I'm writing a web application to monitor a furniture factory production flow. It has thousand of data to handle. So far, I run RoR on Mongrel + MySQL and it's really really slow (2-4min for some views). When I look at RoR logs, it seems that database queries aren't slow (0-10ms).
Is RoR slow when it converts database data to object ? Is Mongrel slow ?
Edit: First thing: I was in dev. env. In production environment, the slowest view takes 2min (which would turn down to less than 1min on a good computer, mine is 5 years old). With ruby-prof and a bit of common sense, I've found out which methods were slowing down the application. The problem is that single sql queries are called in loops on larges datasets:
ofs = Ofkb.find_by_sql ["..some large sql query..."]
for of in ofs # About 700-1000 elements
ops = Operation.find(..the single query..)
etc.
end
Here are ruby-prof results on those methods:
%self total self wait child calls name
32.19 97.91 97.91 0.00 0.00 55 IO#gets (ruby_runtime:0}
28.31 86.39 86.08 0.00 0.32 32128 Mysql#query (ruby_runtime:0}
6.14 18.66 18.66 0.00 0.00 12432 IO#write (ruby_runtime:0}
0.80 2.53 2.42 0.00 0.11 32122 Mysql::Result#each_hash (ruby_runtime:0}
Problem is: I can't really avoid those single queries. I've got thousand of events from which I have to compute complex data. Right now I'm using memcached on those methods which is OK unless your the first to request the page.