Re: The benchmark of Artanis: guile server, Fibers, and Ragnarok

[Nala Ginrut <nalaginrut@gmail.com>]

 hi Arne!
Thanks for the reply!


On Sat, May 12, 2018 at 4:00 AM, Arne Babenhauserheide <arne_bab@web.de> wrote:

> Ragnarok and pristine Guile both let specific requests starve, while
> fibers accepts higher average latency to avoid high maximum latency.
>
> Is this repeatable? If yes, then you can see the difference in
> scheduling here: With fibers none of the 1000 requests has to wait more
> than a second, while with pristine guile and with ragnarok some requests
> can stall everything. If you have a lot of resources being loaded to
> display a page, the maximum latency is the effective page load delay.

Yes, Ragnarok is not preempt-able yet, so it may delay too long when a
big request stall.
There're only 4 situations for a task could be scheduled:
1. I/O blocking
2. The socket buffer is full (users may tweak it)
3. Resources are insufficient to allocate (listening sockets, DB
connection pool, etc...)
4. Developers call (break-task) explicitly in the handler

I would like to make it preempt-able, but I still don't get the skill
how to do it from outside of a delimited-continuation.
And I would like to implement a better scheduler, for now it's just
simple FIFO. But I need to know how many size left
when suspend-able ports were blocking. It seems there's not interface
for me to get that size. Maybe there should be
a patch for it.


> I left out the 4-instance ragnarok test, because its coping with latency
> in the face of overload is not comparable, since it is less highly
> overloaded (and that’s the feature which struck me while reading).
>
> And anyway: These are already pretty good numbers. They don’t achieve
> the level of static file serving with massive caching (in my tests
> lighttpd could get more than a factor 2 increase over (fibers web
> server)), but it’s already on a level where it could support around 500
> active users on a single instance running on consumer hardware.

I have to mention that Django of Python got 700 req/s in the same test
under my same condition.
But it's trivial since Django is not good at performance but the
security and full-featured web stuffs.
I think the best choice is that to use Nginx for reverse-proxy, since
Nginx handles static files that may get 300,000 req/s though-out.
No one can compete with it for static files handling.

> What I also see is that Artanis seems to have low overhead. How do the
> numbers change with more complex pages?

I have to mention that even I have modified the code to do real json
serialization from assoc-list, the test result still remains.
But OK it's the credit of the author of guile-json ;-)
For more complex pages and DB based dynamic pages, I've tested before
roughly, it's not bad. And I have many ideas to optimize it. So
no hurry to test the current things.

I'm going to submit Artanis to Techempower for full tests, there'll be
more con-vincible test result. But before that, I have to finish all
the
features in my TODO, and make it more stable to avoid crash. The
version 0.2.5 is already very stable by eliminated many exceptions.
But I still need
more users to test it and feed back.

Best regards.