This question could go to one of several different lists, but I thought this might be a good place to start.
I have an application based on mod perl and the Template Toolkit. For session tracking I am using Apache::Session with the postgresql backend store. The issue I am having is that the postgresql store doesn't do any locking, which is causing some requests to read bad data, but I really want to keep the database as the backend store because it will scale a lot better if we need to have multiple servers access the same session data. What is happening is when a page that is loaded loads other pages (such as a frameset), sometimes the request for the first page doesn't finish before the other requests have already read the session data. It goes like this. - Request 1 fetches session - Request 2 fetches session - Request 1 changes some session information - Request 1 writes out session info - Request 2 writes out session info In our case a flag stating whether a user is logged in or not is stored in the session. If Request 1 logs out a user, Request 2 flags the user as logged in again when it writes out the session data. Solutions I have thought of so far include.. 1. Switch back to file based sessions, not what I want. 2. Switch to BerkelyDB sessions. Have had problems with database contention previously though which locks up the session manager so I'm uneasy about that one. 2. Keep a separate pool of cached connections just for the session database, and have those connections use a transaction isolation level that guarantees no dirty reads. Would use up a bunch of database connections. 3. Use the mysql backend store which supposedly has locking, but I already use postgresql and would rather not have to depend on two databases for one application. Any other ideas on possible solutions? Chris -- Report problems: http://perl.apache.org/bugs/ Mail list info: http://perl.apache.org/maillist/modperl.html List etiquette: http://perl.apache.org/maillist/email-etiquette.html
