For our customer we're using the OnePica_ImageCdn
extension which is working fine. Of course we're using the database for the setting 'File Result Cache'. The other option is using file based cache which will be a lot slower.
But still the database driven cache generates a lot of queries. The shop of our customer is pretty big and with a lot of content which results in an average of 25k cpm on the imageCdn caching table in MySQL. We would like to reduce this. Redis cache en Varnish cache are already set up for this webshop. Redis cache isn't doing anything for the CDN cache at the moment but Varnish is of course.
I think it would be useful if the OnePica_ImageCdn
extension uses Redis cache as the first caching layer but this isn't supported by the extension as far as I know.
So what do you guys suggest as an approach to reduce the database load on the imageCdn caching table in MySQL?
PS. the magento installation is CE 1.8.1.0 with all the security patches applied of course.
OnePica_ImageCdn
itself. It is mentioned by the OP, but the core of the question is about caching tactics in general.