chore: add debug logging for sqs batch processing

Author: Tom McCarthy

aws_lambda_powertools/utilities/batch/base.py

@@ -4,11 +4,14 @@
 Batch processing utilities
 """
 
+import logging
 from abc import ABC, abstractmethod
 from typing import Any, Callable, Dict, Iterable, List, Tuple
 
 from aws_lambda_powertools.middleware_factory import lambda_handler_decorator
 
+logger = logging.getLogger(__name__)
+
 
 class BasePartialProcessor(ABC):
     """
@@ -92,6 +95,7 @@ def failure_handler(self, record: Any, exception: Exception):
             "fail", exceptions args, original record
         """
         entry = ("fail", exception.args, record)
+        logger.debug("Record processing exception: ", exception)
         self.exceptions.append(exception)
         self.fail_messages.append(record)
         return entry

aws_lambda_powertools/utilities/batch/sqs.py

@@ -3,6 +3,7 @@
 """
 Batch SQS utilities
 """
+import logging
 from typing import Callable, Dict, List, Optional, Tuple
 
 import boto3
@@ -12,6 +13,8 @@
 from .base import BasePartialProcessor
 from .exceptions import SQSBatchProcessingError
 
+logger = logging.getLogger(__name__)
+
 
 class PartialSQSProcessor(BasePartialProcessor):
     """
@@ -106,14 +109,18 @@ def _clean(self):
         # If all messages were successful, fall back to the default SQS -
         # Lambda behaviour which deletes messages if Lambda responds successfully
         if not self.fail_messages:
+            logger.debug(f"All {len(self.success_messages)} records successfully processed")
             return
 
         queue_url = self._get_queue_url()
         entries_to_remove = self._get_entries_to_clean()
 
         delete_message_response = self.client.delete_message_batch(QueueUrl=queue_url, Entries=entries_to_remove)
 
-        if self.fail_messages and not self.suppress_exception:
+        if self.suppress_exception:
+            logger.debug(f"{len(self.fail_messages)} records failed processing, but exceptions are suppressed")
+        else:
+            logger.debug(f"{len(self.fail_messages)} records failed processing, raising exception")
             raise SQSBatchProcessingError(list(self.exceptions))
 
         return delete_message_response