Use Monit with Rails, not God

http://blog.bradgessler.com/use-monit-with-rails-not-god#

by bradgessler • 17 years ago

22 34 17 years ago

blog.bradgessler.com

Haven't all the cool kids moved on to Phusion Passenger? Is there still a compelling reason to play around with mongrel/thin etc clusters?

bradgessler4• 17 years ago

Yeah, that's the next trend. There are still quite a few people though stuck with mongrels/things and are still using God.

For our company we're stuck with thins because of a very specific way we're launching our application. Phusion doesn't have everything we need (yet).

charlesju2• 17 years ago

EY doesn't support Passenger for their big clients yet. So all the big Rails sites through EY use nginx + mongrels.

However, EY does use monit.

FooBarWidget• 17 years ago

EY is now offering Phusion Passenger for Nginx to their clients.

plinkplonk3• 17 years ago

"Ruby leaks. God is written in ruby. If you run God long enough, it will run out of memory and stop working properly. In all fairness, this is not Tom Presten-Warners fault. He spent a lot of time trying to minimize the leakage in God but its simply not possible in Ruby. Monit was written properly in C meaning it won't leak like a long-running Ruby application."

This is absolutely hilarious! A process monitor leaks memory and crashes the server. Words fail me!

EDIT: Rub my eyes and read again. Ruby leaks memory? The language (interpreter ? VM? ) leaks memory? That can't be right? He must have meant the application (God) leaks memory (perhaps by holding onto objects and not letting the GC collect them)

pwk2• 17 years ago

The language (interpreter ? VM? ) leaks memory?

AFAIK the interpreter has no intrinsic leaks, but many ruby applications keep objects referenced beyond their intended life, preventing GC.

Edit: You extended your edit after I started responding :->

perhaps by holding onto objects and not letting the GC collect them

Yup, that's my understanding.

plinkplonk3• 17 years ago

"AFAIK the interpreter has no intrinsic leaks, "

ok if what you say is true then Brad's blog post is just wrong isn't it?. Either he is right or you are.

Holding onto objects sounds like something user code does so "ruby leaks" is (or should be) not correct usage I think.

I use python I don't use Ruby, but "Python leaks", as a claim, is different from "my program written in python leaks memory".

the blog post seems to imply it is Ruby's fault. At least it reads that way ("Ruby leaks") hence my confusion. Thanks for the clarification

EDIT: I stand corrected. It seems like Tom is right and the ruby interpreter leaks memory! Incredible!

mojombo4• 17 years ago

MRI has had a variety of memory leaks. I did an extensive search for the memory leaks on god, which you can read about here: http://groups.google.com/group/god-rb/browse_thread/thread/0.... I've verified that it's not an object referencing issue (which you can also read about in that link). Something in the threading code of MRI appears to be at fault, but I haven't had time to track that down yet.

teej3• 17 years ago

This analysis makes me a little sad. I want to like mojombo's work (I like Github a lot) but I've just had too many issues with his OSS.

mojombo4• 17 years ago

May I ask which other projects you've had problems with?

teej3• 17 years ago

God - Same issues stated in this article. I've had to move two different clients off of it to Monit.

Jekyll - I managed to access Github's database.yml in cleartext, I'm sure you remember that.

Fuzed - Never ran

Now, albeit, none of these had a 1.0 release and were practically abandoned before they reached it. I'm okay with that, because I really, really like Github.

grandalf7• 17 years ago

there is no need for you to make statements like that, sir. At least substantiate them and explain why you chose not to submit a patch, etc.

bradgessler4• 17 years ago

Chronic is bad ass; as-is github.

I've only been disappointed with God mainly because its marketed as being "like monit, only awesome" when its really not.

benburkert• 17 years ago

I think God is useful for "prototyping" an app environment. It's got a nice DSL and b/c it's ruby, it's turing complete. It's great for stage servers where flexibility and productivity are more important than a couple nines of uptime.

Monit's config is fairly straight forward, but the monit daemon can be quirky and unpredictable at times, and I usually have to hack out a bash script b/c monit is pretty limited on what it can actually do.

So I start with God, then translate that into Monit + scripts when I get to production.

mojombo4• 17 years ago

Just for the record, the correct spelling of my name is "Tom Preston-Werner." If you're going to attack me, please take a moment to spell my name right. Thanks!

grandalf7• 17 years ago

Tom, thanks for all your contributions to the open source community. I hope that one guy writing an immature article doesn't make you feel too negative.

I'm surprised that an article written with that tone made it to the top of HN.

mojombo4• 17 years ago

Thanks, grandalf! It means a lot to me for you to say that.

tdavis3• 17 years ago

Which part, exactly, is immature? Did I miss the part where he called Tom a "stupid fat head" or something? From what I read, the product does not work as advertised and in fact eventually causes itself to crash, yet the page begins with "monit except awesome". Hell, I loathe Ruby and I was even convinced it was a better alternative to monit!

I think anybody who releases open source software is to be commended; without it, most of us wouldn't have businesses. I have great respect for all contributors. That being said, just because you put something out there doesn't give you immunity against negative reviews. And it doesn't justify others, such as yourself, in berating those who give such reviews.

Most free software is forthcoming about its warts and issues. We're generally told when something should not be used for production. Instead, the pitch for god is that, well, it's God. I believe his tone was dead on for someone who felt betrayed by a piece of software that promised the world yet could not even maintain its own running state. After all that fighting, I'd be pissed too.

callmeed• 17 years ago

Would it be that hard to write a side-by-side comparison of God vs. Monit? You know, a bookmark/share-worthy post with some meat in it.

Was this just an attempt to stir the pot or were you just shooting from the hip?

FTR, I use God and its works fine for me.

defunkt• 17 years ago

God doesn't actually work.

We used god on FamSpam, currently use it on GitHub, and I've heard at least two massive Facebook apps (Friends for Sale and Rock Legends) use it to manage a large number of processes across a large number of servers.

For intelligently killing runaway processes (different attempts with different kill methods), monit is rather lacking. At CNET we ran into this again and again so I was very excited when Tom started god.

On one of our GitHub app slices, god has been running for 8 days and is using 8 megs of RAM. I can't speak for anyone else's setup, but I haven't seen the famed memory leak.

I would recommend god to anyone running a high trafficked Ruby-based site.

Use Monit with Rails, not God

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