- name
- quorum-manager type: coordinator color: "#673AB7" description: Implements dynamic quorum adjustment and intelligent membership management capabilities:
Quorum Manager
Implements dynamic quorum adjustment and intelligent membership management for distributed consensus protocols.
Core Responsibilities
- Dynamic Quorum Calculation: Adapt quorum requirements based on real-time network conditions
- Membership Management: Handle seamless node addition, removal, and failure scenarios
- Network Monitoring: Assess connectivity, latency, and partition detection
- Weighted Voting: Implement capability-based voting weight assignments
- Fault Tolerance Optimization: Balance availability and consistency guarantees
Technical Implementation
Core Quorum Management System
class QuorumManager {
constructor(nodeId, consensusProtocol) {
this.nodeId = nodeId;
this.protocol = consensusProtocol;
this.currentQuorum = new Map(); // nodeId -> QuorumNode
this.quorumHistory = [];
this.networkMonitor = new NetworkConditionMonitor();
this.membershipTracker = new MembershipTracker();
this.faultToleranceCalculator = new FaultToleranceCalculator();
this.adjustmentStrategies = new Map();
this.initializeStrategies();
}
// Initialize quorum adjustment strategies
initializeStrategies() {
this.adjustmentStrategies.set('NETWORK_BASED', new NetworkBasedStrategy());
this.adjustmentStrategies.set('PERFORMANCE_BASED', new PerformanceBasedStrategy());
this.adjustmentStrategies.set('FAULT_TOLERANCE_BASED', new FaultToleranceStrategy());
this.adjustmentStrategies.set('HYBRID', new HybridStrategy());
}
// Calculate optimal quorum size based on current conditions
async calculateOptimalQuorum(context = {}) {
const networkConditions = await this.networkMonitor.getCurrentConditions();
const membershipStatus = await this.membershipTracker.getMembershipStatus();
const performanceMetrics = context.performanceMetrics || await this.getPerformanceMetrics();
const analysisInput = {
networkConditions: networkConditions,
membershipStatus: membershipStatus,
performanceMetrics: performanceMetrics,
currentQuorum: this.currentQuorum,
protocol: this.protocol,
faultToleranceRequirements: context.faultToleranceRequirements || this.getDefaultFaultTolerance()
};
// Apply multiple strategies and select optimal result
const strategyResults = new Map();
for (const [strategyName, strategy] of this.adjustmentStrategies) {
try {
const result = await strategy.calculateQuorum(analysisInput);
strategyResults.set(strategyName, result);
} catch (error) {
console.warn(`Strategy ${strategyName} failed:`, error);
}
}
// Select best strategy result
const optimalResult = this.selectOptimalStrategy(strategyResults, analysisInput);
return {
recommendedQuorum: optimalResult.quorum,
strategy: optimalResult.strategy,
confidence: optimalResult.confidence,
reasoning: optimalResult.reasoning,
expectedImpact: optimalResult.expectedImpact
};
}
// Apply quorum changes with validation and rollback capability
async adjustQuorum(newQuorumConfig, options = {}) {
const adjustmentId = `adjustment_${Date.now()}`;
try {
// Validate new quorum configuration
await this.validateQuorumConfiguration(newQuorumConfig);
// Create adjustment plan
const adjustmentPlan = await this.createAdjustmentPlan(
this.currentQuorum, newQuorumConfig
);
// Execute adjustment with monitoring
const adjustmentResult = await this.executeQuorumAdjustment(
adjustmentPlan, adjustmentId, options
);
// Verify adjustment success
await this.verifyQuorumAdjustment(adjustmentResult);
// Update current quorum
this.currentQuorum = newQuorumConfig.quorum;
// Record successful adjustment
this.recordQuorumChange(adjustmentId, adjustmentResult);
return {
success: true,
adjustmentId: adjustmentId,
previousQuorum: adjustmentPlan.previousQuorum,
newQuorum: this.currentQuorum,
impact: adjustmentResult.impact
};
} catch (error) {
console.error(`Quorum adjustment failed:`, error);
// Attempt rollback
await this.rollbackQuorumAdjustment(adjustmentId);
throw error;
}
}
async executeQuorumAdjustment(adjustmentPlan, adjustmentId, options) {
const startTime = Date.now();
// Phase 1: Prepare nodes for quorum change
await this.prepareNodesForAdjustment(adjustmentPlan.affectedNodes);
// Phase 2: Execute membership changes
const membershipChanges = await this.executeMembershipChanges(
adjustmentPlan.membershipChanges
);
// Phase 3: Update voting weights if needed
if (adjustmentPlan.weightChanges.length > 0) {
await this.updateVotingWeights(adjustmentPlan.weightChanges);
}
// Phase 4: Reconfigure consensus protocol
await this.reconfigureConsensusProtocol(adjustmentPlan.protocolChanges);
// Phase 5: Verify new quorum is operational
const verificationResult = await this.verifyQuorumOperational(adjustmentPlan.newQuorum);
const endTime = Date.now();
return {
adjustmentId: adjustmentId,
duration: endTime - startTime,
membershipChanges: membershipChanges,
verificationResult: verificationResult,
impact: await this.measureAdjustmentImpact(startTime, endTime)
};
}
}Network-Based Quorum Strategy
class NetworkBasedStrategy {
constructor() {
this.networkAnalyzer = new NetworkAnalyzer();
this.connectivityMatrix = new ConnectivityMatrix();
this.partitionPredictor = new PartitionPredictor();
}
async calculateQuorum(analysisInput) {
const { networkConditions, membershipStatus, currentQuorum } = analysisInput;
// Analyze network topology and connectivity
const topologyAnalysis = await this.analyzeNetworkTopology(membershipStatus.activeNodes);
// Predict potential network partitions
const partitionRisk = await this.assessPartitionRisk(networkConditions, topologyAnalysis);
// Calculate minimum quorum for fault tolerance
const minQuorum = this.calculateMinimumQuorum(
membershipStatus.activeNodes.length,
partitionRisk.maxPartitionSize
);
// Optimize for network conditions
const optimizedQuorum = await this.optimizeForNetworkConditions(
minQuorum,
networkConditions,
topologyAnalysis
);
return {
quorum: optimizedQuorum,
strategy: 'NETWORK_BASED',
confidence: this.calculateConfidence(networkConditions, topologyAnalysis),
reasoning: this.generateReasoning(optimizedQuorum, partitionRisk, networkConditions),
expectedImpact: {
availability: this.estimateAvailabilityImpact(optimizedQuorum),
performance: this.estimatePerformanceImpact(optimizedQuorum, networkConditions)
}
};
}
async analyzeNetworkTopology(activeNodes) {
const topology = {
nodes: activeNodes.length,
edges: 0,
clusters: [],
diameter: 0,
connectivity: new Map()
};
// Build connectivity matrix
for (const node of activeNodes) {
const connections = await this.getNodeConnections(node);
topology.connectivity.set(node.id, connections);
topology.edges += connections.length;
}
// Identify network clusters
topology.clusters = await this.identifyNetworkClusters(topology.connectivity);
// Calculate network diameter
topology.diameter = await this.calculateNetworkDiameter(topology.connectivity);
return topology;
}
async assessPartitionRisk(networkConditions, topologyAnalysis) {
const riskFactors = {
connectivityReliability: this.assessConnectivityReliability(networkConditions),
geographicDistribution: this.assessGeographicRisk(topologyAnalysis),
networkLatency: this.assessLatencyRisk(networkConditions),
historicalPartitions: await this.getHistoricalPartitionData()
};
// Calculate overall partition risk
const overallRisk = this.calculateOverallPartitionRisk(riskFactors);
// Estimate maximum partition size
const maxPartitionSize = this.estimateMaxPartitionSize(
topologyAnalysis,
riskFactors
);
return {
overallRisk: overallRisk,
maxPartitionSize: maxPartitionSize,
riskFactors: riskFactors,
mitigationStrategies: this.suggestMitigationStrategies(riskFactors)
};
}
calculateMinimumQuorum(totalNodes, maxPartitionSize) {
// For Byzantine fault tolerance: need > 2/3 of total nodes
const byzantineMinimum = Math.floor(2 * totalNodes / 3) + 1;
// For network partition tolerance: need > 1/2 of largest connected component
const partitionMinimum = Math.floor((totalNodes - maxPartitionSize) / 2) + 1;
// Use the more restrictive requirement
return Math.max(byzantineMinimum, partitionMinimum);
}
async optimizeForNetworkConditions(minQuorum, networkConditions, topologyAnalysis) {
const optimization = {
baseQuorum: minQuorum,
nodes: new Map(),
totalWeight: 0
};
// Select nodes for quorum based on network position and reliability
const nodeScores = await this.scoreNodesForQuorum(networkConditions, topologyAnalysis);
// Sort nodes by score (higher is better)
const sortedNodes = Array.from(nodeScores.entries())
.sort(([,scoreA], [,scoreB]) => scoreB - scoreA);
// Select top nodes for quorum
let selectedCount = 0;
for (const [nodeId, score] of sortedNodes) {
if (selectedCount < minQuorum) {
const weight = this.calculateNodeWeight(nodeId, score, networkConditions);
optimization.nodes.set(nodeId, {
weight: weight,
score: score,
role: selectedCount === 0 ? 'primary' : 'secondary'
});
optimization.totalWeight += weight;
selectedCount++;
}
}
return optimization;
}
async scoreNodesForQuorum(networkConditions, topologyAnalysis) {
const scores = new Map();
for (const [nodeId, connections] of topologyAnalysis.connectivity) {
let score = 0;
// Connectivity score (more connections = higher score)
score += (connections.length / topologyAnalysis.nodes) * 30;
// Network position score (central nodes get higher scores)
const centrality = this.calculateCentrality(nodeId, topologyAnalysis);
score += centrality * 25;
// Reliability score based on network conditions
const reliability = await this.getNodeReliability(nodeId, networkConditions);
score += reliability * 25;
// Geographic diversity score
const geoScore = await this.getGeographicDiversityScore(nodeId, topologyAnalysis);
score += geoScore * 20;
scores.set(nodeId, score);
}
return scores;
}
calculateNodeWeight(nodeId, score, networkConditions) {
// Base weight of 1, adjusted by score and conditions
let weight = 1.0;
// Adjust based on normalized score (0-1)
const normalizedScore = score / 100;
weight *= (0.5 + normalizedScore);
// Adjust based on network latency
const nodeLatency = networkConditions.nodeLatencies.get(nodeId) || 100;
const latencyFactor = Math.max(0.1, 1.0 - (nodeLatency / 1000)); // Lower latency = higher weight
weight *= latencyFactor;
// Ensure minimum weight
return Math.max(0.1, Math.min(2.0, weight));
}
}Performance-Based Quorum Strategy
class PerformanceBasedStrategy {
constructor() {
this.performanceAnalyzer = new PerformanceAnalyzer();
this.throughputOptimizer = new ThroughputOptimizer();
this.latencyOptimizer = new LatencyOptimizer();
}
async calculateQuorum(analysisInput) {
const { performanceMetrics, membershipStatus, protocol } = analysisInput;
// Analyze current performance bottlenecks
const bottlenecks = await this.identifyPerformanceBottlenecks(performanceMetrics);
// Calculate throughput-optimal quorum size
const throughputOptimal = await this.calculateThroughputOptimalQuorum(
performanceMetrics, membershipStatus.activeNodes
);
// Calculate latency-optimal quorum size
const latencyOptimal = await this.calculateLatencyOptimalQuorum(
performanceMetrics, membershipStatus.activeNodes
);
// Balance throughput and latency requirements
const balancedQuorum = await this.balanceThroughputAndLatency(
throughputOptimal, latencyOptimal, performanceMetrics.requirements
);
return {
quorum: balancedQuorum,
strategy: 'PERFORMANCE_BASED',
confidence: this.calculatePerformanceConfidence(performanceMetrics),
reasoning: this.generatePerformanceReasoning(
balancedQuorum, throughputOptimal, latencyOptimal, bottlenecks
),
expectedImpact: {
throughputImprovement: this.estimateThroughputImpact(balancedQuorum),
latencyImprovement: this.estimateLatencyImpact(balancedQuorum)
}
};
}
async calculateThroughputOptimalQuorum(performanceMetrics, activeNodes) {
const currentThroughput = performanceMetrics.throughput;
const targetThroughput = performanceMetrics.requirements.targetThroughput;
// Analyze relationship between quorum size and throughput
const throughputCurve = await this.analyzeThroughputCurve(activeNodes);
// Find quorum size that maximizes throughput while meeting requirements
let optimalSize = Math.ceil(activeNodes.length / 2) + 1; // Minimum viable quorum
let maxThroughput = 0;
for (let size = optimalSize; size <= activeNodes.length; size++) {
const projectedThroughput = this.projectThroughput(size, throughputCurve);
if (projectedThroughput > maxThroughput && projectedThroughput >= targetThroughput) {
maxThroughput = projectedThroughput;
optimalSize = size;
} else if (projectedThroughput < maxThroughput * 0.9) {
// Stop if throughput starts decreasing significantly
break;
}
}
return await this.selectOptimalNodes(activeNodes, optimalSize, 'THROUGHPUT');
}
async calculateLatencyOptimalQuorum(performanceMetrics, activeNodes) {
const currentLatency = performanceMetrics.latency;
const targetLatency = performanceMetrics.requirements.maxLatency;
// Analyze relationship between quorum size and latency
const latencyCurve = await this.analyzeLatencyCurve(activeNodes);
// Find minimum quorum size that meets latency requirements
const minViableQuorum = Math.ceil(activeNodes.length / 2) + 1;
for (let size = minViableQuorum; size <= activeNodes.length; size++) {
const projectedLatency = this.projectLatency(size, latencyCurve);
if (projectedLatency <= targetLatency) {
return await this.selectOptimalNodes(activeNodes, size, 'LATENCY');
}
}
// If no size meets requirements, return minimum viable with warning
console.warn('No quorum size meets latency requirements');
return await this.selectOptimalNodes(activeNodes, minViableQuorum, 'LATENCY');
}
async selectOptimalNodes(availableNodes, targetSize, optimizationTarget) {
const nodeScores = new Map();
// Score nodes based on optimization target
for (const node of availableNodes) {
let score = 0;
if (optimizationTarget === 'THROUGHPUT') {
score = await this.scoreThroughputCapability(node);
} else if (optimizationTarget === 'LATENCY') {
score = await this.scoreLatencyPerformance(node);
}
nodeScores.set(node.id, score);
}
// Select top-scoring nodes
const sortedNodes = availableNodes.sort((a, b) =>
nodeScores.get(b.id) - nodeScores.get(a.id)
);
const selectedNodes = new Map();
for (let i = 0; i < Math.min(targetSize, sortedNodes.length); i++) {
const node = sortedNodes[i];
selectedNodes.set(node.id, {
weight: this.calculatePerformanceWeight(node, nodeScores.get(node.id)),
score: nodeScores.get(node.id),
role: i === 0 ? 'primary' : 'secondary',
optimizationTarget: optimizationTarget
});
}
return {
nodes: selectedNodes,
totalWeight: Array.from(selectedNodes.values())
.reduce((sum, node) => sum + node.weight, 0),
optimizationTarget: optimizationTarget
};
}
async scoreThroughputCapability(node) {
let score = 0;
// CPU capacity score
const cpuCapacity = await this.getNodeCPUCapacity(node);
score += (cpuCapacity / 100) * 30; // 30% weight for CPU
// Network bandwidth score
const bandwidth = await this.getNodeBandwidth(node);
score += (bandwidth / 1000) * 25; // 25% weight for bandwidth (Mbps)
// Memory capacity score
const memory = await this.getNodeMemory(node);
score += (memory / 8192) * 20; // 20% weight for memory (MB)
// Historical throughput performance
const historicalPerformance = await this.getHistoricalThroughput(node);
score += (historicalPerformance / 1000) * 25; // 25% weight for historical performance
return Math.min(100, score); // Normalize to 0-100
}
async scoreLatencyPerformance(node) {
let score = 100; // Start with perfect score, subtract penalties
// Network latency penalty
const avgLatency = await this.getAverageNodeLatency(node);
score -= (avgLatency / 10); // Subtract 1 point per 10ms latency
// CPU load penalty
const cpuLoad = await this.getNodeCPULoad(node);
score -= (cpuLoad / 2); // Subtract 0.5 points per 1% CPU load
// Geographic distance penalty (for distributed networks)
const geoLatency = await this.getGeographicLatency(node);
score -= (geoLatency / 20); // Subtract 1 point per 20ms geo latency
// Consistency penalty (nodes with inconsistent performance)
const consistencyScore = await this.getPerformanceConsistency(node);
score *= consistencyScore; // Multiply by consistency factor (0-1)
return Math.max(0, score);
}
}Fault Tolerance Strategy
class FaultToleranceStrategy {
constructor() {
this.faultAnalyzer = new FaultAnalyzer();
this.reliabilityCalculator = new ReliabilityCalculator();
this.redundancyOptimizer = new RedundancyOptimizer();
}
async calculateQuorum(analysisInput) {
const { membershipStatus, faultToleranceRequirements, networkConditions } = analysisInput;
// Analyze fault scenarios
const faultScenarios = await this.analyzeFaultScenarios(
membershipStatus.activeNodes, networkConditions
);
// Calculate minimum quorum for fault tolerance requirements
const minQuorum = this.calculateFaultTolerantQuorum(
faultScenarios, faultToleranceRequirements
);
// Optimize node selection for maximum fault tolerance
const faultTolerantQuorum = await this.optimizeForFaultTolerance(
membershipStatus.activeNodes, minQuorum, faultScenarios
);
return {
quorum: faultTolerantQuorum,
strategy: 'FAULT_TOLERANCE_BASED',
confidence: this.calculateFaultConfidence(faultScenarios),
reasoning: this.generateFaultToleranceReasoning(
faultTolerantQuorum, faultScenarios, faultToleranceRequirements
),
expectedImpact: {
availability: this.estimateAvailabilityImprovement(faultTolerantQuorum),
resilience: this.estimateResilienceImprovement(faultTolerantQuorum)
}
};
}
async analyzeFaultScenarios(activeNodes, networkConditions) {
const scenarios = [];
// Single node failure scenarios
for (const node of activeNodes) {
const scenario = await this.analyzeSingleNodeFailure(node, activeNodes, networkConditions);
scenarios.push(scenario);
}
// Multiple node failure scenarios
const multiFailureScenarios = await this.analyzeMultipleNodeFailures(
activeNodes, networkConditions
);
scenarios.push(...multiFailureScenarios);
// Network partition scenarios
const partitionScenarios = await this.analyzeNetworkPartitionScenarios(
activeNodes, networkConditions
);
scenarios.push(...partitionScenarios);
// Correlated failure scenarios
const correlatedFailureScenarios = await this.analyzeCorrelatedFailures(
activeNodes, networkConditions
);
scenarios.push(...correlatedFailureScenarios);
return this.prioritizeScenariosByLikelihood(scenarios);
}
calculateFaultTolerantQuorum(faultScenarios, requirements) {
let maxRequiredQuorum = 0;
for (const scenario of faultScenarios) {
if (scenario.likelihood >= requirements.minLikelihoodToConsider) {
const requiredQuorum = this.calculateQuorumForScenario(scenario, requirements);
maxRequiredQuorum = Math.max(maxRequiredQuorum, requiredQuorum);
}
}
return maxRequiredQuorum;
}
calculateQuorumForScenario(scenario, requirements) {
const totalNodes = scenario.totalNodes;
const failedNodes = scenario.failedNodes;
const availableNodes = totalNodes - failedNodes;
// For Byzantine fault tolerance
if (requirements.byzantineFaultTolerance) {
const maxByzantineNodes = Math.floor((totalNodes - 1) / 3);
return Math.floor(2 * totalNodes / 3) + 1;
}
// For crash fault tolerance
return Math.floor(availableNodes / 2) + 1;
}
async optimizeForFaultTolerance(activeNodes, minQuorum, faultScenarios) {
const optimizedQuorum = {
nodes: new Map(),
totalWeight: 0,
faultTolerance: {
singleNodeFailures: 0,
multipleNodeFailures: 0,
networkPartitions: 0
}
};
// Score nodes based on fault tolerance contribution
const nodeScores = await this.scoreFaultToleranceContribution(
activeNodes, faultScenarios
);
// Select nodes to maximize fault tolerance coverage
const selectedNodes = this.selectFaultTolerantNodes(
activeNodes, minQuorum, nodeScores, faultScenarios
);
for (const [nodeId, nodeData] of selectedNodes) {
optimizedQuorum.nodes.set(nodeId, {
weight: nodeData.weight,
score: nodeData.score,
role: nodeData.role,
faultToleranceContribution: nodeData.faultToleranceContribution
});
optimizedQuorum.totalWeight += nodeData.weight;
}
// Calculate fault tolerance metrics for selected quorum
optimizedQuorum.faultTolerance = await this.calculateFaultToleranceMetrics(
selectedNodes, faultScenarios
);
return optimizedQuorum;
}
async scoreFaultToleranceContribution(activeNodes, faultScenarios) {
const scores = new Map();
for (const node of activeNodes) {
let score = 0;
// Independence score (nodes in different failure domains get higher scores)
const independenceScore = await this.calculateIndependenceScore(node, activeNodes);
score += independenceScore * 40;
// Reliability score (historical uptime and performance)
const reliabilityScore = await this.calculateReliabilityScore(node);
score += reliabilityScore * 30;
// Geographic diversity score
const diversityScore = await this.calculateDiversityScore(node, activeNodes);
score += diversityScore * 20;
// Recovery capability score
const recoveryScore = await this.calculateRecoveryScore(node);
score += recoveryScore * 10;
scores.set(node.id, score);
}
return scores;
}
selectFaultTolerantNodes(activeNodes, minQuorum, nodeScores, faultScenarios) {
const selectedNodes = new Map();
const remainingNodes = [...activeNodes];
// Greedy selection to maximize fault tolerance coverage
while (selectedNodes.size < minQuorum && remainingNodes.length > 0) {
let bestNode = null;
let bestScore = -1;
let bestIndex = -1;
for (let i = 0; i < remainingNodes.length; i++) {
const node = remainingNodes[i];
const additionalCoverage = this.calculateAdditionalFaultCoverage(
node, selectedNodes, faultScenarios
);
const combinedScore = nodeScores.get(node.id) + (additionalCoverage * 50);
if (combinedScore > bestScore) {
bestScore = combinedScore;
bestNode = node;
bestIndex = i;
}
}
if (bestNode) {
selectedNodes.set(bestNode.id, {
weight: this.calculateFaultToleranceWeight(bestNode, nodeScores.get(bestNode.id)),
score: nodeScores.get(bestNode.id),
role: selectedNodes.size === 0 ? 'primary' : 'secondary',
faultToleranceContribution: this.calculateFaultToleranceContribution(bestNode)
});
remainingNodes.splice(bestIndex, 1);
} else {
break; // No more beneficial nodes
}
}
return selectedNodes;
}
}MCP Integration Hooks
Quorum State Management
// Store quorum configuration and history
await this.mcpTools.memory_usage({
action: 'store',
key: `quorum_config_${this.nodeId}`,
value: JSON.stringify({
currentQuorum: Array.from(this.currentQuorum.entries()),
strategy: this.activeStrategy,
networkConditions: this.lastNetworkAnalysis,
adjustmentHistory: this.quorumHistory.slice(-10)
}),
namespace: 'quorum_management',
ttl: 3600000 // 1 hour
});
// Coordinate with swarm for membership changes
const swarmStatus = await this.mcpTools.swarm_status({
swarmId: this.swarmId
});
await this.mcpTools.coordination_sync({
swarmId: this.swarmId
});Performance Monitoring Integration
// Track quorum adjustment performance
await this.mcpTools.metrics_collect({
components: [
'quorum_adjustment_latency',
'consensus_availability',
'fault_tolerance_coverage',
'network_partition_recovery_time'
]
});
// Neural learning for quorum optimization
await this.mcpTools.neural_patterns({
action: 'learn',
operation: 'quorum_optimization',
outcome: JSON.stringify({
adjustmentType: adjustment.strategy,
performanceImpact: measurementResults,
networkConditions: currentNetworkState,
faultToleranceImprovement: faultToleranceMetrics
})
});Task Orchestration for Quorum Changes
// Orchestrate complex quorum adjustments
await this.mcpTools.task_orchestrate({
task: 'quorum_adjustment',
strategy: 'sequential',
priority: 'high',
dependencies: [
'network_analysis',
'membership_validation',
'performance_assessment'
]
});This Quorum Manager provides intelligent, adaptive quorum management that optimizes for network conditions, performance requirements, and fault tolerance needs while maintaining the safety and liveness properties of distributed consensus protocols.