Caching can be disabled:
- at the individual URL level,
- at the browser level, and
- at the site level.
Disabling caching at the individual URL level
To disable caching at the individual URL level:
- Create a request setting that always forces a pass.
- Add a condition to the request setting that looks for specific URLs.
- Activate the new version of your service to enable the setting.
Disabling caching at the browser level
Theoretically, all browsers should follow the stated rules of the HTTP standard. In practice, however, some browsers don't strictly follow these rules. The following combination of headers seems to force absolutely no caching with every browser we've tested.
1 2 3 Cache-Control: no-cache, no-store, private, must-revalidate, max-age=0, max-stale=0, post-check=0, pre-check=0 Pragma: no-cache Expires: 0
In addition, IE8 has some odd behavior to do with the back button. Adding
Vary: * to the headers seems to fix the problem.
If you want your content cached in Fastly but not cached on the browser, you must not add these headers on your origin server. Instead, add these as new Headers on the Content page and be sure the Type is set to Response.
Disabling caching at the site level
You can disable caching at the site level by creating a VCL Snippet to pass on all requests to your service:
- Log in to the Fastly web interface.
- From the All services page, select the appropriate service. You can use the search box to search by ID, name, or domain.
- Click the Edit configuration button and then select the option to clone the active version. The Domains page appears.
- Click the VCL Snippets link. The VCL Snippets page appears.
Click Create Snippet. The Create a VCL snippet page appears.
- In the Name field, enter an appropriate name (e.g.,
Pass All Requests).
- From the Type controls, select within subroutine.
- From the Select subroutine menu, select recv (vcl_recv).
In the VCL field, add the following condition:
- Click Create to create the snippet.
- Click the Activate button to deploy your configuration changes.
All requests will continue to be passed until you remove return(pass); from vcl_recv in your VCL or you delete this snippet.