Bug fix/check for kill more consistently (arangodb#13514)

goedderz · jsteemann · web-flow · commit fa49a03fc3b7 · 2021-02-09T18:15:19.000+01:00
Co-authored-by: Jan &lt;jsteemann@users.noreply.github.com&gt;
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,6 +1,11 @@
 devel
 -----
 
+* Issue #13141: The `move-filters-into-enumerate` optimization, when applied to
+  an EnumerateCollectionNode (i.e. full collection scan), did not do regular
+  checks for the query being killed during the filtering of documents, resulting
+  in the maxRuntime option and manual kill of a query not working timely.
+
 * Simplify the DistributeExecutor and avoid implicit modification of its input
   variable. Previously the DistributeExecutor could update the input variable
   in-place, leading to unexpected results (see #13509).
diff --git a/arangod/Aql/DocumentProducingHelper.cpp b/arangod/Aql/DocumentProducingHelper.cpp
@@ -286,7 +286,8 @@ bool DocumentProducingFunctionContext::checkFilter(
 }
 
 bool DocumentProducingFunctionContext::checkFilter(ExpressionContext& ctx) {
-  if (ADB_UNLIKELY(_numScanned % 1024 == 0 && _query.killed())) {
+  _killCheckCounter = (_killCheckCounter + 1) % 1024;
+  if (ADB_UNLIKELY(_killCheckCounter == 0 && _query.killed())) {
     THROW_ARANGO_EXCEPTION(TRI_ERROR_QUERY_KILLED);
   }
 
diff --git a/arangod/Aql/DocumentProducingHelper.h b/arangod/Aql/DocumentProducingHelper.h
@@ -126,6 +126,7 @@ struct DocumentProducingFunctionContext {
   arangodb::aql::Projections const& _projections;
   size_t _numScanned;
   size_t _numFiltered;
+  uint_fast16_t _killCheckCounter = 0;
 
   /// @brief Builder that is reused to generate projection results 
   arangodb::velocypack::Builder _objectBuilder;

Original file line number	Diff line number	Diff line change
`@@ -286,7 +286,8 @@ bool DocumentProducingFunctionContext::checkFilter(`
`286`	`286`	`}`
`287`	`287`
`288`	`288`	`bool DocumentProducingFunctionContext::checkFilter(ExpressionContext& ctx) {`
`289`		`- if (ADB_UNLIKELY(_numScanned % 1024 == 0 && _query.killed())) {`
	`289`	`+ _killCheckCounter = (_killCheckCounter + 1) % 1024;`
	`290`	`+ if (ADB_UNLIKELY(_killCheckCounter == 0 && _query.killed())) {`
`290`	`291`	`THROW_ARANGO_EXCEPTION(TRI_ERROR_QUERY_KILLED);`
`291`	`292`	`}`
`292`	`293`