fix: end remote build metrics before falling back to CPU, log exception

Signed-off-by: owenhalpert <[email protected]>

Author: owenhalpert

CHANGELOG.md

@@ -13,6 +13,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Bug Fixes
 * [BUGFIX] Fix KNN Quantization state cache have an invalid weight threshold [#2666](https://github.com/opensearch-project/k-NN/pull/2666)
 * [BUGFIX] Fix enable rescoring when dimensions > 1000. [#2671](https://github.com/opensearch-project/k-NN/pull/2671) 
+* [Remote Vector Index Build]  End remote build metrics before falling back to CPU, exception logging
 
 ## [Unreleased 2.x](https://github.com/opensearch-project/k-NN/compare/2.19...2.x)
 ### Features

src/main/java/org/opensearch/knn/index/codec/nativeindex/remote/RemoteIndexBuildStrategy.java

@@ -130,7 +130,6 @@ public static boolean shouldBuildIndexRemotely(IndexSettings indexSettings, long
     @Override
     public void buildAndWriteIndex(BuildIndexParams indexInfo) throws IOException {
         metrics.startRemoteIndexBuildMetrics(indexInfo);
-        boolean success = false;
         try {
             RepositoryContext repositoryContext = getRepositoryContext(indexInfo);
 
@@ -147,11 +146,10 @@ public void buildAndWriteIndex(BuildIndexParams indexInfo) throws IOException {
             // 4. Download index file and write to indexOutput
             readFromRepository(indexInfo, repositoryContext, remoteBuildStatusResponse);
 
-            success = true;
+            metrics.endRemoteIndexBuildMetrics(true);
         } catch (Exception e) {
+            metrics.endRemoteIndexBuildMetrics(false);
             fallbackStrategy.buildAndWriteIndex(indexInfo);
-        } finally {
-            metrics.endRemoteIndexBuildMetrics(success);
         }
     }
 
@@ -172,7 +170,7 @@ private void writeToRepository(RepositoryContext repositoryContext, BuildIndexPa
             );
             success = true;
         } catch (InterruptedException | IOException e) {
-            log.debug("Repository write failed for vector field [{}]", indexInfo.getFieldName());
+            log.debug("Repository write failed for vector field [{}]", indexInfo.getFieldName(), e);
             throw e;
         } finally {
             metrics.endRepositoryWriteMetrics(success);
@@ -200,7 +198,7 @@ private RemoteBuildResponse submitBuild(RepositoryContext repositoryContext, Bui
             success = true;
             return remoteBuildResponse;
         } catch (IOException e) {
-            log.debug("Submit vector build failed for vector field [{}]", indexInfo.getFieldName());
+            log.debug("Submit vector build failed for vector field [{}]", indexInfo.getFieldName(), e);
             throw e;
         } finally {
             metrics.endBuildRequestMetrics(success);
@@ -250,7 +248,7 @@ private void readFromRepository(
             );
             success = true;
         } catch (Exception e) {
-            log.debug("Repository read failed for vector field [{}]", indexInfo.getFieldName());
+            log.debug("Repository read failed for vector field [{}]", indexInfo.getFieldName(), e);
             throw e;
         } finally {
             metrics.endRepositoryReadMetrics(success);