Provided by: trafficserver_5.3.0-2ubuntu2_amd64 bug


       cache.config     -     the     cache.config     file     (by     default,    located    in
       /usr/local/etc/trafficserver/) defines how Traffic Server caches web objects. You can  add
       caching rules to specify the following:

          · Not to cache objects from specific IP addresses

          · How long to pin particular objects in the cache

          · How long to consider cached objects as fresh

          · Whether to ignore no-cache directives from the server

          After  you  modify the cache.config file, navigate to the Traffic Server bin directory;
          then run the traffic_line -x command to apply changes. When you apply the changes to  a
          node  in a cluster, Traffic Server automatically applies the changes to all other nodes
          in the cluster.


       Each line in the cache.config file contains a  caching  rule.  Traffic  Server  recognizes
       three space-delimited tags:

          primary_destination=value secondary_specifier=value action=value

       You  can  use  more  than  one secondary specifier in a rule. However, you cannot repeat a
       secondary specifier. The following list  shows  the  possible  primary  destinations  with
       allowed values.

              A  requested domain name. Traffic Server matches the domain name of the destination
              from the URL in the request.

              A requested hostname. Traffic Server matches the hostname of the  destination  from
              the URL in the request.

              A requested IP address. Traffic Server matches the IP address of the destination in
              the request.

              A regular expression (regex) to be found in a URL.

       The secondary specifiers are optional in the cache.config file. The following  list  shows
       possible secondary specifiers with allowed values.

       port   A requested URL port.

       scheme A request URL protocol: http or https.

       prefix A prefix in the path part of a URL.

       suffix A file suffix in the URL.

       method A request URL method: get, put, post, trace.

       time   A time range, such as 08:00-14:00.

       src_ip A client IP address.

       The following list shows possible actions and their allowed values.

       action One of the following values:

              · never-cache configures Traffic Server to never cache specified objects.

              · ignore-no-cache  configures  Traffic Server to ignore all Cache-Control: no-cache

              · ignore-client-no-cache  configures  Traffic  Server  to   ignore   Cache-Control:
                no-cache headers from client requests.

              · ignore-server-no-cache   configures   Traffic  Server  to  ignore  Cache-Control:
                no-cache headers from origin server responses.

              · cluster-cache-local configures the cluster cache to allow for this content to  be
                stored locally on every cluster node.

              Change  the style of caching with regard to cookies. This effectively overrides the
              configuration parameter proxy.config.http.cache.cache_responses_to_cookies and uses
              the  same  values  with  the same semantics. The override happens only for requests
              that match.

              Preserves objects in cache, preventing  them  from  being  overwritten.   Does  not
              affect  objects  that  are  determined  not  to be cacheable. This setting can have
              performance issues, and  severely affect the cache.  For instance, if  the  primary
              destination  matches  all objects, once the cache is full, no new objects could get
              written as nothing would be evicted.  Similarly, for each cache-miss,  each  object
              would  incur  extra  checks  to  determine  if the object it would replace could be

              The value is the amount of time you want to keep the object(s) in  the  cache.  The
              following time formats are allowed:

              · d for days; for example: 2d

              · h for hours; for example: 10h

              · m for minutes; for example: 5m

              · s for seconds; for example: 20s

              · mixed units; for example: 1h15m20s

              For  objects  that are in cache, overrides the the amount of time the object(s) are
              to be considered fresh. Use the same time formats as pin-in-cache.

              Forces object(s) to become cached, as if they had a  Cache-Control:  max-age:<time>
              header.  Can be overruled by requests with cookies. The value is the amount of time
              object(s) are to be  kept  in  the  cache,  regardless  of  Cache-Control  response
              headers. Use the same time formats as pin-in-cache and revalidate.


       The  following example configures Traffic Server to revalidate gif and jpeg objects in the
       domain every 6 hours, and all other objects in every  hour.  The
       rules are applied in the order listed.

 suffix=gif revalidate=6h
 suffix=jpeg revalidate=6h

       Force a specific regex to be in cache between 7-11pm of the server's time for 26hours.

* time=19:00-23:00 ttl-in-cache=1d2h

       Prevent objects from being evicted from cache:
* pin-in-cache=1h