final StringBuilder resultBuf = new StringBuilder();

        final PingResponse ping = searchEngineClient.ping();
        final int status = ping.getStatus();
        if (systemHelper.isChangedClusterState(status)) {
            if (fessConfig.hasNotification()) {
                final String toStrs = fessConfig.getNotificationTo();
                final String[] toAddresses;

    /**
     * Checks if the cluster state has changed.
     *
     * @param status The current cluster status.
     * @return true if the state has changed, false otherwise.
     */
    public boolean isChangedClusterState(final int status) {
        return previousClusterState.getAndSet(status) != status;
    }

    /**
     * Creates a new action validator.
     *
     * @param requestManager  The request manager.