Fixing BWC tests

Signed-off-by: Martin Gaievski <[email protected]>

Author: martin-gaievski

server/src/main/java/org/opensearch/search/pipeline/Pipeline.java

@@ -289,7 +289,21 @@ <Result extends SearchPhaseResult> void runSearchPhaseResultsTransformer(
         PipelineProcessingContext requestContext
     ) throws SearchPipelineProcessingException {
         long pipelineStart = relativeTimeSupplier.getAsLong();
-        beforeTransformPhaseResults();
+        boolean hasMatchingProcessors = false;
+        
+        // Check if there are any matching processors before tracking metrics
+        for (SearchPhaseResultsProcessor searchPhaseResultsProcessor : searchPhaseResultsProcessors) {
+            if (currentPhase.equals(searchPhaseResultsProcessor.getBeforePhase().getName())
+                && nextPhase.equals(searchPhaseResultsProcessor.getAfterPhase().getName())) {
+                hasMatchingProcessors = true;
+                break;
+            }
+        }
+        
+        if (hasMatchingProcessors) {
+            beforeTransformPhaseResults();
+        }
+        
         try {
             for (SearchPhaseResultsProcessor searchPhaseResultsProcessor : searchPhaseResultsProcessors) {
                 beforePhaseResultsProcessor(searchPhaseResultsProcessor);
@@ -325,8 +339,10 @@ <Result extends SearchPhaseResult> void runSearchPhaseResultsTransformer(
         } catch (Exception e) {
             throw new SearchPipelineProcessingException(e);
         } finally {
-            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
-            afterTransformPhaseResults(took);
+            if (hasMatchingProcessors) {
+                long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
+                afterTransformPhaseResults(took);
+            }
         }
     }
 

server/src/main/java/org/opensearch/search/pipeline/PipelineWithMetrics.java

@@ -250,6 +250,7 @@ protected void beforeTransformPhaseResults() {
         super.beforeTransformPhaseResults();
         totalPhaseResultsMetrics.before();
         // Phase results processing is also tracked as part of individual pipeline request processing
+        // only when there are matching processors that will actually execute
         pipelineRequestMetrics.before();
     }
 
@@ -258,6 +259,7 @@ protected void afterTransformPhaseResults(long timeInNanos) {
         super.afterTransformPhaseResults(timeInNanos);
         totalPhaseResultsMetrics.after(timeInNanos);
         // Phase results processing is also tracked as part of individual pipeline request processing
+        // only when there are matching processors that will actually execute
         pipelineRequestMetrics.after(timeInNanos);
     }
 
@@ -266,6 +268,7 @@ protected void onTransformPhaseResultsFailure() {
         super.onTransformPhaseResultsFailure();
         totalPhaseResultsMetrics.failed();
         // Phase results processing failures are also tracked as part of individual pipeline request processing
+        // only when there are matching processors that will actually execute
         pipelineRequestMetrics.failed();
     }