|
Stefan C. Kremer
skremer at q.cis.uoguelph.ca
Thu Feb 13 21:14:03 EST 2003
Thanks for the reply Greg. Actually I'm in the process of writing my own session management tool (I looked at a few others and none of them really suited my needs; plus I wanted to do it myself for the learning experience). So now I'm trying to figure out what my options are for implementing persistent data. Right now I'm identifying my session by means of a cookie, so that part's not a problem. My challenge now is, how to associate more data with the cookie (session) in a way that persists accross http requests. The three options I'm working with right now are: (1) just store in the info in the global namespace, keyed on the cookie. This seems to me to be the simplest, and fastest solution. The drawbacks are that queries that go to a different process won't have access to my data. Now that httpd is threaded, this happens much less often. In fact, it seems to only occur when I explicitly restart apache or reboot my machine (which is basically never since I don't run Windows and have a UPS). (2) Save it to a file. This is slow, but otherwise would work fine if I implement appropriate file locking. (3) Send it via a socket to another process which all mod_python processes share. (4) Some combination of (1) with (2 or 3), which writes the data away and only retrieves it from (2,3) if its not in the local namespace. I'm not sure how much I will gain from not retrieving data from (2,3) most of the time. Are there any good options which I have overlooked? Does my evaluation of the alternatives seem sound? Any suggestions or comments. Thanks for any advice anyone wants to pass my way. -SK On Thu, 13 Feb 2003, Gregory Bond wrote: > > skremer at q.cis.uoguelph.ca said: > > So should I be able to just store a variable in my local namespace and > > then return to it the next time I make an http connection? Or might > > my next connect be executing python in a different namespace for some > > reason?!? > > It might work in certain restricted circumstances, but it's likely to be > unreliable. You can't know when Apache will decide it's time for a new > process. You can't know when the apache process gets re-configured or > restarted. You can't know when another unrelated session to the same > application will begin. > > You would be much better off to look at some of the session management tools > that work with mod_python and handle the problem properly. I use Albatross > (http://www.object-craft.com.au/projects/albatross/) but that does a whole > heap more than just session management. Others have recommended PSO > (http://www.scriptfoundry.com/modules/pso/). > > Greg. > > > -- -- Dr. Stefan C. Kremer, Associate Prof. Reynolds Building, 106 Dept. of Computing and Information Science University of Guelph, Guelph, Ontario N1G 2W1 WWW: http://q.cis.uoguelph.ca/~skremer Tel: (519)824-4120 Ext.58913 Fax: (519)837-0323 E-mail: skremer at uoguelph.ca
|