import { DeepstreamServices, DeepstreamConfig, ClusterRegistry, DeepstreamPlugin } from '@deepstream/types';
/**
 * This class maintains a list of all nodes that are
 * currently present within the cluster.
 *
 * It provides status messages on a predefined interval
 * and keeps track of incoming status messages.
 */
export declare class DistributedClusterRegistry extends DeepstreamPlugin implements ClusterRegistry {
    private pluginOptions;
    private services;
    private config;
    description: string;
    private inCluster;
    private nodes;
    private leaderScore;
    private publishInterval;
    private checkInterval;
    private role;
    private emitter;
    /**
     * Creates the class, initialises all intervals and publishes the
     * initial status message that notifies other nodes within this
     * cluster of its presence.
     */
    constructor(pluginOptions: any, services: Readonly<DeepstreamServices>, config: Readonly<DeepstreamConfig>);
    init(): void;
    close(): Promise<void>;
    onServerAdded(callback: (serverName: string) => void): void;
    onServerRemoved(callback: (serverName: string) => void): void;
    /**
     * Returns the serverNames of all nodes currently present within the cluster
     */
    getAll(): string[];
    /**
     * Returns true if this node is the cluster leader
     */
    isLeader(): boolean;
    /**
     * Returns the name of the current leader
     */
    getLeader(): string;
    /**
     * Distributes incoming messages on the cluster topic
     */
    private onMessage;
    /**
     * Called on an interval defined by clusterActiveCheckInterval to check if all nodes
     * within the cluster are still alive.
     *
     * Being alive is defined as having received a status message from that node less than
     * <clusterNodeInactiveTimeout> milliseconds ago.
     */
    private checkNodes;
    /**
     * Updates the status of a node with incoming status data and resets its lastStatusTime.
     *
     * If the remote node doesn't exist yet, it is added and an add event is emitted / logged
     */
    private updateNode;
    /**
     * Removes a remote node from this registry if it exists.
     * Logs/emits remove
     */
    private removeNode;
    /**
     * Publishes this node's status on the message bus
     */
    private publishStatus;
    /**
     * Prompts this node to leave the cluster, either as a result of a server.close()
     * call or due to the process exiting.
     * This sends out a leave message to all other nodes and destroys this class.
     */
    private leaveCluster;
}