Fix Apache mod_jk or mod_proxy serving stale content

If your web app starts serving stale cached content when run behind mod_jk or mod_proxy with apache, it may be due to apache inserting a default expiration header.

You can confirm this by comparing the headers returned from apache and directly from your web app.  curl -i will show response headers:

curl -i http://example.com | head -20

To disable apache’s content expirations, add the following to your virtual host:

ExpiresActive Off

Here is the official Apache Documentation.