# Ruby on Rails performance / Why is Mongrel popular? **URL:** \ **Category:** Rails\ **Created:** [March 12, 2007, 10:59am UTC](https://www.ruby-forum.com/t/ruby-on-rails-performance-why-is-mongrel-popular/88521 "2007-03-12T10:59:03Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Shaoxia](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/5fc32e/32.png) [@Shaoxia](https://www.ruby-forum.com/u/Shaoxia)\ **Post date:** [March 12, 2007, 10:59am UTC](https://www.ruby-forum.com/t/ruby-on-rails-performance-why-is-mongrel-popular/88521/1 "2007-03-12T10:59:03Z")
I’ve been a satisfied Ruby on Rails developer for quite some time now. Recently I’m considering using Rails again for a new website. But this website has _many_ visitors - 40k unique visitors per day (and about 200k page loads per day) - so I’m worried about performance and memory usage. I wrote a little test application - it has one controller, ‘Person’, and one method, ‘test’. The method ‘test’ is not implemented, I only put a file ‘test.rhtml’ in the ‘views/person’ folder. test.rhtml contains the text “hello world”. I started Rails as follows: ./script/server &\>/dev/null (output is redirected to /dev/null so that I won’t be testing the performance of my terminal emulator) Rails uses lighttpd as web server. I ran httperf as follows: httperf --num-conn=100 --server=localhost --port=3000 --uri=/person/ test --timeout=5 --hog And the result is alarmingly low: the request rate is only 15.5 per second! For comparison, I also wrote a ‘hello world’ PHP script (test.php) - the script doesn’t contain any PHP calls, only the text ‘hello world’: httperf --num-conn=100 --server=localhost --port=80 --uri=/test.php – timeout=5 --hog … Request rate: 1018.3 req/s (1.0 ms/req) It seems rails is about 100 times slower. I can load balance the website, but that costs money - lots of money. I don’t have that much money. Am I doing something wrong, or is Rails really that slow? I’ve also tried Mongrel instead of lighttpd, but there was no performance increase. Speaking of Mongrel, why is it so popular? Why is everybody moving away from lighttpd and toward Mongrel? - Last time I checked, Mongrel can only process one request at the same time. So suppose a Rails requests needs 5 seconds to complete, then all other clients will have to wait 5 seconds as well. Lighttpd seems to spawn a new Rails process if the current one hasn’t finished. - I also read that people uses Apache (or lighttpd) as load balancer, and proxies requests to several Mongrel instances. But doesn’t that waste memory like mad? Each Mongrel process seems to need 31 MB at startup (and this is for an empty ‘hello world’ Rails app). If you have n Mongrel processes then you need at least n\*31 MB of memory! Almost no memory is shared because the Ruby parse tree is not shared between Ruby instances, unlike native shared libraries. Can someone provide me with the answer to these questions? ---
**Author:** ![Shaoxia](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/5fc32e/32.png) [@Shaoxia](https://www.ruby-forum.com/u/Shaoxia)\ **Post date:** [March 12, 2007, 11:35am UTC](https://www.ruby-forum.com/t/ruby-on-rails-performance-why-is-mongrel-popular/88521/2 "2007-03-12T11:35:09Z")
Shaoxia wrote: > For comparison, I also wrote a ‘hello world’ PHP script (test.php) - > the script doesn’t contain any PHP calls, only the text ‘hello world’: > httperf --num-conn=100 --server=localhost --port=80 --uri=/test.php – > timeout=5 --hog > … > Request rate: 1018.3 req/s (1.0 ms/req) > > It seems rails is about 100 times slower. I can load balance the > website, but that costs money - lots of money. I don’t have that much > money. Am I doing something wrong, or is Rails really that slow? You are running in development mode. Try production mode. Also 200k page views spread over a 12 hour period is 4.6 page views per second. That’s hardly that many page views per second. On my 2.0 GHz Athlon 64 (single-core) Linux box I get 15.6 req/s with Mongrel in development mode and 103.7 req/s in production mode with a test “hello world” RHTML file (no embedded Ruby) using your above httperf command. > I’ve also tried Mongrel instead of lighttpd, but there was no > performance increase. Speaking of Mongrel, why is it so popular? Why > is everybody moving away from lighttpd and toward Mongrel? People are saying that Mongrel is more reliable and it’s easier to setup in a load-balanced cluster with Apache 2.2 with mod\_proxy\_balancer. I never did the FastCGI/lighttpd setup so I can’t comment on that personally but I’ve been using Mongrel on my low traffic site with no issues at all. > between Ruby instances, unlike native shared libraries. > > Can someone provide me with the answer to these questions? Well “waste memory like mad” is a subjective thing but yes if you run a large cluster of load-balanced Mongrel processes behind Apache 2.2 mod\_proxy\_balancer you will use up a good chunk of memory. It’s not clear that with 200K page views a day you need to do that. – Michael W. ---
**Author:** ![Shaoxia](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/5fc32e/32.png) [@Shaoxia](https://www.ruby-forum.com/u/Shaoxia)\ **Post date:** [March 12, 2007, 11:37am UTC](https://www.ruby-forum.com/t/ruby-on-rails-performance-why-is-mongrel-popular/88521/3 "2007-03-12T11:37:10Z")
> website, but that costs money - lots of money. I don’t have that much > money. Am I doing something wrong, or is Rails really that slow? > Rails has a built-in caching mechanism that should help. Have a look > at the caches\_page method. You can also arrange to have static content served directly through Apache without touching Rails at all. > - Last time I checked, Mongrel can only process one request at the > same time. So suppose a Rails requests needs 5 seconds to complete, > That’s right. I’m using mongrel\_cluster+monit with four mongrels - but > I don’t get 200k hits a day. > then all other clients will have to wait 5 seconds as well. Lighttpd > seems to spawn a new Rails process if the current one hasn’t finished. > Both Lighttpd and Apache can be configured to spawn new processes as > needed, instead of keeping them around. This means you eat the > significant startup overhead at request time, though. Even back when I > was using Apache+Fastcgi I preferred to have all the dispatch.fcgi > processes start with the server. > Can someone provide me with the answer to these questions? > No magic bullet, I’m afraid. Caching, performance tuning, and a lot of > free memory… Gwyn.