amberjs 1.16.1

// Distributed Coordinator
// Coordinates distributed consensus and task execution across edge nodes

use crate::edge::{EdgeNode, NodeId, Task};
use serde::{Deserialize, Serialize};
use std::collections::BTreeMap;
use std::sync::{Arc, Mutex, RwLock};
use tokio::time::{TokioDuration, TokioInstant};
use anyhow::{Result, Error};
use std::time::{Duration, Instant};
use std::collections::HashMap;
use std::time::SystemTime;

/// Distributed coordinator
#[derive(Debug)]
pub struct DistributedCoordinator {
    consensus: Arc<ConsensusAlgorithm>,
    node_manager: Arc<super::node_manager::EdgeNodeManager>,
    active_proposals: Arc<RwLock<HashMap<String, Proposal>>>,
}
/// Consensus algorithm
#[derive(Debug)]
pub struct ConsensusAlgorithm {
    algorithm_type: ConsensusType,
    quorum_size: usize,
    timeout_ms: u64,
}
/// Proposal for consensus
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Proposal {
    pub id: String,
    pub proposer_id: NodeId,
    pub operation: Operation,
    pub timestamp: std::time::SystemTime,
    pub votes: Vec<Vote>,
}
/// Operation to be executed
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum Operation {
    TaskExecution(Task),
    NodeRegistration(EdgeNode),
    NodeDeregistration(NodeId),
    LoadBalancing,
}
/// Vote in consensus
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Vote {
    pub node_id: NodeId,
    pub proposal_id: String,
    pub vote: VoteType,
}
/// Vote type
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum VoteType {
    Accept,
    Reject,
}
/// Consensus result
#[derive(Debug, Clone)]
pub struct ConsensusResult {
    pub proposal_id: String,
    pub consensus_reached: bool,
    pub votes_for: usize,
    pub votes_against: usize,
    pub execution_time_ms: u64,
}
/// Task coordination result
#[derive(Debug, Clone)]
pub struct CoordinationResult {
    pub task_id: String,
    pub coordinator_node: NodeId,
    pub assigned_nodes: Vec<NodeId>,
    pub estimated_completion_ms: u64,
}
/// Failure detector
#[derive(Debug)]
pub struct FailureDetector {
    check_interval: Duration,
    failure_threshold: u32,
}
/// Auto recoverer
#[derive(Debug)]
pub struct AutoRecoverer {
    recovery_strategies: Vec<RecoveryStrategy>,
}
/// Failure information
#[derive(Debug, Clone)]
pub struct Failure {
    pub node_id: NodeId,
    pub failure_type: FailureType,
    pub timestamp: std::time::SystemTime,
    pub severity: FailureSeverity,
}
/// Failure type
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum FailureType {
    NodeDown,
    NetworkPartition,
    ResourceExhaustion,
    SlowResponse,
    ErrorRate,
}
/// Failure severity
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum FailureSeverity {
    Low,
    Medium,
    High,
    Critical,
}
/// Recovery result
#[derive(Debug, Clone)]
pub struct RecoveryResult {
    pub failure_id: String,
    pub recovery_successful: bool,
    pub recovery_time_ms: u64,
    pub actions_taken: Vec<String>,
}
/// Recovery strategy
#[derive(Debug, Clone)]
pub struct RecoveryStrategy {
    pub name: String,
    pub applicable_failures: Vec<FailureType>,
    pub action: RecoveryAction,
}
/// Recovery action
#[derive(Debug, Clone)]
pub enum RecoveryAction {
    RestartNode,
    RedistributeTasks,
    IncreaseResources,
    SwitchToBackup,
}
/// Consensus types
#[derive(Debug, Clone)]
pub enum ConsensusType {
    Raft,
    PBFT,
    SimpleMajority,
}
/// Node status for coordinator
#[derive(Debug, Clone)]
pub struct NodeStatus {
    pub node_id: NodeId,
    pub is_healthy: bool,
    pub last_heartbeat: std::time::SystemTime,
    pub current_load: f64,
}
impl DistributedCoordinator {
    /// Create a new distributed coordinator
    pub async fn new(node_manager: Arc<super::node_manager::EdgeNodeManager>) -> Result<Self> {
        let coordinator: _ = DistributedCoordinator {
            consensus: Arc::new(Mutex::new(ConsensusAlgorithm::new(ConsensusType::SimpleMajority, 3, 5000)))
            node_manager,
            active_proposals: Arc::new(Mutex::new(HashMap::new()))
        };
        println!("Distributed coordinator initialized");
        Ok(coordinator)
    }
    /// Reach consensus on a proposal
    pub async fn reach_consensus(&self, proposal: &Proposal) -> Result<ConsensusResult> {
        let start: _ = Instant::now();
        println!("Starting consensus for proposal {}", proposal.id);
        // Add to active proposals
        {
            let mut active = self.active_proposals.write().await;
            active.insert(proposal.id.clone(), proposal.clone());
        }
        // Get all healthy nodes
        let healthy_nodes: _ = self.get_healthy_nodes().await?;
        // Request votes from nodes
        let votes: _ = self.collect_votes(proposal, &healthy_nodes).await?;
        // Count votes
        let votes_for: _ = votes.iter().filter(|v| v.vote == VoteType::Accept).count();
        let votes_against: _ = votes.len() - votes_for;
        let consensus_reached: _ = votes_for > votes_against;
        let elapsed: _ = start.elapsed();
        println!("Consensus {} for proposal {} in {}ms ({} for, {} against)",
                 if consensus_reached { "reached" } else { "failed" },
                 proposal.id, elapsed.as_millis(), votes_for, votes_against);
        // Remove from active proposals
        {
            let mut active = self.active_proposals.write().await;
            active.remove(&proposal.id);
        }
        Ok(ConsensusResult {
            proposal_id: proposal.id.clone(),
            consensus_reached,
            votes_for,
            votes_against,
            execution_time_ms: elapsed.as_millis() as u64,
        })
    }
    /// Coordinate task execution
    pub async fn coordinate_task(&self, task: &Task) -> Result<CoordinationResult> {
        let start: _ = Instant::now();
        println!(" Coordinating task {}", task.id);
        // Get optimal nodes
        let nodes: _ = self.node_manager.discover_nodes().await?;
        let selected_nodes: _ = self.select_nodes_for_task(task, &nodes).await?;
        // Create proposal for task execution
        let proposal: _ = Proposal {
            id: format!("task-{}", task.id),
            proposer_id: NodeId("coordinator".to_string()),
            operation: Operation::TaskExecution(task.clone()),
            timestamp: std::time::SystemTime::now(),
            votes: Vec::new(),
        };
        // Reach consensus
        let consensus: _ = self.reach_consensus(&proposal).await?;
        let elapsed: _ = start.elapsed();
        let result: _ = CoordinationResult {
            task_id: task.id.clone(),
            coordinator_node: NodeId("coordinator".to_string()),
            assigned_nodes: selected_nodes,
            estimated_completion_ms: elapsed.as_millis() as u64,
        };
        println!("Task coordination completed in {}ms", result.estimated_completion_ms);
        Ok(result)
    }
    /// Get all healthy nodes
    async fn get_healthy_nodes(&self) -> Result<Vec<NodeId> {
        let nodes: _ = self.node_manager.discover_nodes().await?;
        let healthy_nodes: Vec<NodeId> = nodes.into_iter().map(|n| n.id).collect();
        Ok(healthy_nodes)
    }
    /// Collect votes from nodes
    async fn collect_votes(&self, proposal: &Proposal, nodes: &[NodeId]) -> Result<Vec<Vote> {
        let mut votes = Vec::new();
        // Simulate voting from each node
        for node_id in nodes {
            tokio::time::sleep(Duration::from_millis(2)).await;
            // Simple voting logic: accept if load is low
            let vote: _ = if node_id.0.contains("low") {
                VoteType::Accept
            } else {
                VoteType::Accept // Most nodes accept for demo
            };
            votes.push(Vote {
                node_id: node_id.clone(),
                proposal_id: proposal.id.clone(),
                vote,
            });
        }
        Ok(votes)
    }
    /// Select nodes for a task
    async fn select_nodes_for_task(&self, task: &Task, nodes: &[EdgeNode]) -> Result<Vec<NodeId> {
        // Simple selection: pick first few nodes
        let selected: Vec<NodeId> = nodes.iter().take(3).map(|n| n.id.clone()).collect();
        Ok(selected)
    }
    /// Get active proposals
    pub async fn get_active_proposals(&self) -> Vec<Proposal> {
        let active: _ = self.active_proposals.read().await;
        active.values().cloned().collect()
    }
}
impl ConsensusAlgorithm {
    /// Create a new consensus algorithm
    pub fn new(algorithm_type: ConsensusType, quorum_size: usize, timeout_ms: u64) -> Self {
        ConsensusAlgorithm {
            algorithm_type,
            quorum_size,
            timeout_ms,
        }
    }
    /// Validate proposal
    pub fn validate_proposal(&self, proposal: &Proposal) -> Result<()> {
        // Basic validation
        if proposal.id.is_empty() {
            return Err(anyhow::anyhow!("Proposal ID cannot be empty"));
        }
        if proposal.operation == Operation::TaskExecution(_) && proposal.id.starts_with("task-") {
            return Ok(());
        }
        Err(anyhow::anyhow!("Invalid proposal"))
    }
}
impl FailureDetector {
    /// Create a new failure detector
    pub async fn new() -> Result<Self> {
        let detector: _ = FailureDetector {
            check_interval: Duration::from_secs(30),
            failure_threshold: 3,
        };
        println!("Failure detector initialized");
        Ok(detector)
    }
    /// Detect failures
    pub async fn detect_failures(&self) -> Result<Vec<Failure> {
        // Simulate failure detection
        tokio::time::sleep(Duration::from_millis(10)).await;
        Ok(Vec::new())
    }
    /// Check if a node has failed
    pub async fn check_node_health(&self, node_id: &NodeId) -> Result<bool> {
        // Simulate health check
        tokio::time::sleep(Duration::from_millis(5)).await;
        // 90% chance of being healthy
        Ok(fastrand::f32() > 0.1)
    }
}
impl AutoRecoverer {
    /// Create a new auto recoverer
    pub async fn new() -> Result<Self> {
        let strategies: _ = vec![
            RecoveryStrategy {
                name: "restart_node".to_string(),
                applicable_failures: vec![FailureType::NodeDown],
                action: RecoveryAction::RestartNode,
            },
            RecoveryStrategy {
                name: "redistribute_tasks".to_string(),
                applicable_failures: vec![FailureType::ResourceExhaustion, FailureType::SlowResponse],
                action: RecoveryAction::RedistributeTasks,
            },
        ];
        let recoverer: _ = AutoRecoverer {
            recovery_strategies: strategies,
        };
        println!("Auto recoverer initialized with {} strategies", strategies.len());
        Ok(recoverer)
    }
    /// Recover from failure
    pub async fn recover_from_failure(&self, failure: &Failure) -> Result<RecoveryResult> {
        let start: _ = Instant::now();
        println!("Attempting to recover from failure: {:?}", failure.failure_type);
        // Find applicable strategy
        let strategy: _ = self.recovery_strategies
            .iter()
            .find(|s| s.applicable_failures.contains(&failure.failure_type))
            .cloned()
            .unwrap_or_else(|| RecoveryStrategy {
                name: "default".to_string(),
                applicable_failures: vec![],
                action: RecoveryAction::RestartNode,
            });
        // Execute recovery action
        let actions_taken: _ = self.execute_recovery_action(&strategy, failure).await?;
        let elapsed: _ = start.elapsed();
        let result: _ = RecoveryResult {
            failure_id: format!("{:?}-{}", failure.failure_type, failure.node_id.0),
            recovery_successful: !actions_taken.is_empty(),
            recovery_time_ms: elapsed.as_millis() as u64,
            actions_taken,
        };
        println!("Recovery {} in {}ms",
                 if result.recovery_successful { "successful" } else { "failed" },
                 result.recovery_time_ms);
        Ok(result)
    }
    /// Execute recovery action
    async fn execute_recovery_action(&self, strategy: &RecoveryStrategy, failure: &Failure) -> Result<Vec<String> {
        let mut actions = Vec::new();
        match &strategy.action {
            RecoveryAction::RestartNode => {
                tokio::time::sleep(Duration::from_millis(100)).await;
                actions.push(format!("Restarted node {}", failure.node_id.0));
            }
            RecoveryAction::RedistributeTasks => {
                tokio::time::sleep(Duration::from_millis(50)).await;
                actions.push("Redistributed tasks to other nodes".to_string());
            }
            RecoveryAction::IncreaseResources => {
                tokio::time::sleep(Duration::from_millis(30)).await;
                actions.push("Increased resource allocation".to_string());
            }
            RecoveryAction::SwitchToBackup => {
                tokio::time::sleep(Duration::from_millis(20)).await;
                actions.push("Switched to backup node".to_string());
            }
        }
        Ok(actions)
    }
}