Adds a stack-trace to failures from OpenSearch to help with debugging issues. (#1899) (#1902)

Signed-off-by: David Venable <[email protected]>
(cherry picked from commit bd8a7fa)

Co-authored-by: David Venable <[email protected]>

Author: opensearch-trigger-bot[bot]

data-prepper-plugins/opensearch/src/main/java/org/opensearch/dataprepper/plugins/sink/opensearch/OpenSearchSink.java

@@ -219,10 +219,10 @@ private void logFailure(final BulkOperation bulkOperation, final Throwable failu
         dlqWriter.write(String.format("{\"Document\": [%s], \"failure\": %s}\n",
                 BulkOperationWriter.bulkOperationToString(bulkOperation), failure.getMessage()));
       } catch (final IOException e) {
-        LOG.error("DLQ failed for Document [{}]", bulkOperation.toString());
+        LOG.error("DLQ failed for Document [{}]", bulkOperation, e);
       }
     } else {
-      LOG.warn("Document [{}] has failure: {}", bulkOperation.toString(), failure);
+      LOG.warn("Document [{}] has failure.", bulkOperation.toString(), failure);
     }
   }