# Refactoring cpu-intensive actions

**URL:** <https://www.ruby-forum.com/t/refactoring-cpu-intensive-actions/125753>\
**Category:** Rails\
**Created:** [January 11, 2008, 6:59pm UTC](https://www.ruby-forum.com/t/refactoring-cpu-intensive-actions/125753 "2008-01-11T18:59:30Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Gammons](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/eb8c5e/32.png) [@Gammons](https://www.ruby-forum.com/u/Gammons)\
**Post date:** [January 11, 2008, 6:59pm UTC](https://www.ruby-forum.com/t/refactoring-cpu-intensive-actions/125753/1 "2008-01-11T18:59:30Z")

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Hey Guys,

I wanted to get some general opinions about a particularly cpu-  
intensive action I have that generates XML to be fed into a flash-  
based graph.

The data collected for the graph is per-user and is already cached as  
much as possible. We use a combination of cache\_fu, a 5 minute ttl  
fragment cache for the action itself, and model method caching  
(partially cache\_fu, partially homegrown).

The problem is that when there is a cache miss and the user has a  
large amount of data to process, ruby just chugs for a long time…  
possibly 30 seconds or even longer (until a mongrel timeout finally  
occurs.), so this action is obviously ripe for a refactor.

I decided to replicate the same action as a java class, and achieved a  
speedup of roughly 6-7x (5-6 seconds to generate the xml needed as  
opposed to about 35 seconds for ruby).

Another idea I had was to create a mysql stored procedure to gather  
all the data needed, which can then be synthesized into xml on the  
ruby side (this may be preferable since I won’t have to introduce java  
into our production mix.

I welcome any thoughts/ideas!

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**Author:** ![Gammons](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/eb8c5e/32.png) [@Gammons](https://www.ruby-forum.com/u/Gammons)\
**Post date:** [January 11, 2008, 7:06pm UTC](https://www.ruby-forum.com/t/refactoring-cpu-intensive-actions/125753/2 "2008-01-11T19:06:32Z")

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On 11 Jan 2008, at 17:58, Gammons wrote:

> (partially cache\_fu, partially homegrown).  
> Another idea I had was to create a mysql stored procedure to gather  
> all the data needed, which can then be synthesized into xml on the  
> ruby side (this may be preferable since I won’t have to introduce java  
> into our production mix.

Other approaches you might try include RubyInline/a ruby extension  
(especially if the bottleneck is actually quite a small amount of code).  
A somewhat orthogonal approach is to use something like backgroundrb  
to decouple the processing from the http requests, so that you don’t  
hog mongrels for too long.

Fred.

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**Author:** ![Gammons](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/eb8c5e/32.png) [@Gammons](https://www.ruby-forum.com/u/Gammons)\
**Post date:** [January 11, 2008, 7:13pm UTC](https://www.ruby-forum.com/t/refactoring-cpu-intensive-actions/125753/3 "2008-01-11T19:13:35Z")

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Thanks fred, I actually have never considered using RubyInline… I  
will check it out!

Unfortunately I can’t use BackgroundRB as the data needs to be  
generated in “real time”. As a side, we have experimented with  
backgroundrb and concluded it’s a pretty poor offering. We found that  
using Amazon SQS + ActiveMessaging + separate server is a much better  
approach to backgrounding intensive tasks that don’t need to be  
completed in real time. But that’s another topic!

Thanks again,  
Grant

On Jan 11, 1:06 pm, Frederick C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)