@Inject
  void init() {
    requestId = stageDAO.getLastRequestId();
  }
Cache for auditlog. It stores a {@link RequestDetails} object for every requests.
{@link RequestDetails} contains the previous status of the request and a map for tasks.
A task has a {@link RequestDetails.Component} key and the value of that is the previous status of the task.
{@link RequestDetails.Component} contains the component name and the host name
ambari-server/src/main/java/org/apache/ambari/server/actionmanager/ActionDBAccessorImpl.java