Doesn't work with Passenger

[pranas]

Hi,

I can't get girl_friday working with Passenger. I've bare Rails app https://github.com/Pranas/girl_friday_test . I'm using Ruby 1.9.3-p125, Rails 3.2 and Passenger 3.0.11. Steps to reproduce:

1. gem install passenger
2. passenger start
3. hit http://localhost:3000

It should print 'ok' and touch /tmp/test123 file.

[jc00ke]

Passenger isn't supported because it's based on an event loop, not threads like unicorn or puma.

[jrochkind]

Hi, is this a revision of the answer in #38, which suggested Passenger would work just fine so long as you have it do conservative spawning, and/or create queues lazily?

Which is correct, Passenger can work with a few simple accomodations, or Passenger is right out?

[jc00ke]

Passenger is not supported as a viable app server. If you figure it out, please let us know & we can update the docs. I suppose it might be possible to get Passenger & girl_friday to play nicely together, but it may not be easy.

[jrochkind]

Thanks. Is there any 'elevator speech' overview of what the problems
are?

I basically have my own handmade custom background thread solution
that I use in a Rails app, which seems to deploy just fine under
Passenger. I was investigating switching to girl_friday. I wonder
what's going on with passenger/girl_friday interaction that hasn't
seemed to have bitten my homegrown threaded solution.

[jc00ke]

The root is that running threads in an evented server can be trouble. Not saying you can't do it, we just say we don't support it :wink:

[jrochkind]

Hmm, I have no idea what that means. I guess if I get the time/ motivation I'll try it and see what happens. Although I don't like the
idea of running something where the people who DO understand it tell
me there might be problems, that I clearly don't understand well
enough to recognize or debug if they happen, or predict when they might!

I have learned more than I ever wanted to know about ruby, threading,
Rails and ActiveRecord, in my current efforts to write my own threaded
handling in a rails app from scratch, but haven't (yet cross fingers)
run into any problems with passenger doing anything problematic.

On Mar 22, 2012, at 6:53 PM, Jesse Cooke wrote:

The root is that running threads in an evented server can be
trouble. Not saying you can't do it, we just say we don't support
it :wink:

---

Reply to this email directly or view it on GitHub: https://github.com/mperham/girl_friday/issues/49#issuecomment-4650187

[jrochkind]

Huh, googling around to figure out exactly what 'evented' means in
this case for Passenger, I find an interview with Passenger developers
claiming that Passenger right now does not use an 'an evented I/O
architecture' (although future versions will), but uses a
'multithreaded I/O architecture'. I guess I'm just out of my league,
I'm lost already. http://www.infoq.com/news/2012/02/ruby-eee-eol

On Mar 22, 2012, at 6:53 PM, Jesse Cooke wrote:

The root is that running threads in an evented server can be
trouble. Not saying you can't do it, we just say we don't support
it :wink:

---

Reply to this email directly or view it on GitHub: https://github.com/mperham/girl_friday/issues/49#issuecomment-4650187

[jrochkind]

I wonder if it's not 'evented' that's been a problem, but just the
need to make sure you re-fill your thread pool after Passenger forks a
new copy of an app? http://www.modrails.com/documentation/Users%20guide%20Apache.html#_smart_spawning_gotcha_2_the_need_to_revive_threads

I dunno, anyways, I guess if I have time and motivation i'll try it
and see.

[mperham]

Passenger and Unicorn are not evented. thin is evented.

Passenger is supported, you just need to create your girl_friday queues within Passenger's starting_worker_process block. Unicorn has the same issue: read more in #47.

[jrochkind]

Thanks! This seems to come up and get conflicting answers in the
issues, perhaps note in initial README what webservers are supported,
and special instructions for passenger?

Note though, that I did find that Passenger is looking at switching
to be evented in the next release, so, there's that. I still don't
understand exactly what issues this causes for threads, but sounds
like it could be a problem.