如何将清漆添加到Thumbor S3设置？

Question

客户需要原始的s3图像或缩略图图像

不带清漆的基本设置如下：

client => s3 image
client => thumbor => s3 image (thumbor gets s3 image and creates thumbnail for the client)

我想添加清漆以缓存图像。我应该在服务器之间的何处放置清漆？

1. client => s3 image becomse: client => varnish => s3 image
2. client => thumbor => s3 becomes any of the following I think

  1) client => varnish => thumbor => s3 image 
  2) client => thumbor => varnish => s3 image
  3) client => varnish => thumbor => varnish => s3 image

我想3）如果可以设置最好。.但是我想很难设置 1）vs 2）我应该选择哪一个呢？