Opc.Ua.Server.DiagnosticsNodeManager.SetDiagnosticsEnabled C# (CSharp) Method

        public void SetDiagnosticsEnabled(ServerSystemContext context, bool enabled)
        {
            List<NodeState> nodesToDelete = new List<NodeState>();

            lock (Lock)
            {
                if (enabled == m_diagnosticsEnabled)
                {
                    return;
                }

                m_diagnosticsEnabled = enabled;

                if (!enabled)
                {
                    // stop scans.
                    if (m_diagnosticsScanTimer != null)
                    {
                        m_diagnosticsScanTimer.Dispose();
                        m_diagnosticsScanTimer = null;
                    }

                    if (m_sessions != null)
                    {
                        for (int ii = 0; ii < m_sessions.Count; ii++)
                        {
                            nodesToDelete.Add(m_sessions[ii].Summary);
                        }

                        m_sessions.Clear();
                    }

                    if (m_subscriptions != null)
                    {
                        for (int ii = 0; ii < m_subscriptions.Count; ii++)
                        {
                            nodesToDelete.Add(m_sessions[ii].Value.Variable);
                        }

                        m_subscriptions.Clear();
                    }

                    // set error for main diagnostics node.
                    if (m_serverDiagnostics != null)
                    {
                        m_serverDiagnostics.Value = null;
                        m_serverDiagnostics.Error = StatusCodes.BadOutOfService;
                        m_serverDiagnostics.Timestamp = DateTime.UtcNow; 
                    }
                                        
                    // get the node.
                    ServerDiagnosticsState diagnosticsNode = (ServerDiagnosticsState)FindPredefinedNode(
                        ObjectIds.Server_ServerDiagnostics,
                        typeof(ServerDiagnosticsState));

                    // clear arrays.
                    if (diagnosticsNode != null)
                    {
                        if (diagnosticsNode.SamplingIntervalDiagnosticsArray != null)
                        {
                            diagnosticsNode.SamplingIntervalDiagnosticsArray.Value = null;
                            diagnosticsNode.SamplingIntervalDiagnosticsArray.StatusCode = StatusCodes.BadOutOfService;
                            diagnosticsNode.SamplingIntervalDiagnosticsArray.Timestamp = DateTime.UtcNow;
                        }
                        
                        if (diagnosticsNode.SubscriptionDiagnosticsArray != null)
                        {
                            diagnosticsNode.SubscriptionDiagnosticsArray.Value = null;
                            diagnosticsNode.SubscriptionDiagnosticsArray.StatusCode = StatusCodes.BadOutOfService; 
                            diagnosticsNode.SubscriptionDiagnosticsArray.Timestamp = DateTime.UtcNow;
                        }

                        if (diagnosticsNode.SessionsDiagnosticsSummary != null)
                        {
                            diagnosticsNode.SessionsDiagnosticsSummary.SessionDiagnosticsArray.Value = null;
                            diagnosticsNode.SessionsDiagnosticsSummary.SessionDiagnosticsArray.StatusCode = StatusCodes.BadOutOfService; 
                            diagnosticsNode.SessionsDiagnosticsSummary.SessionDiagnosticsArray.Timestamp = DateTime.UtcNow;
                        }

                        if (diagnosticsNode.SessionsDiagnosticsSummary != null)
                        {
                            diagnosticsNode.SessionsDiagnosticsSummary.SessionSecurityDiagnosticsArray.Value = null;
                            diagnosticsNode.SessionsDiagnosticsSummary.SessionSecurityDiagnosticsArray.StatusCode = StatusCodes.BadOutOfService; 
                            diagnosticsNode.SessionsDiagnosticsSummary.SessionSecurityDiagnosticsArray.Timestamp = DateTime.UtcNow;
                        }
                    }
                }
            }

            for (int ii = 0; ii < nodesToDelete.Count; ii++)
            {
                DeleteNode(context, nodesToDelete[ii].NodeId);
            }
        }