Currently, the default-web.xml is treated as a deploytime option, in that it is
consulted only during the deployment of a webapp, at which time it is used to
augment the webapp's web.xml.
If the default-web.xml is modified before the server is restarted, any webapps
that are restarted will keep the original default-web.xml settings that they
inherited at the time when they were deployed. In order for any of the restarted
webapps to pick up the latest default-web.xml settings, they need to be redeployed.
The feedback received from many users has been that it would be more intuitive
for the default-web.xml to be treated as a runtime (as opposed to a deploytime)
option, so that any changes to it would become effective immediately after a
server restart, without the need to redeploy any of the already deployed webapps.