microsoft · ahmetziyayildirim · Sep 18, 2026
diff --git a/Agents/Implementation Agents/Trace Parser/TraceParserWeb/README.md b/Agents/Implementation Agents/Trace Parser/TraceParserWeb/README.md
@@ -122,8 +122,14 @@ Deploy the updated **read-only** `TraceParserMCP/dab-config.json` as part of thi
 
 ### Deletion regression checks
 
-The dependency-free console harness checks denied anonymous/wrong-tenant calls, ordinary tenant-user access, disabled configuration, incremental completion, failure/cancellation propagation, and read-only DAB permissions. It uses synthetic identities and a fake store, with no database or network calls:
+The dependency-free console harness checks deletion authorization/completion, read-only DAB permissions, import-status query/error handling, visible deletion feedback, and non-overlapping status polls. It uses synthetic identities and fake stores/HTTP responses, with no database or network calls:
 
 ```powershell
 dotnet run --project .\tests\TraceParserWeb.RegressionTests -c Release
 ```
+
+## Import status and database maintenance
+
+Status polling uses DAB's `$first` parameter, not OData's unsupported `$top`. The upload and trace-list pages share the same database-milestone checks. HTTP failures, timeouts and malformed responses are displayed as **status unavailable**, not as evidence that the Function is parsing or queued. Each page permits only one status poll at a time.
+
+Trace-list labels describe data availability, not a live worker heartbeat. For example, an empty trace has no parsed session data; that alone does not prove an ETL job is running. SQL index maintenance can delay status queries and deletion. Deletion errors appear above the trace list so a timeout is not hidden below other records. Do not treat a timeout as successful deletion or repeatedly submit deletes while maintenance is blocking SQL.
diff --git a/...Agents/Trace Parser/TraceParserWeb/TraceParserWeb/Components/Pages/Traces/TraceList.razor b/...Agents/Trace Parser/TraceParserWeb/TraceParserWeb/Components/Pages/Traces/TraceList.razor
@@ -28,6 +28,13 @@
             </div>
         </div>
 
+        @if (!string.IsNullOrEmpty(_statusMessage))
+        {
+            <div role="status" class="traces-status @(_statusIsError ? "status-error" : "status-success")">
+                @_statusMessage
+            </div>
+        }
+
         @if (_loading)
         {
             <div class="traces-loading">
@@ -89,7 +96,6 @@
                             else if (_importingStages.TryGetValue(trace.TraceId, out var stage))
                             {
                                 <div class="trace-importing">
-                                    <span class="importing-spinner"></span>
                                     <span class="importing-text">@GetImportStageText(stage)</span>
                                 </div>
                             }
@@ -126,12 +132,6 @@
             </div>
         }
 
-        @if (!string.IsNullOrEmpty(_statusMessage))
-        {
-            <div class="traces-status @(_statusIsError ? "status-error" : "status-success")">
-                @_statusMessage
-            </div>
-        }
     </div>
 </div>
 
@@ -147,6 +147,8 @@
     string? _statusMessage;
     bool _statusIsError;
     System.Threading.Timer? _importPollTimer;
+    int _pollInProgress;
+    bool _disposed;
 
     protected override async Task OnInitializedAsync()
     {
@@ -193,28 +195,40 @@
         // Check stage for each trace without stats
         foreach (var trace in tracesWithoutStats)
         {
+            if (_disposed) return;
             var stage = await TraceSvc.GetImportStageAsync(trace.TraceId);
+            if (_disposed) return;
             if (stage != ImportStage.Complete)
                 _importingStages[trace.TraceId] = stage;
         }
 
         if (_importingStages.Count == 0) return;
 
         // Start polling importing traces every 10s
-        _importPollTimer = new System.Threading.Timer(async _ =>
+        _importPollTimer = new System.Threading.Timer(async _ => await PollImportStagesAsync(),
+            null, TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(10));
+    }
+
+    async Task PollImportStagesAsync()
+    {
+        if (Interlocked.CompareExchange(ref _pollInProgress, 1, 0) != 0) return;
+        try
         {
-            try
+            await InvokeAsync(async () =>
             {
+                if (_disposed) return;
                 var changed = false;
                 foreach (var traceId in _importingStages.Keys.ToList())
                 {
                     var stage = await TraceSvc.GetImportStageAsync(traceId);
+                    if (_disposed) return;
+                    if (!_importingStages.TryGetValue(traceId, out var previousStage)) continue;
                     if (stage == ImportStage.Complete)
                     {
                         _importingStages.Remove(traceId);
                         changed = true;
                     }
-                    else if (_importingStages[traceId] != stage)
+                    else if (previousStage != stage)
                     {
                         _importingStages[traceId] = stage;
                         changed = true;
@@ -236,13 +250,17 @@
                     }
                 }
 
-                await InvokeAsync(StateHasChanged);
-            }
-            catch (Exception ex)
-            {
-                Logger.LogWarning(ex, "Import poll error on Traces page");
-            }
-        }, null, TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(10));
+                if (!_disposed) StateHasChanged();
+            });
+        }
+        catch (Exception ex)
+        {
+            Logger.LogWarning(ex, "Import poll error on Traces page");
+        }
+        finally
+        {
+            Volatile.Write(ref _pollInProgress, 0);
+        }
     }
 
     void RequestDelete(int traceId)
@@ -270,6 +288,7 @@
             _statusIsError = false;
             _traces.RemoveAll(t => t.TraceId == traceId);
             _traceStats.Remove(traceId);
+            _importingStages.Remove(traceId);
         }
         catch (Exception ex)
         {
@@ -304,14 +323,16 @@
     static string GetImportStageText(ImportStage stage) => stage switch
     {
         ImportStage.WaitingForFunction => "Waiting for processing...",
-        ImportStage.Parsing => "Parsing ETL events...",
-        ImportStage.ProcessingDimensions => "Importing trace lines...",
-        ImportStage.Finalizing => "Finalizing...",
-        _ => "Importing..."
+        ImportStage.Parsing => "No parsed session data available yet.",
+        ImportStage.ProcessingDimensions => "Waiting for trace lines.",
+        ImportStage.Finalizing => "Waiting for session metrics.",
+        ImportStage.Unavailable => "Import status unavailable; the next poll will retry.",
+        _ => "Import status not confirmed."
     };
 
     public void Dispose()
     {
+        _disposed = true;
         _importPollTimer?.Dispose();
     }
 }
diff --git a/...Agents/Trace Parser/TraceParserWeb/TraceParserWeb/Components/Pages/Upload/EtlUpload.razor b/...Agents/Trace Parser/TraceParserWeb/TraceParserWeb/Components/Pages/Upload/EtlUpload.razor
@@ -176,6 +176,8 @@
     long _uploadedBytes;
     string StatusMessage = "";
     System.Threading.Timer? _pollTimer;
+    int _pollInProgress;
+    bool _disposed;
     DotNetObjectReference<EtlUpload>? _dotNetRef;
     ImportStage _currentStage = ImportStage.WaitingForFunction;
     DateTime _processingStartTime;
@@ -278,11 +280,20 @@
         Logger.LogInformation("Direct blob upload complete for session {Session}", SessionName);
 
         // Start polling for import stage
-        _pollTimer = new System.Threading.Timer(async _ =>
+        _pollTimer = new System.Threading.Timer(async _ => await PollImportStatusAsync(),
+            null, TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(5));
+    }
+
+    async Task PollImportStatusAsync()
+    {
+        if (Interlocked.CompareExchange(ref _pollInProgress, 1, 0) != 0) return;
+        try
         {
-            try
+            await InvokeAsync(async () =>
             {
+                if (_disposed) return;
                 var status = await UploadSvc.GetImportStatusAsync(SessionName, CancellationToken.None);
+                if (_disposed) return;
 
                 if (status.Stage != _currentStage)
                 {
@@ -300,13 +311,17 @@
                     StatusMessage = $"Import complete! Session '{SessionName}' is ready to query in Chat.";
                 }
 
-                await InvokeAsync(StateHasChanged);
-            }
-            catch (Exception ex)
-            {
-                Logger.LogWarning(ex, "Status poll error for session {Session}", SessionName);
-            }
-        }, null, TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(5));
+                StateHasChanged();
+            });
+        }
+        catch (Exception ex)
+        {
+            Logger.LogWarning(ex, "Status poll error for session {Session}", SessionName);
+        }
+        finally
+        {
+            Volatile.Write(ref _pollInProgress, 0);
+        }
     }
 
     [JSInvokable]
@@ -339,6 +354,7 @@
         ImportStage.ProcessingDimensions => "Promoting trace lines and rebuilding indexes...",
         ImportStage.Finalizing => "Computing session aggregations...",
         ImportStage.Complete => "Import complete!",
+        ImportStage.Unavailable => "Import status unavailable; the next poll will retry.",
         _ => "Processing..."
     };
 
@@ -348,6 +364,7 @@
         ImportStage.Parsing => "Parsing",
         ImportStage.ProcessingDimensions => "Importing",
         ImportStage.Finalizing => "Finalizing",
+        ImportStage.Unavailable => "Unavailable",
         _ => ""
     };
 
@@ -384,6 +401,7 @@
 
     public void Dispose()
     {
+        _disposed = true;
         _pollTimer?.Dispose();
         _dotNetRef?.Dispose();
     }

diff --git a/...ementation Agents/Trace Parser/TraceParserWeb/TraceParserWeb/Services/EtlUploadService.cs b/...ementation Agents/Trace Parser/TraceParserWeb/TraceParserWeb/Services/EtlUploadService.cs
@@ -9,6 +9,7 @@ namespace TraceParserWeb.Services;
 
 public enum ImportStage
 {
+    Unavailable = -1,
     WaitingForFunction,
     Parsing,
     ProcessingDimensions,
@@ -29,7 +30,11 @@ public class EtlImportOptions
     public string DabBaseUrl { get; set; } = "";
 }
 
-public class EtlUploadService(IOptions<EtlImportOptions> opts, IHttpClientFactory httpFactory)
+public class EtlUploadService(
+    IOptions<EtlImportOptions> opts,
+    IHttpClientFactory httpFactory,
+    TraceService traceService,
+    ILogger<EtlUploadService> logger)
 {
     /// <summary>
     /// Uploads an ETL file to Azure Blob Storage under {sessionName}/{fileName}.
@@ -80,40 +85,29 @@ public async Task<ImportStatus> GetImportStatusAsync(string sessionName, Cancell
     {
         try
         {
-            var http = httpFactory.CreateClient("dab");
+            using var cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
+            cts.CancelAfter(TimeSpan.FromSeconds(10));
+            using var http = httpFactory.CreateClient("dab");
 
             // Step 1: Find the trace
-            var url = $"/api/Traces?$filter=TraceName eq '{Uri.EscapeDataString(sessionName)}'";
-            var resp = await http.GetFromJsonAsync<JsonElement>(url, ct);
-            if (!resp.TryGetProperty("value", out var arr) || arr.GetArrayLength() == 0)
+            var escapedName = Uri.EscapeDataString(sessionName.Replace("'", "''"));
+            var url = $"/api/Traces?$filter=TraceName eq '{escapedName}'&$first=1&$select=TraceId";
+            var resp = await http.GetFromJsonAsync<JsonElement>(url, cts.Token);
+            var arr = TraceService.ReadRows(resp);
+            if (arr.GetArrayLength() == 0)
                 return new ImportStatus { Stage = ImportStage.WaitingForFunction };
 
-            var traceId = arr[0].GetProperty("TraceId").GetInt32();
-
-            // Step 2: Check threads exist (created during BulkInsertDimensions, after staging)
-            var threadUrl = $"/api/UserSessionProcessThreads?$filter=TraceId eq {traceId}&$top=1";
-            var threadResp = await http.GetFromJsonAsync<JsonElement>(threadUrl, ct);
-            if (!threadResp.TryGetProperty("value", out var threadArr) || threadArr.GetArrayLength() == 0)
-                return new ImportStatus { Stage = ImportStage.Parsing, TraceId = traceId };
-
-            // Step 3: Verify TraceLines exist (the final promote step)
-            var threadId = threadArr[0].GetProperty("UserSessionProcessThreadId").GetInt32();
-            var tlUrl = $"/api/TraceLines?$filter=UserSessionProcessThreadId eq {threadId}&$top=1";
-            var tlResp = await http.GetFromJsonAsync<JsonElement>(tlUrl, ct);
-            if (!tlResp.TryGetProperty("value", out var tlArr) || tlArr.GetArrayLength() == 0)
-                return new ImportStatus { Stage = ImportStage.ProcessingDimensions, TraceId = traceId };
-
-            // Step 4: Check SessionMetrics exist (aggregation complete)
-            var smUrl = $"/api/SessionMetrics?$filter=TraceId eq {traceId}&$top=1";
-            var smResp = await http.GetFromJsonAsync<JsonElement>(smUrl, ct);
-            if (!smResp.TryGetProperty("value", out var smArr) || smArr.GetArrayLength() == 0)
-                return new ImportStatus { Stage = ImportStage.Finalizing, TraceId = traceId };
-
-            return new ImportStatus { Stage = ImportStage.Complete, TraceId = traceId };
+            var traceId = TraceService.ReadId(arr[0], "TraceId");
+            return new ImportStatus {
+                Stage = await traceService.GetImportStageAsync(traceId, cts.Token),
+                TraceId = traceId
+            };
         }
-        catch
+        catch (Exception ex) when (ex is HttpRequestException or JsonException or OperationCanceledException)
         {
-            return new ImportStatus { Stage = ImportStage.WaitingForFunction };
+            ct.ThrowIfCancellationRequested();
+            logger.LogWarning(ex, "Import status lookup unavailable");
+            return new ImportStatus { Stage = ImportStage.Unavailable };
         }
     }
 

diff --git a/...Implementation Agents/Trace Parser/TraceParserWeb/TraceParserWeb/Services/TraceService.cs b/...Implementation Agents/Trace Parser/TraceParserWeb/TraceParserWeb/Services/TraceService.cs
@@ -35,7 +35,7 @@ public class TraceStats
     public int TotalDatabaseCalls { get; set; }
 }
 
-public class TraceService(IHttpClientFactory httpFactory)
+public class TraceService(IHttpClientFactory httpFactory, ILogger<TraceService> logger)
 {
     public async Task<List<TraceDto>> GetTracesAsync(CancellationToken ct = default)
     {
@@ -110,32 +110,53 @@ public async Task<ImportStage> GetImportStageAsync(int traceId, CancellationToke
             using var cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
             cts.CancelAfter(TimeSpan.FromSeconds(10));
 
-            var http = httpFactory.CreateClient("dab");
+            using var http = httpFactory.CreateClient("dab");
 
             // Check USPT exists
-            var threadUrl = $"/api/UserSessionProcessThreads?$filter=TraceId eq {traceId}&$top=1";
+            var threadUrl = $"/api/UserSessionProcessThreads?$filter=TraceId eq {traceId}&$first=1&$select=UserSessionProcessThreadId";
             var threadResp = await http.GetFromJsonAsync<JsonElement>(threadUrl, cts.Token);
-            if (!threadResp.TryGetProperty("value", out var threadArr) || threadArr.GetArrayLength() == 0)
+            var threadArr = ReadRows(threadResp);
+            if (threadArr.GetArrayLength() == 0)
                 return ImportStage.Parsing;
 
             // Check TraceLines exist
-            var threadId = threadArr[0].GetProperty("UserSessionProcessThreadId").GetInt32();
-            var tlUrl = $"/api/TraceLines?$filter=UserSessionProcessThreadId eq {threadId}&$top=1";
+            var threadId = ReadId(threadArr[0], "UserSessionProcessThreadId");
+            var tlUrl = $"/api/TraceLines?$filter=UserSessionProcessThreadId eq {threadId}&$first=1&$select=TraceLineId";
             var tlResp = await http.GetFromJsonAsync<JsonElement>(tlUrl, cts.Token);
-            if (!tlResp.TryGetProperty("value", out var tlArr) || tlArr.GetArrayLength() == 0)
+            if (ReadRows(tlResp).GetArrayLength() == 0)
                 return ImportStage.ProcessingDimensions;
 
             // Check SessionMetrics exist
-            var smUrl = $"/api/SessionMetrics?$filter=TraceId eq {traceId}&$top=1";
+            var smUrl = $"/api/SessionMetrics?$filter=TraceId eq {traceId}&$first=1&$select=TraceId";
             var smResp = await http.GetFromJsonAsync<JsonElement>(smUrl, cts.Token);
-            if (!smResp.TryGetProperty("value", out var smArr) || smArr.GetArrayLength() == 0)
+            if (ReadRows(smResp).GetArrayLength() == 0)
                 return ImportStage.Finalizing;
 
             return ImportStage.Complete;
         }
-        catch
+        catch (Exception ex) when (ex is HttpRequestException or JsonException or OperationCanceledException)
         {
-            return ImportStage.Parsing;
+            ct.ThrowIfCancellationRequested();
+            logger.LogWarning(ex, "Import status unavailable for trace {TraceId}", traceId);
+            return ImportStage.Unavailable;
         }
     }
+
+    internal static JsonElement ReadRows(JsonElement response)
+    {
+        if (response.ValueKind != JsonValueKind.Object
+            || !response.TryGetProperty("value", out var rows)
+            || rows.ValueKind != JsonValueKind.Array)
+            throw new JsonException("DAB returned an invalid row collection.");
+        return rows;
+    }
+
+    internal static int ReadId(JsonElement row, string property)
+    {
+        if (row.ValueKind != JsonValueKind.Object
+            || !row.TryGetProperty(property, out var id)
+            || id.ValueKind != JsonValueKind.Number || !id.TryGetInt32(out var value))
+            throw new JsonException("DAB returned an invalid identifier.");
+        return value;
+    }
 }