Backend Storage

[eby]

Feel we should offer pluggable storage options.

Storage

1. Database
   • MongoDB - GridFS see http://www.mongodb.org/display/DOCS/GridFS
   • CouchDB? Supports Attachments
2. Filesystem
   • Default to pairtree to keep structure organized
   • Allow custom layout based on key for systems like Evergreen
3. Cloud Storage?
   • S3 and Google http://loose-bits.com/2011/10/16/node-sunny-cloud-library.html
   • RackSpace https://github.com/nodejitsu/node-cloudfiles

Derivatives

• Should we store the derivatives or create on the fly? Would say for filesystem it makes sense to store even if different directory structure. Allows easy CDN use.
• Store original? Or just largest of the derivative sizes?

[eby]

For evergreen the structure expected is as such for local overrides

/openils/var/web/opac/extras/ac/jacket/{large|medium|small}/ISBN

patch for record level out there which does:

...jacket/{large|medium|small}/r/RECORD_ID

[jblyberg]

GridFS might be overkill for mongodb storage. BSON documents can be up to 4MB, which I don't think we'll approach with cover images.

[eby]

Guess this asks the other question of upload interface. Admin interface of choice PUTS to a end point url? For those cases might be good to check the size of the image and use a derivative if too large. For example photos of physical objects, scans, etc.

[eby]

Moved this issue to standalone covercache SCAS/cloudcover#1