“Can't Adapt” Errors with Satchmo

Posted On: February 26, 2010 at 6:21 a.m. by Neum

Having worked with Satchmo for over 2 years now (wow! how time does fly) we’ve done our share of upgrades along the way as Satchmo has continued to improve. One of the things we’ve battled for far too long are ubiquitous “can’t adapt” errors that were seemingly impossible to predict or track down. I’m happy to say I think we’ve finally tamed that beast. Our original server setup used Python 2.5, PostgreSQL and mod_python to connect it all because, well, that’s what the smart people over at Django recommended.

That setup ran very stable for us for about 6 months until we upgraded Satchmo and things got nasty. Not only were the database upgrades not fun, (documentation was sparse at the time) but we suddenly started getting can’t adapt errors along with other seemingly random errors. Needless to say we’ve tried lots of different setups and all of them seemed to clean up the errors for a time and then they would “magically” reappear.

When we switched to Webfaction over a year ago they only had mod_python connections as well and again things seemed to work OK. A few weeks ago, after upgrading Satchmo again we started to see “can’t adapt” error’s again. We decided it was time to chuck mod_python out the window and go with the now recommended mod_wsgi. WSGI seems faster and way more stable than mod_python ever was and most importantly the “can’t adapt” errors are gone. If you are getting these error I strongly recommend that you change to mod_wsgi. On Webfaction its a quick, fairly trivial change. I’ll write up a how to for those that use Webfaction and post it here.