Re: Custom server

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Hry Mark,


While I'm significantly less qualified than many on the POE list, I will gi=
ve it a shot.


Part of what POE has taught me is to organize my code into more distinct st=
eps where  I can stack them up and execute them asynchronously.


Part of the thing with Fork is that when you look under the covers, it clon=
es the process.  So, every time you fork, you create a new instance.


With POE, you organize the things you need to do in subroutines accessed vi=
a Call backs.  When you need to something that blocks, you use a Run Wheel =
to keep your process working.=20


Everything starts off with a _start.  In this sub, start up your SocketFact=
ory stuff, your Run Wheels, etc.  If these need to be done is  specific ord=
er, use a yield yo callback to the stack a separate subroutine to start the=
 other things.


As things start running and you accept connections, each accept sets up cal=
lbacks for each thing you need to do.


Look at delay_add to setup a delayed timer. Wait and sleep block... And whe=
n they do, so does everything else.


I built an event management system capable of handling and processing > 1 m=
illion events a minute.


HTH,


Dougie!!!








-----Original Message-----
From: Mark Richards <[email protected]>
To: poe <[email protected]>
Sent: Sun, Dec 9, 2012 3:15 pm
Subject: Custom server


I think POE would be a good choice for what I am about to describe, but=20
there are a few bits I am not certain about (how to implement; whether=20
it's possible to implement).

I already have a working model of a server that listens on a designated=20
port (built in php!). It forks each connection request and handles these=20
independently.  There may be one or 100 clients connecting at any time. =20
However there is the problem of zombies, and the lack of centralized=20
control and reporting.  I want to build this in perl, and feel POE would=20
be a good choice.

My server waits for a connection.  The client, once connected, sends a=20
header that contains its ID and WAN IP address.  The server reads this,=20
and responds by either continuing some communications with the client,=20
or dropping the connection if it is not validated.

A valid connection provides a MODBUS ASCII session with a MODBUS network=20
attached to the client.  So the server instance sends some MODBUS=20
commands and gets data in response.  In the present implementation the=20
server keeps the connection alive for 10 minutes (this is a design=20
requirement - don't ask!), and then drops the connection (this is where=20
we get the zombies from).

What I need POE to do is the same thing, but for this I think I need a=20
manager of some kind that will, based on the state of the exchange,=20
dispatch the proper request.  Each remote may require a different set of=20
requests, which further complicates things.

I've thrown together a simple POE version of my server.  It simply=20
accepts the connection and reads in the first data from the client (a=20
header).  What's missing is a way to dispatch requests dynamically and=20
also to wait without making the whole POE instance wait.

Hoping I have described this adequately, and that the experienced out=20
there might offer some suggestions as to how to approach this - and=20
whether POE is the right move.

Thanks!


=20


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