errors, it just notifies about cache misses.
Because nothing of use is being logged, I have no idea what to do here. I've tried setting full permission on the entire app directory with no help. Restarted the server multiple times, nothing. The database is there and rails can clearly communicate with it. I'm not sure what I did to get it to run the first time around. I just don't know why rails isn't outputting anything to the log.
Okay, I figured this out. The app ran fine in development mode, so I knew something production-specific was screwing it up. I went into config/environments/production.rb and changes these settings:
# Full error reports are disabled and caching is turned on
config.consider_all_requests_local = false # changed from true
config.action_controller.perform_caching = true # changed from false
And then after restarting passenger, rails showed me the error w/ stacktrace. Turns out I was forgetting to precompile the asset pipeline!
Things to check
1) Are you sure you are running in production environment?
Check to see if any entries are in the development.log file
2) Set up your app to email you when a 500 error occurs with a full stack trace. I use the Exception Notifier gem but there are plenty of other solutions for this.
3) When checking your app in the console are you sure you are starting the console in production mode? It is possible that the app is not starting up at all and you just forgot to set the production param thereby thinking that the app runs fine when it doesn't.
4) Are you getting an nginx 500 error or the Rails 500 error? If nginx then it is likely that your app is not starting at all and highly unlikely that you will get any rails error in your log file. The assets are static files and navigating to them proves nothing other than that they exist.
5) Are you sure you are checking the right folder on the server? Sounds really stupid but capistrano could be deploying the app to a folder that is different to the folder that nginx is looking for for your app so double check both the folder capistrano is deploying to and the folder that nginx is looking for are the same.
Just a suggestion, I would use puma rather than passenger. It's awesome with nginx.
My problem is passenger's log file (error.log) has nothing. Then it's a rotation log issue. Run
passenger-config reopen-logs
solved my problem. More.
Have you tried running in development mode to see if the error reports itself?

No log messages in production.log

I wrote a demo HelloWorld Rails app and tested it with WEBrick (it doesn't even use a DB, it's just a controller which prints "hello world"). Then I tried to deploy it to a local Apache powered with Passenger. In fact this test is just to get Passenger working (it's my first deploy on Apache). Now I'm not even sure that Passenger works, but I don't get any error on the Apache side.
When I fire http://rails.test/ the browser shows the Rails 500 error page - so I assume that Passenger works. I want to investigate the logs, but it happens that production.log is empty! I don't think it's a permission problem, because if I delete the file, it is recreated when I reload the page. I tried to change the log level in conf/environments/production.rb, tried to manually write to log file with Rails console production and
Rails.logger.error('asdf')
it returns true but nothing gets written to production.log. The path (obtained per Rails.logger.inspect) is correct, and I remark that the file is recreated if I manually remove it. How can I know what's going on?
(I already checked the Apache logs, plus I set the highest debug level for Passenger but it seems a Rails problem, so is not logged by the server)
Assuming you're running Rails 3.2.1, this is a bug. It was patched in 3.2.2.
If you can't upgrade to 3.2.2 for any reason, this comment on GitHub has a workaround:
# config/initializers/patch_rails_production_logging.rb
Rails.logger.instance_variable_get(:#logger).instance_variable_get(:#log_dest).sync = true if Rails.logger
Setting this works on Rails 3.2.11:
Rails.logger = ActiveSupport::BufferedLogger.new(Rails.root.join("log","production.log"))

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