/**
 * Leader election for Sidekiq processes.
 *
 * Follows Sidekiq Enterprise's approach:
 * - Leaders refresh every 15 seconds
 * - Followers check/attempt acquisition every 60 seconds
 * - Redis is the source of truth (no Raft/Paxos)
 * - 20 second TTL on leader key for automatic failover
 */
import type { Config } from "./config.js";
export interface LeaderElectorOptions {
    /** Leader refresh interval in milliseconds (default: 15000) */
    refreshInterval?: number;
    /** Follower check interval in milliseconds (default: 60000) */
    checkInterval?: number;
    /** Leader key TTL in seconds (default: 20) */
    ttl?: number;
    /** Override process identity (default: hostname:pid) */
    identity?: string;
}
export declare class LeaderElector {
    private readonly config;
    private readonly identity;
    private readonly refreshInterval;
    private readonly checkInterval;
    private readonly ttl;
    private redis?;
    private isLeader;
    private running;
    private loopPromise?;
    private stopController?;
    constructor(config: Config, options?: LeaderElectorOptions);
    /**
     * Start the leader election loop.
     */
    start(): Promise<void>;
    /**
     * Stop the leader election loop and release leadership if held.
     */
    stop(): Promise<void>;
    /**
     * Returns true if this process is currently the leader.
     */
    leader(): boolean;
    /**
     * Get the identity of the current leader (may be another process).
     */
    currentLeader(): Promise<string | null>;
    /**
     * Try to acquire leadership. Returns true if successful.
     */
    private tryAcquire;
    /**
     * Refresh leadership (extend TTL). Returns true if successful.
     */
    private tryRefresh;
    /**
     * Background loop for leader election.
     */
    private leaderLoop;
}
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