Re: [Tutor] continuouse loop
Thanks or your replies, in fact I need my server to recieve queries from some 40 clients, process the recieved text (some calculations) send a response back to them, in my previouse application I used a database, (they entered thier queries into the db my calculating script looks at new records in db every 2 minutes inserts the answers into the db too so that the users could see them on thier interface. but now I need to move to a server/client design because at the time i had created this program I didn't have much time I had to put it into production. Right now I am working on some code using the SOCKET module as it was the only module that allows inter-process communication was simple enough for me to understand how it works. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] continuouse loop
Monika Jisswel wrote: Thanks or your replies, in fact I need my server to recieve queries from some 40 clients, process the recieved text (some calculations) send a response back to them, in my previouse application I used a database, (they entered thier queries into the db my calculating script looks at new records in db every 2 minutes inserts the answers into the db too so that the users could see them on thier interface. but now I need to move to a server/client design because at the time i had created this program I didn't have much time I had to put it into production. Assuming your 40 clients represent real human users, and not automated processes, I almost always approach this kind of problem with a web application, usually a cgi script or simple mod_python handler. That way I can spend more time solving the problem at hand, and less on client/server design details or client installation/upgrade scheduling. But then browsers and web servers are very common in our environment. Right now I am working on some code using the SOCKET module as it was the only module that allows inter-process communication was simple enough for me to understand how it works. In that case, you might want to have a look at the SocketServer module also. http://www.python.org/doc/lib/module-SocketServer.html HTH, Marty ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] continuouse loop
Would a program using a continuouse loop such as in this code take up resources on the system if left for long period ? import sys while 1: self.data = sys.stdin.readline() self.function_1(data) What are my other options is I want to have a running program other programs communicate with it get responses from it ? ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] continuouse loop
Monika Jisswel [EMAIL PROTECTED] wrote Would a program using a continuouse loop such as in this code take up resources on the system if left for long period ? Any running program takes up some resources but whether this one would increase its resource usage over time, which I assume is what you want to know, would depend on what it did with self.data and what happened in self.function_1. If function_1 did nothing that was resource intensive - like build a big list in memory or open a new file each time it was called (and not release it) - then it would be fine. But if function_1 stored data in a list or opened a new comms port on each call then yes it will eat up resources. import sys while 1: self.data = sys.stdin.readline() self.function_1(data) What are my other options is I want to have a running program other programs communicate with it get responses from it ? The trick to writing long running processes such as Windows services and Unix daemons is to ensure they are either stateless (the create use and free the needed resources in each operation) or utilise pools (pre-allocated sets of resources that are allocated to a function as needed and released by the function when done - if you run out of pool you take a decision to enlarge the pool or to stop servicing requests until resource becomes available - possibly using a queue if instant response is not critical) Thee are framweworks around, such as twisted, that help with these tasks. HTH, -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] continuouse loop
Monika Jisswel wrote: Would a program using a continuouse loop such as in this code take up resources on the system if left for long period ? import sys while 1: self.data = sys.stdin.readline() self.function_1(data) Not much, I would think, until something is written to stdin of this program, and then it would depend on what function_1 does. What are my other options is I want to have a running program other programs communicate with it get responses from it ? If I understand what you're asking, there are a few options outlined in the python library reference, here: http://docs.python.org/lib/ipc.html I would add named pipes as another option for *nix, windows may have something similar. And, depending on what you're trying to accomplish maybe xmlrpclib, soappy, pyro, or perhaps even cgi. HTH, Marty ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
