[Feature] Adds Warning Status to Lite

Lite/MainWindow.xaml

@@ -108,12 +108,15 @@
                                             <Style TargetType="Ellipse">
                                                 <Setter Property="Fill" Value="{DynamicResource ForegroundMutedBrush}"/>
                                                 <Style.Triggers>
-                                                    <DataTrigger Binding="{Binding IsOnline}" Value="True">
+                                                    <DataTrigger Binding="{Binding DotStatus}" Value="Online">
                                                         <Setter Property="Fill" Value="{DynamicResource SuccessBrush}"/>
                                                     </DataTrigger>
-                                                    <DataTrigger Binding="{Binding IsOnline}" Value="False">
+                                                    <DataTrigger Binding="{Binding DotStatus}" Value="Offline">
                                                         <Setter Property="Fill" Value="{DynamicResource ErrorBrush}"/>
                                                     </DataTrigger>
+                                                    <DataTrigger Binding="{Binding DotStatus}" Value="Warning">
+                                                        <Setter Property="Fill" Value="{DynamicResource WarningBrush}"/>
+                                                    </DataTrigger>
                                                 </Style.Triggers>
                                             </Style>
                                         </Ellipse.Style>

Lite/MainWindow.xaml.cs

@@ -35,6 +35,7 @@ public partial class MainWindow : Window
     private SystemTrayService? _trayService;
     private readonly Dictionary<string, TabItem> _openServerTabs = new();
     private readonly Dictionary<string, bool> _previousConnectionStates = new();
+    private readonly Dictionary<string, bool> _previousCollectorErrorStates = new();
     private readonly Dictionary<string, DateTime> _lastCpuAlert = new();
     private readonly Dictionary<string, DateTime> _lastBlockingAlert = new();
     private readonly Dictionary<string, DateTime> _lastDeadlockAlert = new();
@@ -255,6 +256,9 @@ private void RefreshServerList()
         foreach (var server in servers)
         {
             server.IsOnline = _serverManager.GetConnectionStatus(server.Id).IsOnline;
+            server.HasCollectorErrors = _collectorService != null
+                && server.IsOnline == true
+                && _collectorService.GetHealthSummary(server).ErroringCollectors > 0;
         }
         ServerListView.ItemsSource = servers;
 
@@ -380,6 +384,8 @@ private async Task RefreshOverviewAsync()
                         summary.ServerName = server.ServerName;
                         var connStatus = _serverManager.GetConnectionStatus(server.Id);
                         summary.IsOnline = connStatus.IsOnline;
+                        if (_collectorService != null && connStatus.IsOnline == true)
+                            summary.HasCollectorErrors = _collectorService.GetHealthSummary(server).ErroringCollectors > 0;
                         summaries.Add(summary);
                     }
                 }
@@ -898,6 +904,9 @@ private void CheckConnectionsAndNotify()
                 if (status?.IsOnline == null) continue;
 
                 bool isOnline = status.IsOnline == true;
+                bool hasErrors = _collectorService != null && isOnline
+                    && _collectorService.GetHealthSummary(server).ErroringCollectors > 0;
+                server.HasCollectorErrors = hasErrors;
 
                 if (_previousConnectionStates.TryGetValue(server.Id, out var wasOnline))
                 {
@@ -930,7 +939,11 @@ private void CheckConnectionsAndNotify()
                     needsRefresh = true;
                 }
 
+                if (_previousCollectorErrorStates.TryGetValue(server.Id, out var prevHasErrors) && prevHasErrors != hasErrors)
+                    needsRefresh = true;
+
                 _previousConnectionStates[server.Id] = isOnline;
+                _previousCollectorErrorStates[server.Id] = hasErrors;
             }
 
             if (needsRefresh)

Lite/Models/ServerConnection.cs

@@ -88,6 +88,30 @@ public bool UseWindowsAuth
     [JsonIgnore]
     public bool? IsOnline { get; set; }
 
+    /// <summary>
+    /// Whether one or more collectors are currently failing for this server.
+    /// null = not yet determined; true = some collectors have consecutive errors; false = all healthy.
+    /// </summary>
+    [JsonIgnore]
+    public bool? HasCollectorErrors { get; set; }
+
+    /// <summary>
+    /// Computed dot status for the sidebar indicator. One of: "Unknown", "Online", "Warning", "Offline".
+    /// Drives the Ellipse fill via DataTrigger in MainWindow.xaml.
+    /// </summary>
+    [JsonIgnore]
+    public string DotStatus
+    {
+        get
+        {
+            if (IsOnline == true)
+                return HasCollectorErrors == true ? "Warning" : "Online";
+            if (IsOnline == false)
+                return "Offline";
+            return "Unknown"; // null — not yet checked
+        }
+    }
+
     /// <summary>
     /// Display-only property for showing status in UI.
     /// </summary>

Lite/Services/LocalDataService.Overview.cs

@@ -126,6 +126,8 @@ public class ServerSummaryItem
     public string ServerName { get; set; } = "";
     public int ServerId { get; set; }
     public bool? IsOnline { get; set; }
+    /// <summary>True when the server is reachable but one or more collectors have consecutive errors.</summary>
+    public bool HasCollectorErrors { get; set; }
     public double? CpuPercent { get; set; }
     public double? MemoryMb { get; set; }
     public int BlockingCount { get; set; }
@@ -139,8 +141,20 @@ public class ServerSummaryItem
     public string LastCollectionDisplay => LastCollectionTime.HasValue ? ServerTimeHelper.FormatServerTime(LastCollectionTime, "HH:mm:ss") : "Never";
 
     /* Connection status */
-    public string StatusDisplay => IsOnline switch { true => "Online", false => "Offline", _ => "Unknown" };
-    public SolidColorBrush StatusBrush => MakeBrush(IsOnline switch { true => "#81C784", false => "#E57373", _ => "#888888" });
+    public string StatusDisplay => IsOnline switch
+    {
+        true when HasCollectorErrors => "Warning",
+        true => "Online",
+        false => "Offline",
+        _ => "Unknown"
+    };
+    public SolidColorBrush StatusBrush => MakeBrush(IsOnline switch
+    {
+        true when HasCollectorErrors => "#FFD54F",  // amber — connected but collectors failing
+        true => "#81C784",
+        false => "#E57373",
+        _ => "#888888"
+    });
     public bool IsOffline => IsOnline == false;
 
     /* Color coding */
@@ -152,6 +166,7 @@ public class ServerSummaryItem
         DeadlockCount > 0 ? "#E57373" :
         BlockingCount > 0 ? "#FFB74D" :
         CpuPercent >= 80 ? "#FFB74D" :
+        HasCollectorErrors ? "#FFD54F" :   // amber border when collectors are failing
         "#2a2d35");
 
     private static SolidColorBrush MakeBrush(string hex)

Lite/Services/RemoteCollectorService.cs

@@ -126,6 +126,12 @@ public RemoteCollectorService(
     /// </summary>
     public Task CheckpointAsync() => _duckDb.CheckpointAsync();
 
+    /// <summary>
+    /// Gets a summary of collector health for a specific server connection.
+    /// </summary>
+    public CollectorHealthSummary GetHealthSummary(ServerConnection server)
+        => GetHealthSummary(GetServerId(server));
+
     /// <summary>
     /// Gets a summary of collector health. When serverId is provided, filters to that server only.
     /// </summary>

Lite/Services/ServerManager.cs

@@ -330,50 +330,52 @@ public async Task<ServerConnectionStatus> CheckConnectionAsync(string serverId,
             using var connection = new SqlConnection(builder.ConnectionString);
             await connection.OpenAsync();
 
-            // Query server start time, version, and UTC offset to verify connectivity
-            using var command = new SqlCommand(@"
-                SELECT
-                    sqlserver_start_time,
-                    @@VERSION AS sql_version,
-                    CONVERT(integer, SERVERPROPERTY('ProductMajorVersion')) AS major_version,
-                    DATEDIFF(MINUTE, GETUTCDATE(), GETDATE()) AS utc_offset_minutes,
-                    CONVERT(integer, SERVERPROPERTY('EngineEdition')) AS engine_edition,
-                    CASE WHEN DB_ID('rdsadmin') IS NOT NULL THEN 1 ELSE 0 END AS is_aws_rds
-                FROM sys.dm_os_sys_info", connection);
-            command.CommandTimeout = ConnectionCheckTimeoutSeconds;
-
-            using var reader = await command.ExecuteReaderAsync();
-            if (await reader.ReadAsync())
+            // Connection succeeded — server is reachable regardless of DMV permissions below.
+            status.IsOnline = true;
+            status.ErrorMessage = null;
+            status.UserCancelledMfa = false; // Clear cancellation flag on successful connection
+
+            // Query server metadata (version, start time, UTC offset).
+            // Wrapped in its own try/catch: a permissions failure on sys.dm_os_sys_info
+            // must NOT flip IsOnline back to false — the login itself worked.
+            try
             {
-                status.IsOnline = true;
-                status.ErrorMessage = null;
-                status.UserCancelledMfa = false; // Clear cancellation flag on successful connection
-
-                if (!reader.IsDBNull(0))
-                {
-                    status.ServerStartTime = reader.GetDateTime(0);
-                }
-                if (!reader.IsDBNull(1))
-                {
-                    status.SqlServerVersion = reader.GetString(1);
-                }
-                if (!reader.IsDBNull(2))
-                {
-                    status.SqlMajorVersion = Convert.ToInt32(reader.GetValue(2));
-                }
-                if (!reader.IsDBNull(3))
-                {
-                    status.UtcOffsetMinutes = Convert.ToInt32(reader.GetValue(3));
-                }
-                if (!reader.IsDBNull(4))
+                using var command = new SqlCommand(@"
+                    SELECT
+                        sqlserver_start_time,
+                        @@VERSION AS sql_version,
+                        CONVERT(integer, SERVERPROPERTY('ProductMajorVersion')) AS major_version,
+                        DATEDIFF(MINUTE, GETUTCDATE(), GETDATE()) AS utc_offset_minutes,
+                        CONVERT(integer, SERVERPROPERTY('EngineEdition')) AS engine_edition,
+                        CASE WHEN DB_ID('rdsadmin') IS NOT NULL THEN 1 ELSE 0 END AS is_aws_rds
+                    FROM sys.dm_os_sys_info", connection);
+                command.CommandTimeout = ConnectionCheckTimeoutSeconds;
+
+                using var reader = await command.ExecuteReaderAsync();
+                if (await reader.ReadAsync())
                 {
-                    status.SqlEngineEdition = Convert.ToInt32(reader.GetValue(4));
-                }
-                if (!reader.IsDBNull(5))
-                {
-                    status.IsAwsRds = Convert.ToInt32(reader.GetValue(5)) == 1;
+                    if (!reader.IsDBNull(0))
+                        status.ServerStartTime = reader.GetDateTime(0);
+                    if (!reader.IsDBNull(1))
+                        status.SqlServerVersion = reader.GetString(1);
+                    if (!reader.IsDBNull(2))
+                        status.SqlMajorVersion = Convert.ToInt32(reader.GetValue(2));
+                    if (!reader.IsDBNull(3))
+                        status.UtcOffsetMinutes = Convert.ToInt32(reader.GetValue(3));
+                    if (!reader.IsDBNull(4))
+                        status.SqlEngineEdition = Convert.ToInt32(reader.GetValue(4));
+                    if (!reader.IsDBNull(5))
+                        status.IsAwsRds = Convert.ToInt32(reader.GetValue(5)) == 1;
                 }
             }
+            catch (SqlException metaEx)
+            {
+                // Metadata query failed (e.g. no VIEW SERVER STATE permission) but the
+                // server IS reachable — keep IsOnline = true, just record the warning.
+                status.ErrorMessage = $"Connected, but metadata query failed: {metaEx.Message}";
+                _logger?.LogWarning("Metadata query failed for server '{DisplayName}' (server is still online): {Message}",
+                    server.DisplayName, metaEx.Message);
+            }
 
             _logger?.LogDebug("Connectivity check passed for server '{DisplayName}'", server.DisplayName);
         }