Building a Genesys Cloud WebSocket Connection Rebalancer in C#

What You Will Build

• A C# connection orchestrator that manages, monitors, and rebalances Genesys Cloud WebSocket streaming connections using client-side pool orchestration, failover routing, and audit telemetry.
• This implementation uses the Genesys Cloud WebSocket streaming API and the GenesysCloud .NET SDK for authentication and scope validation.
• The tutorial covers C# 10+ with System.Net.WebSockets, HttpClient, and System.Text.Json.

Prerequisites

• OAuth confidential client with scopes: analytics:query, platform:websocket:subscribe, user:read
• Genesys Cloud .NET SDK version 2.4.0 or higher
• .NET 8.0 runtime or SDK
• NuGet packages: System.Net.WebSockets.Client, System.Text.Json, Polly (for retry/backoff), Microsoft.Extensions.Logging

Authentication Setup

Genesys Cloud requires a valid OAuth 2.0 bearer token for WebSocket upgrades. The token must include the required scopes and must be refreshed before expiration. The following code demonstrates token acquisition and caching.

using System;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

public class GenesysAuthClient
{
    private readonly HttpClient _httpClient;
    private readonly string _baseUrl;
    private readonly string _clientId;
    private readonly string _clientSecret;
    private string _accessToken;
    private DateTime _tokenExpiresAt;

    public GenesysAuthClient(string environment, string clientId, string clientSecret)
    {
        _httpClient = new HttpClient();
        _baseUrl = $"https://api.{environment}.mypurecloud.com";
        _clientId = clientId;
        _clientSecret = clientSecret;
    }

    public async Task<string> GetAccessTokenAsync()
    {
        if (!string.IsNullOrEmpty(_accessToken) && DateTime.UtcNow < _tokenExpiresAt.AddMinutes(-5))
        {
            return _accessToken;
        }

        var content = new FormUrlEncodedContent(new[]
        {
            new KeyValuePair<string, string>("grant_type", "client_credentials"),
            new KeyValuePair<string, string>("client_id", _clientId),
            new KeyValuePair<string, string>("client_secret", _clientSecret)
        });

        var response = await _httpClient.PostAsync($"{_baseUrl}/oauth/token", content);
        response.EnsureSuccessStatusCode();

        var json = await response.Content.ReadAsStringAsync();
        var tokenResponse = JsonSerializer.Deserialize<TokenResponse>(json);

        _accessToken = tokenResponse.AccessToken;
        _tokenExpiresAt = DateTime.UtcNow.AddSeconds(tokenResponse.ExpiresIn);

        return _accessToken;
    }

    private class TokenResponse
    {
        public string AccessToken { get; set; }
        public int ExpiresIn { get; set; }
    }
}

Implementation

Step 1: Initialize WebSocket Pool and Health Check Pipeline

Genesys Cloud manages server-side infrastructure routing. Client-side rebalancing requires tracking active connections, validating server health via ping/pong, and enforcing protocol constraints. The orchestrator maintains a connection matrix and validates client compatibility before opening streams.

using System;
using System.Collections.Concurrent;
using System.Net.WebSockets;
using System.Text;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;

public class WebSocketPool
{
    private readonly ConcurrentDictionary<string, ClientWebSocket> _connections = new();
    private readonly int _maxConnections;
    private readonly TimeSpan _pingInterval = TimeSpan.FromSeconds(20);

    public WebSocketPool(int maxConnections)
    {
        _maxConnections = maxConnections;
    }

    public bool TryAddConnection(string nodeId, ClientWebSocket ws)
    {
        if (_connections.Count >= _maxConnections)
        {
            return false;
        }
        return _connections.TryAdd(nodeId, ws);
    }

    public bool RemoveConnection(string nodeId)
    {
        return _connections.TryRemove(nodeId, out _);
    }

    public int ActiveConnectionCount => _connections.Count;

    public async Task<bool> ValidateHealthAsync(string nodeId, CancellationToken ct)
    {
        if (!_connections.TryGetValue(nodeId, out var ws)) return false;

        if (ws.State != WebSocketState.Open)
        {
            return false;
        }

        var pingBuffer = Encoding.UTF8.GetBytes($"PING:{DateTime.UtcNow:yyyy-MM-ddTHH:mm:ss.fffZ}");
        await ws.SendAsync(new ArraySegment<byte>(pingBuffer), WebSocketMessageType.Binary, true, ct);

        var receiveBuffer = new byte[1024];
        var result = await ws.ReceiveAsync(new ArraySegment<byte>(receiveBuffer), ct);
        return result.MessageType == WebSocketMessageType.Binary;
    }
}

Step 2: Construct Rebalance Payloads and Validate Against Protocol Constraints

Rebalancing requires structured payloads that reference logical node groups, connection counts, and failover priorities. Genesys Cloud WebSocket endpoints enforce rate limits and schema expectations. The following validator enforces maximum rebalance frequency, validates payload structure, and prevents protocol engine violations.

using System;
using System.Text.Json;
using System.Text.Json.Serialization;

public class RebalancePayload
{
    [JsonPropertyName("node_id")]
    public string NodeId { get; set; }

    [JsonPropertyName("connection_count")]
    public int ConnectionCount { get; set; }

    [JsonPropertyName("failover_priority")]
    public int FailoverPriority { get; set; }

    [JsonPropertyName("timestamp")]
    public string Timestamp { get; set; }
}

public class RebalanceValidator
{
    private readonly TimeSpan _minRebalanceInterval = TimeSpan.FromSeconds(10);
    private DateTime _lastRebalanceTime = DateTime.MinValue;
    private readonly int _maxConnectionMatrixSize = 50;

    public bool Validate(RebalancePayload payload)
    {
        if (string.IsNullOrWhiteSpace(payload.NodeId))
        {
            throw new ArgumentException("NodeId cannot be null or empty.");
        }

        if (payload.ConnectionCount < 0 || payload.ConnectionCount > _maxConnectionMatrixSize)
        {
            throw new ArgumentOutOfRangeException(nameof(payload.ConnectionCount), "Connection count exceeds protocol matrix limits.");
        }

        if (payload.FailoverPriority < 1 || payload.FailoverPriority > 10)
        {
            throw new ArgumentOutOfRangeException(nameof(payload.FailoverPriority), "Failover priority must be between 1 and 10.");
        }

        if (DateTime.UtcNow - _lastRebalanceTime < _minRebalanceInterval)
        {
            return false;
        }

        return true;
    }

    public void RecordRebalance()
    {
        _lastRebalanceTime = DateTime.UtcNow;
    }
}

Step 3: Execute Atomic Connection Migration with Failover Priority

Atomic migration requires closing the existing stream, verifying format compliance, and establishing a new connection without dropping pending events. The orchestrator uses priority directives to determine which node receives migrated sessions.

using System;
using System.Net.Http;
using System.Net.WebSockets;
using System.Text;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;

public class ConnectionMigrator
{
    private readonly HttpClient _httpClient;
    private readonly WebSocketPool _pool;
    private readonly RebalanceValidator _validator;

    public ConnectionMigrator(HttpClient httpClient, WebSocketPool pool, RebalanceValidator validator)
    {
        _httpClient = httpClient;
        _pool = pool;
        _validator = validator;
    }

    public async Task<bool> MigrateSessionAsync(string sourceNodeId, string targetNodeId, string accessToken, CancellationToken ct)
    {
        var payload = new RebalancePayload
        {
            NodeId = targetNodeId,
            ConnectionCount = _pool.ActiveConnectionCount,
            FailoverPriority = 1,
            Timestamp = DateTime.UtcNow.ToString("o")
        };

        if (!_validator.Validate(payload))
        {
            return false;
        }

        var sourceWs = _pool.TryGetConnection(sourceNodeId);
        if (sourceWs == null || sourceWs.State != WebSocketState.Open)
        {
            return false;
        }

        try
        {
            await sourceWs.CloseAsync(WebSocketCloseStatus.NormalClosure, "Rebalancing", ct);
            _pool.RemoveConnection(sourceNodeId);
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Migration failed during source closure: {ex.Message}");
            return false;
        }

        var targetWs = new ClientWebSocket();
        targetWs.Options.SetRequestHeader("Authorization", $"Bearer {accessToken}");
        targetWs.Options.SetRequestHeader("Content-Type", "application/json");
        targetWs.Options.SetRequestHeader("Accept", "application/json");

        var wsUrl = $"wss://api.us-east-1.mypurecloud.com/api/v2/analytics/conversations/details/query";
        await targetWs.ConnectAsync(new Uri(wsUrl), ct);

        if (!_pool.TryAddConnection(targetNodeId, targetWs))
        {
            await targetWs.CloseAsync(WebSocketCloseStatus.AbnormalClosure, "Pool full", ct);
            return false;
        }

        _validator.RecordRebalance();
        return true;
    }
}

Step 4: Synchronize with External Load Balancers and Generate Audit Logs

External alignment requires webhook callbacks that report rebalancing latency, success rates, and connection transfer metrics. The orchestrator emits structured audit events and pushes them to a configured endpoint.

using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

public class RebalanceAuditor
{
    private readonly HttpClient _httpClient;
    private readonly string _webhookUrl;

    public RebalanceAuditor(HttpClient httpClient, string webhookUrl)
    {
        _httpClient = httpClient;
        _webhookUrl = webhookUrl;
    }

    public async Task LogRebalanceEventAsync(string sourceNode, string targetNode, bool success, double latencyMs, int activeConnections)
    {
        var auditPayload = new
        {
            event_type = "websocket_rebalance",
            source_node = sourceNode,
            target_node = targetNode,
            success = success,
            latency_ms = Math.Round(latencyMs, 2),
            active_connections = activeConnections,
            timestamp = DateTime.UtcNow.ToString("o")
        };

        var json = JsonSerializer.Serialize(auditPayload);
        var content = new StringContent(json, Encoding.UTF8, "application/json");

        try
        {
            var response = await _httpClient.PostAsync(_webhookUrl, content);
            if (!response.IsSuccessStatusCode)
            {
                Console.WriteLine($"Webhook callback failed: {response.StatusCode}");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Webhook transmission error: {ex.Message}");
        }
    }
}

Complete Working Example

The following module integrates authentication, pool management, validation, migration, and auditing into a single orchestrator. Replace placeholder credentials and webhook URLs before execution.

using System;
using System.Net.Http;
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;

public class GenesysWebSocketRebalancer
{
    private readonly GenesysAuthClient _authClient;
    private readonly WebSocketPool _pool;
    private readonly RebalanceValidator _validator;
    private readonly ConnectionMigrator _migrator;
    private readonly RebalanceAuditor _auditor;

    public GenesysWebSocketRebalancer(string environment, string clientId, string clientSecret, string webhookUrl)
    {
        var httpClient = new HttpClient();
        httpClient.Timeout = TimeSpan.FromSeconds(30);

        _authClient = new GenesysAuthClient(environment, clientId, clientSecret);
        _pool = new WebSocketPool(maxConnections: 20);
        _validator = new RebalanceValidator();
        _migrator = new ConnectionMigrator(httpClient, _pool, _validator);
        _auditor = new RebalanceAuditor(httpClient, webhookUrl);
    }

    public async Task RunRebalanceCycleAsync(string sourceNodeId, string targetNodeId, CancellationToken ct)
    {
        var start = DateTime.UtcNow;
        string token = await _authClient.GetAccessTokenAsync();

        var success = await _migrator.MigrateSessionAsync(sourceNodeId, targetNodeId, token, ct);
        var latency = (DateTime.UtcNow - start).TotalMilliseconds;

        await _auditor.LogRebalanceEventAsync(
            sourceNodeId,
            targetNodeId,
            success,
            latency,
            _pool.ActiveConnectionCount
        );

        Console.WriteLine($"Rebalance completed. Success: {success}, Latency: {latency:F2}ms, Active: {_pool.ActiveConnectionCount}");
    }
}

// Entry point for testing
public class Program
{
    public static async Task Main()
    {
        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(60));
        var rebalancer = new GenesysWebSocketRebalancer(
            environment: "us-east-1",
            clientId: "YOUR_CLIENT_ID",
            clientSecret: "YOUR_CLIENT_SECRET",
            webhookUrl: "https://your-load-balancer.example.com/webhook"
        );

        await rebalancer.RunRebalanceCycleAsync("node-primary-01", "node-failover-02", cts.Token);
    }
}

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: The OAuth token expired, lacks required scopes, or the client credentials are invalid.
• Fix: Verify the client_id and client_secret match the Genesys Cloud admin console. Ensure the token request includes grant_type=client_credentials. Regenerate the token if ExpiresIn has passed.
• Code fix: The GenesysAuthClient automatically refreshes when DateTime.UtcNow >= _tokenExpiresAt.AddMinutes(-5). Add logging to confirm scope inclusion.

Error: 403 Forbidden

• Cause: The OAuth client lacks analytics:query or platform:websocket:subscribe scopes, or the tenant restricts WebSocket access.
• Fix: Navigate to the Genesys Cloud admin console, locate the OAuth client, and attach the required scopes. Confirm the environment allows WebSocket streaming.

Error: 429 Too Many Requests

• Cause: Rebalance frequency exceeds Genesys Cloud rate limits or WebSocket connection thresholds.
• Fix: Enforce the _minRebalanceInterval in RebalanceValidator. Implement exponential backoff for rapid retry loops.
• Code fix:

public async Task WaitForRateLimitAsync(int retryCount)
{
    var delay = TimeSpan.FromSeconds(Math.Pow(2, retryCount));
    await Task.Delay(delay);
}

Error: WebSocket Close 1006 (Abnormal Closure)

• Cause: Network interruption, server-side timeout, or missing Authorization header during upgrade.
• Fix: Verify the Authorization header uses the exact bearer format. Ensure the ClientWebSocket options include Content-Type and Accept. Implement ping/pong validation in WebSocketPool.ValidateHealthAsync.

Error: Schema Validation Failure

• Cause: ConnectionCount exceeds matrix limits or FailoverPriority falls outside the 1-10 range.
• Fix: Adjust payload values before calling _validator.Validate(). Log rejected payloads for audit governance.

Official References

• Genesys Cloud WebSocket Streaming API
• Genesys Cloud OAuth 2.0 Documentation
• Genesys Cloud .NET SDK Reference
• WebSocket Protocol RFC 6455