Trouble With Rails and Ruby 1.8.5

Thursday, 28 December 2006

I recently had to write and deploy a custom Rails app for a customer. When it was time for me to install the dedicated server, I looked for which Ruby version to install. I naturally went for the latest stable version of Ruby: 1.8.5. Unfortunalety I quickly ran through serious trouble with this version and Rails.

Mongrel for instance. I didn’t notice on their web site that asking for 1.8.4 was an absolute requirement. Just after a few hours running the web site in production, Mongrel just crashed and segfault! Wow, last time I saw a segfault was years ago. I had to fallback quickly to Webrick on the production server so I could downgrade Ruby to 1.8.4 as quickly as possible.

The stack trace shown me that a call to Thread.new in Mongrel’s code caused the segfault. Mongrel is using native code but the crash didn’t seem to have occured in that part. So if it’s into the Ruby VM code, that’s more annoying.

I read recent posts talking about issues with current implementation of Ruby. People know that the current VM is complex and difficult to hack. Apparently alternative implementations over Java/.NET and native implementation are on going. That’s a very hot topic and I hope something will emerge quickly.

I’ve been working with Java for 5 years and it’s stability is awesome. Crashes are rare and memory management works great. I hope I could say that to Ruby. We all know that’s not easy to sell a new technology in the enterprise world and that only one crash could easily let people think that’s not mature and ruin all your efforts.

For the moment, I would strongly advise to stick with Ruby 1.8.4 until further investigations are done. If somebody know anything about the issue, please let me know.

UPDATE (Feb 26th, 2007): The problem is now fixed! I finally found out what was breaking all my Ruby installation: GCC 4.0, preinstalled on Ubuntu 6.06. I recompiled Ruby and all gems with GCC 3.3 and now everything works perflectly: no more crash and no more memory leaks. It’s actually weird how many things GCC 4.0 breaks… I’m happy the story is over.

Posted in Development, Ruby on Rails

Comments

UPDATE: I recently had a crash with Ruby 1.8.4. Apparently, it took much more time than with Ruby 1.8.5 but I really don’t know what’s happening. Maybe I should restart the Mongrel process once a day.

Frederic Brunel2 January 07 at 2:21 am
UPDATE: I recently had a crash with Ruby 1.8.4. Apparently, it took much more time than with Ruby 1.8.5 but I really don’t know what’s happening. Maybe I should restart the Mongrel process once a day.

Fred Brunel1 January 07 at 7:21 pm
Just stumbled across this post, make sure you have fastthread installed as a gem, that should correct your issues.

sudo gem install fastthread

Current version is 0.6.1 i believe

Michael D'Auria5 January 07 at 12:46 am
Just stumbled across this post, make sure you have fastthread installed as a gem, that should correct your issues.

sudo gem install fastthread

Current version is 0.6.1 i believe

Michael D'Auria4 January 07 at 5:46 pm
Also, are you rotating out the production.log file? If so you are going to have to restart your Mongrels

Michael D'Auria5 January 07 at 12:50 am
Also, are you rotating out the production.log file? If so you are going to have to restart your Mongrels

Michael D'Auria4 January 07 at 5:50 pm
Hi Michael,

Thanks a lot for your help, I’ll give it a try as soon as possible. If it actually fix the issue, I’m just wondering why this is not part of Ruby core or a mandatory dependency with Mongrel’s gem.

By the way, do you know if Ruby has to be compiled with pthread support (thing that I’ve done) because it’s not enabled by default.

Concerning the log file, I’m not rotating it at the moment…

Frederic Brunel5 January 07 at 1:52 am
Hi Michael,

Thanks a lot for your help, I’ll give it a try as soon as possible. If it actually fix the issue, I’m just wondering why this is not part of Ruby core or a mandatory dependency with Mongrel’s gem.

By the way, do you know if Ruby has to be compiled with pthread support (thing that I’ve done) because it’s not enabled by default.

Concerning the log file, I’m not rotating it at the moment…

Fred Brunel4 January 07 at 6:52 pm
I honestly never change any of the default options. Just the usual configure, make && make install.

That’s interesting that you are seeing this issue and are not rotating logs. Perhaps you should email the Mongrel mailing list and Zed will chime in.

Michael D'Auria8 January 07 at 10:40 pm
I honestly never change any of the default options. Just the usual configure, make && make install.

That’s interesting that you are seeing this issue and are not rotating logs. Perhaps you should email the Mongrel mailing list and Zed will chime in.

Michael D'Auria8 January 07 at 3:40 pm
Hi Michael,

That’s what I though concerning the installation procedure… Generally default settings are just fine.

I followed your advices and I managed to get more stability but I had to downgrade lots of software…

I’m now running with Ruby 1.8.4 + fastthread + Mongrel 0.3.13.3. I had the issue with Mongrel 0.3.13.4 and 1.0.

Actually, the configuration I use is also the choice of one my hosting provider (http://a2hosting.com) where I also run some Rails apps…

I’ll try the Mongrel mailing list as you suggested.

Thanks for your help.

Frederic Brunel9 January 07 at 2:44 pm
Hi Michael,

That’s what I though concerning the installation procedure… Generally default settings are just fine.

I followed your advices and I managed to get more stability but I had to downgrade lots of software…

I’m now running with Ruby 1.8.4 + fastthread + Mongrel 0.3.13.3. I had the issue with Mongrel 0.3.13.4 and 1.0.

Actually, the configuration I use is also the choice of one my hosting provider (http://a2hosting.com) where I also run some Rails apps…

I’ll try the Mongrel mailing list as you suggested.

Thanks for your help.

Fred Brunel9 January 07 at 7:44 am
I also have memory leak problems (using Mongrel or Webrick). I have some difficulties to investigate the issue.

I found some introspection code that dumps objects state but it’s not easy to find out.

I you have suggestions.

Frederic Brunel9 January 07 at 2:49 pm
I also have memory leak problems (using Mongrel or Webrick). I have some difficulties to investigate the issue.

I found some introspection code that dumps objects state but it’s not easy to find out.

I you have suggestions.

Fred Brunel9 January 07 at 7:49 am
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