Wildfly 8 - HTTP cache headers tuning for rich client web application

wildfly_httpcache.md

Introduction

This Gist describes how to tune HTTP browser cache expiration for static contents served by Wildfly Undertow web server, as per RFC-2616 section 13.

Wildfly configuration

Description

In order to change HTTP browser cache behavior, a "Cache-Control" HTTP header has to be added to static content HTTP responses returned by Undertow.

Undertow subsystem configuration (standalone.xml)

NOTE: "..." means existing xml config elements to be kept

<subsystem xmlns="urn:jboss:domain:undertow:1.2">

  ...

  <server name="default-server">

    ...

    <host name="default-host" alias="localhost">
        ...
        <filter-ref name="custom-max-age" predicate="path-suffix['.js'] or path-suffix ['.json'] or path-suffix ['.html'] or path-suffix ['.css'] or path-suffix ['.jpg'] or path-suffix ['.jpeg'] or path-suffix ['.png'] or path-suffix ['.gif']"/>
    </host>
  </server>

  ...

  <filters>

      ...
      
      <response-header name="custom-max-age" header-name="Cache-Control" header-value="max-age=600, public"/>
  </filters>
</subsystem>

Description

A Cache-Control header will be added to HTTP responses header for static files having extensions: ".js, .json, .html, .css, .jpg, .jpeg, .png, .gif". (Complete list of handlers predicates, such as "path-suffix", is availaible here)

This header has a "max-age=600, public" value which tells to browser to expire these static content files after 600 seconds, as described in RFC-2616 section 14.9.3. (see this other section for public value description)

Links

• RFC-2616 - section 13, section 14.9.3 and section 14.9.1
• Predicates Attributes and Handlers

@remibantos Do you know if there is a way to set a default cache-filter as well? For example, to have a default set a No-Cache EXCEPT for the static content indicated in your predicate.