I would like to setup a SilverStripe instance in a load balanced environment. The database isn't an issue but I'm trying to figure out how to run a shared location for the assets. I've found this [https://github.com/edlinklater/silverstripe-cloudassets-s3]S3 cloud assets plugin however after installation and configuration it gives the error

Object->__call(): the method 'parent' does not exist on 'Image'

There isn't much to it and I've configured the yml as follows:

---
name: assetsconfig
---
CloudAssets:
  map:
    'assets/Uploads':
      Type: S3Bucket
      BaseURL: 'https://s3-ap-southeast-2.amazonaws.com/'
      Container: asset-container-test
      Region: ap-southeast-2
      ApiKey:
      ApiSecret:
      LocalCopy: true

Where have I gone wrong with this plugin or is there a better way to share the assets in a load balanced environment?

No need for modules, our network admins just set up a symlink via NFS for the assets directory which points to some other common place on the network which both sites can share.

Also, one other thing you probably need to look at is sessions as there are issues around this in load balanced environments. There is a good module for that which takes care of this called "Hybrid Sessions", see: https://github.com/silverstripe/silverstripe-hybridsessions