XDebug Plugin¶
The XDebug plugin allows HTTP clients to debug the operation of the Traffic Server cache using the X-Debug header. The plugin is triggered by the presence of the X-Debug header in the client request. The contents of this header should be the names of the debug headers that are desired in the response. The XDebug plugin will remove the X-Debug header from the client request and inject the desired headers into the client response.
XDebug is a global plugin. It is installed by adding it to the plugin.config file.
Debugging Headers¶
The XDebug plugin is able to generate the following debugging headers:
- Via
- If the Via header is requested, the XDebug plugin sets the proxy.config.http.insert_response_via_str configuration variable to 3 for the request.
- X-Cache-Key
- The X-Cache-Key header contains the URL that identifies the HTTP object in the Traffic Server cache. This header is particularly useful if a custom cache key is being used.
- X-Cache
The X-Cache header contains the results of any cache lookup.
Value Description none No cache lookup was attempted. miss The object was not found in the cache. hit-stale The object was found in the cache, but it was stale. hit-fresh The object was fresh in the cache. skipped The cache lookup was skipped. - X-Milestones
- The X-Milestones header contains detailed information about how long the transaction took to traverse portions of the HTTP state machine. The timing information is obtained from the TSHttpTxnMilestoneGet() API. Each milestone value is a fractional number of seconds since the beginning of the transaction.