2.0.2 memory footprint

http://izumi.plan99.net/blog/index.php/2008/03/19/memory-usage-comparison-rails-126-vs-202/
The article above says, if I did understand it correctly, that the 2.0.2
memory footprint should be smaller than that of 1.2.6.

After migrating my web app to 2.0.2 I found that the memory footprint
has actually increased by circa 2Mb.

So who is right, the article above or my web app?
Am I doing something wrong?

Thank you in Advance,
Emanuele.

http://izumi.plan99.net/blog/index.php/2008/03/19/memory-usage-comparison-rails-126-vs-202/
The article above says, if I did understand it correctly, that the
2.0.2
memory footprint should be smaller than that of 1.2.6.

After migrating my web app to 2.0.2 I found that the memory footprint
has actually increased by circa 2Mb.

By memory footprint, which of the 4 different measures of memory usage
did you look at ?

Fred

Frederick Cheung wrote:

http://izumi.plan99.net/blog/index.php/2008/03/19/memory-usage-comparison-rails-126-vs-202/
The article above says, if I did understand it correctly, that the
2.0.2
memory footprint should be smaller than that of 1.2.6.

After migrating my web app to 2.0.2 I found that the memory
footprint
has actually increased by circa 2Mb.

By memory footprint, which of the 4 different measures of memory
usage
did you look at ?

Fred

RSS

The blog article doesn't mention any reduction in RSS and also says
why it's not particularly useful a measurement (in this context).

Fred

Frederick Cheung wrote:

After migrating my web app to 2.0.2 I found that the memory
footprint
has actually increased by circa 2Mb.

By memory footprint, which of the 4 different measures of memory
usage
did you look at ?

Fred

RSS

The blog article doesn't mention any reduction in RSS and also says
why it's not particularly useful a measurement (in this context).

Fred

I see. I hoped for a reduction in memory usage by rails...

Talking about memory maybe you might give me some light on an issue
thats bothering me since long:

It seems that the nearest the memory fotprint gets to 30Mb or around
with my web apps the sooner it hysterically jumps to 34-37Mb.
I noticed so because with lighttpd which has a lower footprint my app
grows slowly depending on classes loaded through the requests till it
gets to around 30Mb than it jumps to 34-37. With mongrel that has a
bigger footprint it takes less to trigger the memory jump. With mongrel
and 2.0.2 it happens almost as soon as with the first request.

Any clue?

Frederick Cheung wrote:

After migrating my web app to 2.0.2 I found that the memory
footprint
has actually increased by circa 2Mb.

By memory footprint, which of the 4 different measures of memory
usage
did you look at ?

Fred

RSS

The blog article doesn't mention any reduction in RSS and also says
why it's not particularly useful a measurement (in this context).

Fred

I see. I hoped for a reduction in memory usage by rails...

I'm no expert, but what he's saying is that because of the way ruby
allocates memory, it's not always obvious how the 2 correlate.

Talking about memory maybe you might give me some light on an issue
thats bothering me since long:

It seems that the nearest the memory fotprint gets to 30Mb or around
with my web apps the sooner it hysterically jumps to 34-37Mb.
I noticed so because with lighttpd which has a lower footprint my app
grows slowly depending on classes loaded through the requests till it
gets to around 30Mb than it jumps to 34-37. With mongrel that has a
bigger footprint it takes less to trigger the memory jump. With
mongrel
and 2.0.2 it happens almost as soon as with the first request.

Any clue?

Not the slightest.

Fred

Ruby allocated memory in 8Mb chunks. So when your process gets close to 16Mb it will jump to 24Mb and when it gets close to 32Mb it will jump to ~40 and so on.

Cheers-

- Ezra Zygmuntowicz
-- Founder & Software Architect
-- ezra@engineyard.com
-- EngineYard.com

Thank you very much.
I thought it was a memory leak, but couldn't find any.

Any clues on how to change this behaviour?

http://www.ruby-forum.com/topic/149847#new

I solved the memory spike problem as you can read here:
http://www.ruby-forum.com/topic/149847