Why IllegalStateException occurs when configuring http access log in jetty.xml

Issue

• When configuring "jetty.xml" for an http access log cxf crashes with an "IllegalStateException"

2014-12-01 11:36:04,663 | ERROR | FelixStartLevel  | WebApplication                   | 168 - org.ops4j.pax.web.pax-web-extender-whiteboard - 3.0.6 | Registration skipped for [ServletWebElement{mapping=DefaultServletMapping{httpContextId=null,urlPatterns=null,initParams={},servlet=org.apache.cxf.transport.servlet.CXFNonSpringServlet@148be2a3, alias=/cxf, servletNamecxf-osgi-transport-servlet}}] due to error during registration
java.lang.IllegalStateException: STARTED
    at org.eclipse.jetty.server.handler.HandlerCollection.setHandlers(HandlerCollection.java:80)[92:org.eclipse.jetty.aggregate.jetty-all-server:8.1.14.v20131031]
    at org.eclipse.jetty.server.handler.HandlerCollection.addHandler(HandlerCollection.java:282)[92:org.eclipse.jetty.aggregate.jetty-all-server:8.1.14.v20131031]
    at org.eclipse.jetty.servlet.ServletContextHandler.<init>(ServletContextHandler.java:150)[92:org.eclipse.jetty.aggregate.jetty-all-server:8.1.14.v20131031]
    at org.eclipse.jetty.servlet.ServletContextHandler.<init>(ServletContextHandler.java:116)[92:org.eclipse.jetty.aggregate.jetty-all-server:8.1.14.v20131031]
.
.
2014-12-01 11:36:06,572 | ERROR | FelixStartLevel  | fabric-redirect                  | 103 - io.fabric8.fabric-redirect - 1.0.0.redhat-379 | [io.fabric8.redirect(44)] The activate method has thrown an exception
java.lang.IllegalStateException: STARTED
    at org.eclipse.jetty.server.handler.HandlerCollection.setHandlers(HandlerCollection.java:80)
    at org.eclipse.jetty.server.handler.HandlerCollection.addHandler(HandlerCollection.java:282)
    at org.eclipse.jetty.servlet.ServletContextHandler.<init>(ServletContextHandler.java:150)

• Prior to adding the config, cxf is functional but after adding the config, cxf returns a 404 error but eh access log is functional.

• The "jetty.xml" has the following added entry in it which seems to be causing the issue.

    <Set name="handler">
      <New id="Handlers" class="org.eclipse.jetty.server.handler.HandlerCollection">
         <Set name="handlers">
            <Array type="org.eclipse.jetty.server.Handler">
               <Item>
                 <New id="Contexts" class="org.eclipse.jetty.server.handler.ContextHandlerCollection"/>
                </Item>
                <Item>
                  <New id="DefaultHandler" class="org.eclipse.jetty.server.handler.DefaultHandler"/>
                </Item>
                <Item>
                  <New id="RequestLog" class="org.eclipse.jetty.server.handler.RequestLogHandler"/>
                </Item>
            </Array>
        </Set>
      </New>
    </Set>

    <Ref id="RequestLog">
      <Set name="requestLog">
        <New id="RequestLogImpl" class="org.eclipse.jetty.server.NCSARequestLog">
          <Arg><SystemProperty name="KARAF_HOME" default="./data/log"/>/yyyy_mm_dd.http.log</Arg>
          <Set name="retainDays">90</Set>
          <Set name="append">true</Set>
          <Set name="extended">false</Set>
          <Set name="LogTimeZone">EST</Set>
         </New>
      </Set>
    </Ref>