Re: [boost] ASIO TCP socket scalability for large scale connections

Subject: Re: [boost] ASIO TCP socket scalability for large scale connections
From: Richard Hodges (hodges.r_at_[hidden])
Date: 2018-12-24 03:24:11

On Mon, 24 Dec 2018 at 03:36, hh h <jupiter.hce_at_[hidden]> wrote:

> That is fabulous, I have been contemplating two connection models:
>
> (1) Keep and maintain each session connection in client lift time.
>
> (2) Open / close the session connection frequently on demand of each
> data transfer.
>
> While (1) is my preference, it'll depend on the performance, which
> connection model do you use?
>

It completely depends on the use case. The project I am currently working
on accepts connections from:
1. rest clients, who tend to disconnect and reconnect often
2. websocket clients, who tend to upgrade snd stay connected.
3. a debug connection which tends to stay open idle for some time
4. a "firehose" connection, which allows us to pump data in quickly for
testing purposes. This tends to connect and stay connected.

1 & 2 are internet-facing, so also have authentication, fair-scheduling and
DDoS protection to worry about.

Re security etc a common model these days is to put your server behind a
reverse proxy. I can't do that in my case because I need to measure and
respond to network back-pressure from each client.

For performance reasons, I have template hooks to change the threading,
memory allocation and object lifetime models. I default to std allocator,
shared_ptr and multiple threads per io_context because this is the most
easy to get wrong, but the framework I have written will support
thread-per-io_context and static memory management (i.e. a maximum number
of connections) without changing the code in the various io-aware objects.

>
> Thanks Richard and Vinnie.
>
> - jhh
>
>
>
> On 12/24/18, Richard Hodges via Boost <boost_at_[hidden]> wrote:
> > I've managed 100,000 simultaneous tcp connections to a c++ server using
> > boost::beast/asio on an appropriately configured fedora linux host.
> >
> > ASIO's memory overhead is minimal if written nicely.
> >
> >
> > On Sun, 23 Dec 2018 at 01:06, Vinnie Falco via Boost
> > <boost_at_[hidden]>
> > wrote:
> >
> >> On Sat, Dec 22, 2018 at 3:01 PM hh h via Boost <boost_at_[hidden]>
> >> wrote:
> >> > What will be the maximum connections a single ASIO TCP
> >> > socket server can handle?
> >>
> >> Asio doesn't contain magic or reinvent the wheel here, `basic_socket`
> >> is a very thin abstraction over a file handle representing a socket.
> >> You need to look to the limits of your operating system and
> >> configuration to know the baseline limit. And of course subtract from
> >> that any additional per-connection resources that your application
> >> uses.
> >>
> >> Regards
> >>
> >> _______________________________________________
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> >>
> >
> >
> > --
> > Richard Hodges
> > hodges.r_at_[hidden]
> > office: [phone]
> > home: [phone]
> > mobile: [phone] (this will be *expensive* outside Andorra!)
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> >
> > _______________________________________________
> > Unsubscribe & other changes:
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> >
>

-- 
Richard Hodges
hodges.r_at_[hidden]
office: [phone]
home: [phone]
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