public int getHttpSessionInactiveTimeout() {
    return Integer.parseInt(getProperty(SERVER_HTTP_SESSION_INACTIVE_TIMEOUT));
  }
Gets the inactivity timeout value, in seconds, for sessions created in
Jetty by Spring Security. Without this timeout value, each request to the
REST APIs will create new sessions that are never reaped since their
default time is -1.

@return the time value or {@code 1800} seconds for default.
ambari-server/src/main/java/org/apache/ambari/server/configuration/Configuration.java