Fastly-Debug-TTL
Provides timing information for cached resources.
Fastly writes this header into responses. It is proprietary to Fastly.
When Fastly-Debug is present in a request, this header is attached to the response and contains information on various timings.
Fastly-Debug-TTL: H cache-jfk1026-JFK 41733294.335 864000.000 2273The syntax is:
{cacheStatus} {serverIdentity} {remainingTTL} {staleIfErrorTTL} {age}cacheStatus: Whether or not the object was found in cache.Hfor hit,Mfor miss. "Hit" in this simplified classification includes all responses where a request was not forwarded to origin.serverIdentity: The value ofserver.identity.remainingTTL: The amount of time in seconds for which the object will remain fresh in the cache (seeobj.ttl).staleIfErrorTTL: The amount of time in seconds for which the object will be served stale if no backends are available (see staleness and revalidation).age: The number of seconds for which the object has been in cache.
WARNING: remainingTTL and staleIfErrorTTL are only available when the server handling the request has the object in its own local cache. Otherwise those values will be shown as -. This is typically the case when a cache hit results from clustering, where the request has been forwarded from the server that initially handled it, to the one that has the item in cache. As a result it may be necessary to fetch the URL you are testing repeatedly until you see those values populated.
