Service Lifecycle Management

<Matrix xmlns="http://schemas.matrix.com/network/2024">
    <ServiceNode Name="OrderProcessor">
        <!-- Lifecycle configuration -->
        <ServiceNode.Lifecycle>
            <LifecycleManager>
                <!-- Initialization phase -->
                <Initialization Timeout="00:00:30">
                    <Step Name="ConfigureEndpoints" Order="1" />
                    <Step Name="InitializeState" Order="2" />
                    <Step Name="RegisterService" Order="3" />
                </Initialization>

                <!-- Activation phase -->
                <Activation>
                    <Dependency Service="Database" MinVersion="2.0" />
                    <Dependency Service="MessageQueue" Required="true" />
                    <HealthCheck Path="/health" Interval="00:00:15" />
                </Activation>

                <!-- Deactivation phase -->
                <Deactivation GracePeriod="00:00:30">
                    <Step Name="StopAcceptingRequests" Order="1" />
                    <Step Name="CompleteProcessing" Order="2" />
                    <Step Name="DeregisterService" Order="3" />
                </Deactivation>
            </LifecycleManager>
        </ServiceNode.Lifecycle>
    </ServiceNode>
</Matrix>

public class ServiceLifecycleManager : CommunicationElement
{
    private readonly IServiceStateManager _stateManager;
    private readonly IServiceRegistry _registry;
    private readonly IHealthMonitor _healthMonitor;

    public async Task InitializeAsync(ServiceNode service)
    {
        try
        {
            // Execute initialization steps
            foreach (var step in GetOrderedSteps(service.Initialization))
            {
                await ExecuteLifecycleStepAsync(step);
            }

            // Verify dependencies
            await VerifyDependenciesAsync(service.Dependencies);

            // Start health monitoring
            await _healthMonitor.StartAsync(service);

            // Update service state
            await _stateManager.TransitionToAsync(ServiceState.Initialized);
        }
        catch (LifecycleException ex)
        {
            await HandleInitializationFailureAsync(ex);
            throw;
        }
    }

    public async Task ActivateAsync(ServiceNode service)
    {
        try
        {
            // Register with service discovery
            await _registry.RegisterAsync(service);

            // Start accepting requests
            await service.StartAcceptingRequestsAsync();

            // Update service state
            await _stateManager.TransitionToAsync(ServiceState.Active);
        }
        catch (ActivationException ex)
        {
            await HandleActivationFailureAsync(ex);
            throw;
        }
    }

    public async Task DeactivateAsync(ServiceNode service)
    {
        try
        {
            // Stop accepting new requests
            await service.StopAcceptingRequestsAsync();

            // Wait for in-flight requests
            await WaitForInFlightRequestsAsync(
                service.Deactivation.GracePeriod);

            // Deregister from service discovery
            await _registry.DeregisterAsync(service);

            // Update service state
            await _stateManager.TransitionToAsync(ServiceState.Inactive);
        }
        catch (DeactivationException ex)
        {
            await HandleDeactivationFailureAsync(ex);
            throw;
        }
    }
}

public class ServiceStateManager : CommunicationElement
{
    private readonly IStateStore _stateStore;
    private readonly IStateReplicator _replicator;

    public async Task TransitionToAsync(ServiceState newState)
    {
        var transition = new StateTransition(
            CurrentState,
            newState,
            DateTimeOffset.UtcNow
        );

        // Validate transition
        if (!IsValidTransition(transition))
            throw new InvalidStateTransitionException(transition);

        // Store state change
        await _stateStore.StoreTransitionAsync(transition);

        // Replicate to other nodes
        await _replicator.ReplicateAsync(transition);

        // Update current state
        CurrentState = newState;

        // Notify observers
        await NotifyStateChangedAsync(transition);
    }

    private async Task NotifyStateChangedAsync(StateTransition transition)
    {
        var notification = new StateChangeNotification(transition);
        await _messageBus.PublishAsync(notification);
    }
}

public class ServiceDependencyManager : CommunicationElement
{
    private readonly IServiceDiscovery _discovery;
    private readonly IVersionResolver _versionResolver;

    public async Task VerifyDependenciesAsync(
        IEnumerable<ServiceDependency> dependencies)
    {
        foreach (var dependency in dependencies)
        {
            // Find dependent service
            var service = await _discovery.FindServiceAsync(
                dependency.ServiceName);

            if (service == null && dependency.Required)
                throw new DependencyNotFoundException(dependency);

            // Verify version compatibility
            if (!await _versionResolver.IsCompatibleAsync(
                service.Version, 
                dependency.MinVersion))
            {
                throw new IncompatibleVersionException(
                    dependency, 
                    service.Version);
            }

            // Verify health status
            if (!await IsHealthyAsync(service))
                throw new UnhealthyDependencyException(dependency);
        }
    }
}