Diagnostic response headers
Look up the headers Azion adds to a response, on every request and with Pragma azion-debug-cache, and what each value carries.
Azion adds diagnostic headers to the responses it delivers. Two headers arrive on every response, and the request header Pragma: azion-debug-cache adds the location and cache headers. Under HTTP/2, the header names arrive in lowercase.
Headers on every response
These headers arrive on every response, with or without debug headers:
| Header | What it carries |
|---|---|
x-azion-request-id | A unique identifier of the request. The Azion error page shows the same value as Request ID, and Real-Time Events stores it in the requestId field. |
x-azion-edge-location | The code of the Azion data center that processed the request. The codes are published on the Azion Status Page, and the Azion error page shows the same value as Edge Location. |
To find a request in the logs by its identifier, refer to Gather information for Azion Support.
Debug headers
A request that carries Pragma: azion-debug-cache receives these headers in addition to the headers on every response. Without it, the response carries none of them.
| Header | What it carries |
|---|---|
x-azion-edge-pop | A location code, for debugging together with the cache headers. Its value can differ from x-azion-edge-location on the same response. |
x-cache | The cache status, the IP address of the server that answered the request, and the protocol |
x-cache-key | The cache key the copy is stored under, which is the argument a cache key purge takes |
x-cache-file | The MD5 hash of the cache key |
x-cache-since | The Unix timestamp of when the copy was stored |
x-cache-expire | The Unix timestamp of when the copy expires |
x-cache-expires-in | The seconds left until the copy expires |
x-cache-valid | The TTL configured for the copy, in seconds |
x-cache-config | The ID of the Azion configuration that served the request |
x-cache-id | An identifier of the request, different on each response |
x-cache-location | Returned with the other debug headers, for example / |
A - in place of the status in x-cache means no status: the content is restricted from caching. For every status value, such as HIT and MISS, refer to Cache keys.
Consecutive requests can reach different servers, and x-cache names the server that answered each one. To read the cache headers step by step, refer to Check the cache status of a response.