Single mongrel -- ok for low traffic?

Media Temple is offering what seems like an interesting offering with
their Grid Server, claimed to be much superior to typical shared
servers, for $20/month. You can get a “Rails Container” with 64M as
part of this price, or with 256M for another $25/month. So its
$45/month for a 256M rails setup. You can have up to 100 domains and
multiple rails apps.

However… they allow only one Mongrel instance per container.
Everything I see about deploying on Mongrel talks about using multiple
instances with mongrel_cluster. MT says they may offer that in the
future.

My question: just how bad is it to run a rails app with a single
Mongrel instance? If it gets, say, 1000 hits per day, is that really
much of an issue?

thanks,

Michael

Michael S. wrote:

future.

My question: just how bad is it to run a rails app with a single
Mongrel instance? If it gets, say, 1000 hits per day, is that really
much of an issue?

Others will be able to give you the benefit of much more experience, but
this seems very strange to me. Rails is expensive on memory precisely
because you need a whole Ruby/Rails process per concurrent request. If
you are limited to one Mongrel, it doesn’t make sense to have large
amounts of RAM, many domains, or multiple apps.

For a low-volume app why not start with DreamHost, using one of their
first-year discount codes? You could get your first year for about the
price of one month at MediaTemple, and you would get more than one
FastCGI process. (By the way Mongrel support is one of the future
possibilities DreamHost users can vote for, and I have voted for it.)

regards

Justin

P.S. Sorry for the delay in replying - your message circulated in the
ether (with a bunch of others) for nearly two weeks before reaching me.

future.

My question: just how bad is it to run a rails app with a single
Mongrel instance? If it gets, say, 1000 hits per day, is that really
much of an issue?

Let’s assume that it’s 1000 pages per day since if it’s hits, most of
that is going to be images/css/javascript and served up by apache (if
they’ve configured it right).

Even so… 1000 pages/day / 24 hours/day / 60 minutes/hour = .69
pages/minute.

A single mongrel can easily do that and should be able to handle
anywhere from 20-60 requests per second depending on what your’e asking
it
to do.

And this assumes that you aren’t cashing anything. For a low traffic
site (personal, blog, etc.) it would be fine. It would be nice to know
that if you got really popular you could easily expand to multiple
mongrels though…

I’d say if everything else seems good, go for it.

-philip

Thanks for the comments. I got nervous about the Media Temple grid
server after reading about lots of downtime people were experiencing,
and I concluded it wasn’t quite mature enough. I decided to spring for
a BantamVPS at Rails Machine, which is about twice the cost but should
be very robust.

Just wondering, what’s the scenario with file uploads and mongrel. If
the site allows users to upload files, won’t the mongrel process be
busy while the file is getting uploaded ?

to do.

And this assumes that you aren’t cashing anything. For a low traffic
site (personal, blog, etc.) it would be fine. It would be nice to know
that if you got really popular you could easily expand to multiple
mongrels though…

I’d say if everything else seems good, go for it.

-philip


rm -rf / 2>/dev/null - http://null.in

Dont judge those who try and fail, judge those who fail to try…

On Dec 3, 2006, at 4:20 PM, Pratik wrote:

site (personal, blog, etc.) it would be fine. It would be nice to
know
that if you got really popular you could easily expand to multiple
mongrels though…

I’d say if everything else seems good, go for it.

-philip

No, Mongrel won’t be busy during the upload. It handles the upload in
a separate thread and can manage many other connections during the
upload. However, once the upload completes, Mongrel will pass the
file on to Rails which will require it get re-parsed by cgi.rb which
could take quite a long time (several seconds per 10MB).

In summary, Mongrel is nicely threaded and will handle many things
simultaneously. When it comes to communicating with Rails, everything
has to go through a Mutex which locks Mongrel out from doing other work.

cr

(By the way Mongrel support is one of the future
possibilities DreamHost users can vote for, and I have voted for it.)

Here’s the voting link, if other dreamhost customers would like to vote:
https://panel.dreamhost.com/index.cgi?tree=home.sugg&category=Software%20Installations&search=mongrel

Chris

Michael S. wrote:

Thanks for the comments. I got nervous about the Media Temple grid
server after reading about lots of downtime people were experiencing,
and I concluded it wasn’t quite mature enough. I decided to spring for
a BantamVPS at Rails Machine, which is about twice the cost but should
be very robust.

Looking around after I had replied to you, I got the impression that
Media Temple had built up a good reputation before they went for this
“grid” thing, but that the grid has a lot of problems. I looked at the
technical guidance on their site and was unimpressed. I’m sure you’ll be
happier with Rails Machine.

regards

Justin