.. Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. .. configfile:: cache.config ============ cache.config ============ The :file:`cache.config` file (by default, located in ``/opt/trafficserver/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 .. important:: After you modify the :file:`cache.config` file, navigate to the Traffic Server bin directory; then run the :option:`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. Format ====== Each line in the :file:`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. .. _cache-config-format-dest-domain: ``dest_domain`` A requested domain name. Traffic Server matches the domain name of the destination from the URL in the request. .. _cache-config-format-dest-host: ``dest_host`` A requested hostname. Traffic Server matches the hostname of the destination from the URL in the request. .. _cache-config-format-dest-ip: ``dest_ip`` A requested IP address. Traffic Server matches the IP address of the destination in the request. .. _cache-config-format-url-regex: ``url_regex`` A regular expression (regex) to be found in a URL. The secondary specifiers are optional in the :file:`cache.config` file. The following list shows possible secondary specifiers with allowed values. .. _cache-config-format-port: ``port`` A requested URL port. .. _cache-config-format-scheme: ``scheme`` A request URL protocol: http or https. .. _cache-config-format-prefix: ``prefix`` A prefix in the path part of a URL. .. _cache-config-format-suffix: ``suffix`` A file suffix in the URL. .. _cache-config-format-method: ``method`` A request URL method: get, put, post, trace. .. _cache-config-format-time: ``time`` A time range, such as 08:00-14:00. .. _cache-config-format-src-ip: ``src_ip`` A client IP address. The following list shows possible actions and their allowed values. .. _cache-config-format-action: ``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`` headers. - ``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. .. _cache-responses-to-cookies: ``cache-responses-to-cookies`` Change the style of caching with regard to cookies. This effectively overrides the configuration parameter :ts:cv:`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. .. _cache-config-format-pin-in-cache: ``pin-in-cache`` 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 overwritten. 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 .. _cache-config-format-revalidate: ``revalidate`` 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``. .. _cache-config-format-ttl-in-cache: ``ttl-in-cache`` Forces object(s) to become cached, as if they had a Cache-Control: max-age: