# Mongrel and memory usage **URL:** \ **Category:** Mongrel\ **Created:** [November 5, 2007, 11:21am UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244 "2007-11-05T11:21:55Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 6, 2007, 1:57pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/21 "2007-11-06T13:57:36Z")
On 11/6/07, Pete DeLaurentis [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Does Mongrel need to be multi-threaded at all if you’re working with > Rails applications? No. > If all 8 mongrels are busy, I believe Lighty retries the cycle a few > times. So, who needs threads? I’m guessing this is a naive > question, but I’d appreciate it if you’d set me straight. evented\_mongrel still queues the request, but it does so without creating any threads, so there isn’t the thread related RAM growth. > Once I get a breather in my release schedule, I plan to look at a > switch to evented mongrel. Performance benchmarks + community > feedback looks very good. But I still need to get a better grasp on > how it works + the differences from standard mongrel. My intention is that switching to evented\_mongrel or swiftiplied\_mongrel is transparent from the perspective of the application (or whatever is running inside a mongrel handler). Kirk H. ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 6, 2007, 12:08pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/22 "2007-11-06T12:08:00Z")
At 09:17 AM 11/5/2007, you wrote: > Otherwise, can you start a test instance of your application, and then > test it to see if there are certain actions which cause the memory > growth. That would help you pinpoint where the likely problems are. > Just use ab or httperf to send a large number of requests to specific > urls in your app, and see how ram usage changes as you do that. > > Kirk H. Thanks Kirk - I guess I’m totally OT at this point, but I hadn’t heard about this bug before. From your description this is a specific problem to the underlying C code implementing shift, which is not found in related functions? So “array.slice!(0)” would be identical in function to shift but not contain this leak? Thanks again, Steve ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 6, 2007, 3:55pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/23 "2007-11-06T15:55:15Z")
On 11/6/07, Bob H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > It isn’t fixed in the ruby that ships with Leopard: > 1.8.6 (2007-06-07 patchlevel 36) [universal-darwin9.0] Ugh. IIRC I checked it with the patch release after 36, and it was fixed there. > end > Note that this just _mostly_ fixes things. You still end up with > array elements in memory carrying around Qnils, but most of the time > that’s good enough. Kirk H. ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 6, 2007, 4:06pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/24 "2007-11-06T16:06:22Z")
Why not build from source: ruby 1.8.6 (2007-09-23 patchlevel 110) [i686-darwin8.10.1] ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 6, 2007, 3:36pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/25 "2007-11-06T15:36:30Z")
Hi, On 5-Nov-07, at 1:38 PM, Kirk H. wrote: > Yeah. It looked to me like whoever wrote the original array.c code > just forgot something when writing the code, because it’s just #shift > that has the problem. > > This bug was fixed, but not until 1.8.6. I know it is fixed as of at > least the last couple of patch releases. I am unsure if it was fixed > in the original 1.8.6 release, however. It isn’t fixed in the ruby that ships with Leopard: 1.8.6 (2007-06-07 patchlevel 36) [universal-darwin9.0] This hack will fix things. class Array alias :naughty\_shift :shift def shift result = self.first self[0] = nil # This is the ‘magic’ self.naughty\_shift result end end > > Kirk H. > > * * * > > Mongrel-users mailing list > removed\_email\_address@domain.invalid > [http://rubyforge.org/mailman/listinfo/mongrel-users](http://rubyforge.org/mailman/listinfo/mongrel-users) * * * Bob H. – tumblelog at [http://www.recursive.ca/so/](http://www.recursive.ca/so/) Recursive Design Inc. – weblog at [http://www.recursive.ca/hutch](http://www.recursive.ca/hutch) [http://www.recursive.ca/](http://www.recursive.ca/) – works on [http://www.raconteur.info/cms-for-static-content/home/](http://www.raconteur.info/cms-for-static-content/home/) ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 7, 2007, 5:51pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/26 "2007-11-07T17:51:07Z")
On Mon, 5 Nov 2007 09:55:34 -0600 “Alexey V.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > But Ruby processes never release memory back to the operating system. > So, the fact that its RSS never goes down is normal. > > In normal circumstances, Mongrel should grow up to some point around > 60-120 Mb and stay there. 300 Mb and growing is a sure sign you have a > memory leak somewhere. Ehem, s/Mongrel/Ruby/g on the above. – Zed A. Shaw - Hate: [http://savingtheinternetwithhate.com/](http://savingtheinternetwithhate.com/) - Good: [http://www.zedshaw.com/](http://www.zedshaw.com/) - Evil: [http://yearofevil.com/](http://yearofevil.com/) ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 7, 2007, 5:56pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/27 "2007-11-07T17:56:58Z")
On Tue, 6 Nov 2007 14:34:25 +1100 Dave C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > [Peak Obsession](http://api.rubyonrails.com/classes/ActionController/Streaming.html#M000093) > > Is this a bug in send\_file? You souldn’t use send\_file at all really, because this streams the full file into a StringIO so that mongrel can then send the StringIO outside the rails lock, and because rails is inconsistent in how it sends headers and the body. You should be using either x-sendfile or simply redirect to the real image. If you need to auth the images then check out some of the auth-before-redirect modules available for various web servers. – Zed A. Shaw - Hate: [http://savingtheinternetwithhate.com/](http://savingtheinternetwithhate.com/) - Good: [http://www.zedshaw.com/](http://www.zedshaw.com/) - Evil: [http://yearofevil.com/](http://yearofevil.com/) ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 7, 2007, 10:54pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/28 "2007-11-07T22:54:05Z")
> If you need to auth the images then check out some of the auth-before-redirect modules available for various web servers. I think Danga’s Perlbal was made for just this purpose. Evan ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [November 7, 2007, 5:54pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/29 "2007-11-07T17:54:02Z")
On Mon, 5 Nov 2007 17:06:01 +0100 “Thomas B.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hello Kirk, > > Thanks for your answer. > I’m using ruby 1.8.5 (2006-08-25) [i486-linux]. > The Rails app uses those plugins : > > - acts\_as\_taggable\_on\_steroids > - attachment\_fu > - exception\_notification > - localization Hmm, I seem to see this problem quite a lot with attachment\_fu installations. Just a hunch. – Zed A. Shaw - Hate: [http://savingtheinternetwithhate.com/](http://savingtheinternetwithhate.com/) - Good: [http://www.zedshaw.com/](http://www.zedshaw.com/) - Evil: [http://yearofevil.com/](http://yearofevil.com/) ---
**Author:** ![tbaustert](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ecae2f/32.png) [@tbaustert](https://www.ruby-forum.com/u/tbaustert)\ **Post date:** [December 7, 2007, 2:54pm UTC](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244/30 "2007-12-07T14:54:37Z")
Hello, I just wanted to tell the list that I’ve spent some time to optimize my code a little, I’ve reworked some SQL queries, removed some part of Rails I wasn’t using … Now, both mongrel processes are stable at 150Mb each. T. [Previous page](https://www.ruby-forum.com/t/mongrel-and-memory-usage/119244.md?page=1)