ifndef::hazelcast[]
:hazelcast: https://docs.hazelcast.org/docs/4.0/manual/html-single/index.html
endif::hazelcast[]

== Caching

=== Platform configuration
Caching is provided by https://hazelcast.org/[Hazelcast^].

A central configuration file is used to configure Hazelcast. The location of this file is specified by the platform property `cacheConfig` 
(see {manager-guide}#platform-properties[Platform properties^]).

Usually, `cacheConfig` points to `WEB-INF/conf/hazelcast.xml`, which might look as follows for multicast replication:
[source, xml]
----
include::listing/hazelcast.xml[]
----

For further details about configuring Hazelcast, check out it's {hazelcast}[Reference Manual^].

Also check out the section about caching in the {manager-guide}#caching[Manager User Manual^].

=== Site configuration
There are several site-scoped properties to configure caching.

* `cacheEnabled` (default: `false`) +
Set to `true` to enable caching for the site.
* `cacheExceptions` +
Default: + 
+
[source,]
----
/health
/manager
----
URL path prefixes which are never cached, as a multiline value. Contains one prefix per line. +
*Example:*
+
[source,]
----
/service/appng/my-application
/service/my-site
----
+
TIP: An entry in `cacheExceptions` beats an entry in `cacheTimeouts`.
* `cacheTimeouts` +
The path specific cache timeouts, as a multilined value. The format is `path-prefix = <TTL in seconds>`. +
Optionally, with appending `,<client TTL in seconds>`, you can  control the https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control[Cache-Control^] 
HTTP header that is sent to the client. +
Contains one path-prefix per line. +
*Example:*
+
[source,]
----
# same TTL for internal cache and client:
# Cache-Control: max-age=7200
/service/appng/cached-application = 7200
# different TTL for internal cache and client:
# Cache-Control: max-age=14400
/service/thesite = 3600,14400
# disable client caching:
# Cache-Control: no-cache,no-store,max-age=0
# Expires: Thu, 01 Jan 1970 00:00:00 GMT 
/en/index.html = 1800,0
----
* `cacheTimeoutsAntStyle` (default: `true`) +
When set to `true`, the path-prefixes defined in `cacheTimeouts` can use https://ant.apache.org/manual/dirtasks.html#patterns[Ant-style path matching^].
* `cacheTimeToLive` (default: `1800`) +
The default TTL for a cache entry in seconds, if there's no matching path defined in `cacheTimeouts`.
* `cacheStatistics` (default: `false`) +
Set to `true to` enable caching statistics
* `cacheWatchRepository` (default: `false`) +
Set to `true` to watch the repository folder for changes and invalidate cache elements, if necessary.
* `cacheWatcherRuleSourceSuffix` (default: `((\?\S+)?)`) +
The suffix to be removed from a `<from>`-rule element when parsing the rules from `urlrewrite.xml` for the repository watchers. See also the {developerguide}#beautifying-urls[Beautifying URLs^] section from the developer's guide,
* `cacheClearOnShutdown` (default: `true`) +
Set to `true` to clear the cache on a site shutdown/reload.