BootstrapFilter

The BootstrapFilter is intended to protect the Content Engine from traffic during startup. When the Content Engine is started or restarted, its bootstrap service primes the system by sending fake requests to itself. These requests force the Content Engine to initialize various subsystems, load content from the database and so on, until the system is fully operational and ready to respond to requests at full speed.

While this process is underway, the BootstrapFilter only passes through requests from the bootstrap service. For all other requests it returns an HTTP 503 response (Service Unavailable).

The BootstrapFilter is configured in WEB.XML as follows:

<filter>
  <filter-name>BootstrapFilter</filter-name>
  <filter-class>
    com.escenic.presentation.servlet.BootstrapFilter
  </filter-class>
  <init-param>
    <param-name>oncePerRequest</param-name>
    <param-value>true</param-value>
  </init-param>
</filter>
Configuration Parameters
oncePerRequest

If set to true, then the filter is only executed for the initial request. If set to false, then the filter is executed for every request, which on some servers may mean that it is re-applied each time an include operation calls a new JSP file.

Request Scope Attributes

This filter sets no request scope attributes.