AEMaaCS - How to remove default Cache-Control on HTML responses?

[Ganthimathi_R]

Hi All,

I am trying to disable cache for HTML responses. I have these rules already in dispatcher config,

<LocationMatch "^/content/.*\.html$">
Header always unset Cache-Control
Header always unset Expires
Header always set Cache-Control "no-store, no-cache, max-age=0, must-revalidate"
Header always set Pragma "no-cache"
Header always set Surrogate-Control "no-store"
</LocationMatch>

However, when I check response headers I still see this:

cache-control: no-store, no-cache, max-age=0, must-revalidate,max-age=300

It looks like max-age=300 is being appended somewhere. I want to know from where this default Cache-Control: max-age=300 is getting added? What is the recommended way to override / remove this so my own no-cache rules are effective?

Thanks in advance !

[Ganthimathi_R]

I missed to add this as part of my question. We do not have any other CDN on top of Fastly. And no other rules added on dispatcher for caching.

[Ganthimathi_R · Accepted solution]

Resolved the default HTML caching issue by following this documentation,https://experienceleague.adobe.com/en/docs/experience-manager-cloud-service/content/implementing/con...

Dispatcher configuration sets some default caching headers for text/html content type.

• by default, cached by the browser for five minutes, based on the cache-control header emitted by the Apache layer. The CDN also respects this value.
• the default HTML/Text caching setting can be disabled by defining the DISABLE_DEFAULT_CACHING variable in global.vars:

Define DISABLE_DEFAULT_CACHING

Copy

Toggle Text Wrapping

[SantoshSai]

Hi @Ganthimathi_R,

I think it's either (a) another vhost/dispatcher rule that sets max-age=300, often in default.vhost or a base file that loads after yours, or (b) publish-side code doing response.setHeader("Cache-Control", "max-age=300…"). Fastly won’t add 300 by itself.

Try this:

<LocationMatch "^/content/.*\.html$">
  # wipe both header tables
  Header unset Cache-Control
  Header always unset Cache-Control
  Header unset Expires
  Header always unset Expires

  # set once, at the very end
  Header always set Cache-Control "no-store, no-cache, max-age=0, must-revalidate"
  Header always set Pragma "no-cache"
  Header always set Surrogate-Control "no-store"
</LocationMatch>

also:

• Ensure this block is in the vhost that loads last (or move it to default.vhost), so nothing overwrites it later.

• Grep your codebase for setHeader("Cache-Control" and remove any max-age=300 on HTML responses.

and verify:

curl -I https://your.site/.../page.html | tr -d '\r' | egrep -i 'cache-control|surrogate-control'

You should see a single Cache-Control (your value) and Surrogate-Control: no-store.

[Karishma_begumSh]

Hi @Ganthimathi_R 

The max-age=300 is coming from dispatcher’s default caching (not Apache).

In dispatcher.any, allow dispatcher to forward your custom headers instead of appending its own:

/cache
{
  /headers
  {
    "Cache-Control"
    "Pragma"
    "Surrogate-Control"
  }
}

Then your <LocationMatch> rules will take effect and max-age=300 won’t be added.

Hope this helpful.:)

Regards,

Karishma.