Re: website catcher
jwaixs wrote: I need some kind of database that won't exit if the cgi-bin script has finished. This database need to be open all the time and communicate very easily with the cgi-bin framwork main class. Maybe long-running multi-threaded processes for FastCGI, SCGI or similar is what you're looking for instead short-lived CGI-BIN programs forked by the web server. Ciao, Michael. -- http://mail.python.org/mailman/listinfo/python-list
website catcher
Hello, I'm busy to build some kind of webpage framework written in Python. But there's a small problem in this framework. This framework should open a page, parse it, take some other information out of it and should store it in some kind of fast storage. This storage need to be very fast so every one who will ask for this page will get a parsed page returned from this storage (catcher?). But how could I design a good webcatcher? Is this possible in python, because it should always run. Which won't work with cgi-bin pages because the quit after the execute something. Or should it be build in c and imported as a module or something? Thank you, Noud Aldenhoven -- http://mail.python.org/mailman/listinfo/python-list
Re: website catcher
You can catch the content of an url like this: http://www.python.org/doc/current/lib/node478.html, from here you can parse it, and the store the result e.g. in dictionary, you will have a very well performing solution like this. -- http://mail.python.org/mailman/listinfo/python-list
Re: website catcher
Thank you, but it's not what I mean. I don't want some kind of client parser thing. But I mean the page is already been parsed and ready to be read. But I want to store this page for more use. I need some kind of database that won't exit if the cgi-bin script has finished. This database need to be open all the time and communicate very easily with the cgi-bin framwork main class. -- http://mail.python.org/mailman/listinfo/python-list
Re: website catcher
jwaixs wrote: Thank you, but it's not what I mean. I don't want some kind of client parser thing. But I mean the page is already been parsed and ready to be read. But I want to store this page for more use. I need some kind of database that won't exit if the cgi-bin script has finished. This database need to be open all the time and communicate very easily with the cgi-bin framwork main class. Why does it need to be open? Store it in a pickled file, an load read that pickle when you need it. Or not even as pickle, just as file in the FS. Basically what you are talking about is a webserver - so just use that. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: website catcher
If I should put the parsedwebsites in, for example, a tablehash it will be at least 5 times faster than just putting it in a file that needs to be stored on a slow harddrive. Memory is a lot faster than harddisk space. And if there would be a lot of people asking for a page all of them have to open that file. if that are 10 requests in 5 minutes there's no real worry. If they are more that 10 request per second you really have a big problem and the framework would probably crash or will run uber slow. That's why I want to open the file only one time and keep it saved in the memory of the server where it don't need to be opened each time some is asking for it. Noud Aldenhoven -- http://mail.python.org/mailman/listinfo/python-list
Re: website catcher
jwaixs wrote: If I should put the parsedwebsites in, for example, a tablehash it will be at least 5 times faster than just putting it in a file that needs to be stored on a slow harddrive. Memory is a lot faster than harddisk space. And if there would be a lot of people asking for a page all of them have to open that file. if that are 10 requests in 5 minutes there's no real worry. If they are more that 10 request per second you really have a big problem and the framework would probably crash or will run uber slow. That's why I want to open the file only one time and keep it saved in the memory of the server where it don't need to be opened each time some is asking for it. I don't think that's correct. An apache serves static pages with high speed - and slow hardrives means about 32MByte/s nowadays. Which equals 256MBit/s - is your machine connected to a GBit connection? And if it's for internet usage, do you have a GBit connection - if so, I envy you... And if your speed has to have that high, I wonder if python can be used at all. BTW, 10 reqeuest per seconds of maybe 100KB pages is next to nothing - just 10MBit. It's not really fast. And images and the like are also usually served from HD. You are of course right that memory is faster than harddrives. but HDs are (ususally) faster than network IO - so that's your limiting factor, if at all. And starting CGI subrpocesses introduces also lots of overhead - better use fastcgis then. I think that we're talking about two things here: - premature optimization on your side. Worry about speed later, if it _is_ an issue. Not now. - what you seem to want is a convenient way of having data serverd to you in a pythonesque way. I personally don't see anything wrong with storing and retrieving pages from HD - after all, that's where they end up anyway ebentually. So if you write yourself a HTMLRetrieval class that abstratcs that for you and 1) takes a piece of HTML and stores that, maybe associated with some metadata 2) can retrieve these chunks of based on some key you are pretty much done. If you want, you can back it up using a RDBMS, hoping that it will do the in-memory-caching for you. But remember that there will be no connection pooling using CGIs, so that introduces overhead. Or you go for your own standalone process that serves the pages through some RPC mechanism. Or you ditch CGIs at all and use some webframework that serves from an permanenty running python process with several worker threads - then you can use in-process memory by global variables to store that memory. For that, I recommend twisted. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: website catcher
Well, thank you for your advice. So I have a couple of solutions, but it can't become a server at its own so this means I will deal with files. Thank you for your advice, I'll first make it work... than the server. Noud Aldenhoven -- http://mail.python.org/mailman/listinfo/python-list
Re: website catcher
maybe look at Harvestman http://cheeseshop.python.org/HarvestMan/1.4%20final -- http://mail.python.org/mailman/listinfo/python-list
Re: website catcher
jwaixs [EMAIL PROTECTED] writes: If I should put the parsedwebsites in, for example, a tablehash it will be at least 5 times faster than just putting it in a file that needs to be stored on a slow harddrive. Memory is a lot faster than harddisk space. And if there would be a lot of people asking for a page all of them have to open that file. if that are 10 requests in 5 minutes there's no real worry. If they are more that 10 request per second you really have a big problem and the framework would probably crash or will run uber slow. That's why I want to open the file only one time and keep it saved in the memory of the server where it don't need to be opened each time some is asking for it. While Diez gave you some good reasons not to worry about this, and had some great advice, he missed one important reason you shouldn't worry about this: Your OS almost certainly has a disk cache. This means that if you get 10 requests for a page in a second, the first one will come off the disk and wind up in the OS disk cache. The next nine requests will get the pages from the OS disk cache, and not go to the disk at all. When you keep these pages in memory yourself, you're basically declaring that they are so important that you don't trust the OS to cache them properly. The exact details of how your using extra memory interact with the disk cache vary with the OS, but there's a fair chance that you're cutting down on the amount of disk cache the system will have available. In the end, if the OS disagrees with you about how important your pages are, it will win. Your pages will get paged out to disk, and have to be read back from disk even though you have them stored in memory. With extra overhead in the form of an interrupt when your process tries to access the swapped out page, at that. A bunch of very smart people have spent a lot of time making modern operating systems perform well. Worrying about things that it is already worrying about is generally a waste of time - a clear case of premature optimization. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
