Reliably stop abandoned read-only requests and their queries

api/src/org/labkey/api/ApiModule.java

@@ -54,6 +54,7 @@
 import org.labkey.api.data.AbstractForeignKey;
 import org.labkey.api.data.AccumulatingCommitTask;
 import org.labkey.api.data.Aggregate;
+import org.labkey.api.data.AsyncQueryRequest;
 import org.labkey.api.data.AtomicDatabaseInteger;
 import org.labkey.api.data.BindingTestCase;
 import org.labkey.api.data.BooleanFormat;
@@ -78,6 +79,7 @@
 import org.labkey.api.data.NameGenerator;
 import org.labkey.api.data.PropertyManager;
 import org.labkey.api.data.RecordFactory;
+import org.labkey.api.data.RequestCancellation;
 import org.labkey.api.data.RepeatedCommitTaskMonitor;
 import org.labkey.api.data.ResultSetSelectorTestCase;
 import org.labkey.api.data.RowTrackingResultSetWrapper;
@@ -92,6 +94,7 @@
 import org.labkey.api.data.Table;
 import org.labkey.api.data.TableSelectorTestCase;
 import org.labkey.api.data.TempTableInClauseGenerator;
+import org.labkey.api.data.TransactionFilter;
 import org.labkey.api.data.WorkbookContainerType;
 import org.labkey.api.data.dialect.JdbcMetaDataTest;
 import org.labkey.api.data.dialect.ParameterSubstitutionTest;
@@ -528,6 +531,7 @@ public void registerServlets(ServletContext servletCtx)
             ApiKeyManager.TestCase.class,
             ApiQueryResponse.TestCase.class,
             AppPropsTestCase.class,
+            AsyncQueryRequest.TestCase.class,
             AtomicDatabaseInteger.TestCase.class,
             BindingTestCase.class,
             BlockingCache.BlockingCacheTest.class,
@@ -573,6 +577,7 @@ public void registerServlets(ServletContext servletCtx)
             QueryDataIteratorBuilder.TestCase.class,
             QueryView.TestCase.class,
             RecordFactory.TestCase.class,
+            RequestCancellation.TestCase.class,
             RepeatedCommitTaskMonitor.IntegrationTestCase.class,
             ResultSetDataIterator.TestCase.class,
             ResultSetSelectorTestCase.class,
@@ -592,6 +597,7 @@ public void registerServlets(ServletContext servletCtx)
             Table.TestCase.class,
             TableSelectorTestCase.CoreTableSelectorTest.class,
             TempTableInClauseGenerator.TestCase.class,
+            TransactionFilter.TestCase.class,
             URLHelper.TestCase.class,
             UserKeySimpleCache.TestCase.class,
             UserManager.TestCase.class,

api/src/org/labkey/api/action/ApiResponseWriter.java

@@ -232,6 +232,9 @@ public int getErrorResponseStatus(Throwable ex)
         if (ex instanceof HttpStatusException statusEx)
             return statusEx.getStatus();
 
+        if (ExceptionUtil.isRequestTimeout(ex))
+            return HttpServletResponse.SC_SERVICE_UNAVAILABLE;
+
         if (ex instanceof BatchValidationException || ex instanceof ValidationException)
             return defaultErrorStatus;
 
@@ -262,12 +265,13 @@ public final void writeResponse(Object obj) throws IOException
     public void writeResponse(Throwable e) throws IOException
     {
         int status = getErrorResponseStatus(e);
+        boolean timedOut = ExceptionUtil.isRequestTimeout(e);
         e = ExceptionUtil.unwrapException(e);
 
         try
         {
             setResponseStatus(status);
-            var json = toJSON(e);
+            var json = timedOut ? new JSONObject().put("exception", ExceptionUtil.REQUEST_TIMEOUT_MESSAGE) : toJSON(e);
             json.put("success", false);
             writeObject(json);
         }

api/src/org/labkey/api/action/SpringActionController.java

@@ -569,6 +569,7 @@ public ModelAndView handleRequest(HttpServletRequest request, @NotNull HttpServl
 
             checkable.checkPermissions();
 
+            boolean export = ExportAction.class.isAssignableFrom(actionClass);
             // Actions can annotate themselves with an ActionType, which helps custom schemas that want to limit access from generic actions
             if (actionClass.isAnnotationPresent(Action.class))
             {
@@ -578,12 +579,16 @@ public ModelAndView handleRequest(HttpServletRequest request, @NotNull HttpServl
                     actionAnnotation.value().equals(ActionType.SelectData.class) ||
                     actionAnnotation.value().equals(ActionType.SelectMetaData.class))
                 {
-                    // Consider these action types read-only and eligible for killing after a timeout
+                    // Consider these action types read-only and, except for exports, eligible for killing after a timeout
                     request.setAttribute(TransactionFilter.READ_ONLY_ATTRIBUTE_NAME, true);
                 }
+                export |= actionAnnotation.value().equals(ActionType.Export.class);
                 QueryService.get().setEnvironment(QueryService.Environment.ACTION, actionAnnotation.value());
             }
 
+            if (export)
+                request.setAttribute(TransactionFilter.EXPORT_ATTRIBUTE_NAME, true);
+
             // After the permission check so unauthorized requests can't consume @ConcurrencyLimit permits, and held
             // through rendering because the action's memory is live for that whole time.
             try (ConcurrencyLimiter.Permit ignored = ConcurrencyLimiter.acquire(actionClass, context))