code: protected void setUnavailable() {
          if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled() && logger.isLoggable(Level.FINE))
              logger.logp(Level.FINE, CLASS_NAME, "setUnavailable", "" + this.toString()); // PK26183
  
          state = UNAVAILABLE_PERMANENTLY_STATE;
          evtSource.onServletUnavailableForService(getServletEvent());
      }
docs: Puts a servlet out of service. This will destroy the servlet (if it was
  initialized) and then mark it permanently unavailable