[PATCH] DEV-2614: @t_db_retry: don't retry when attempting write operations on read-only t.db

mediaire_toolbox/transaction_db/t_db_retry.py

@@ -1,6 +1,7 @@
 import logging
 
-from tenacity.retry import retry_if_exception_type
+from tenacity.retry import (retry_if_exception_type,
+                            retry_if_not_exception_message)
 from tenacity import retry, stop_after_attempt, wait_fixed
 
 from sqlite3 import OperationalError as Sqlite3OperationalError
@@ -18,21 +19,28 @@
 Database retry logic for the Transactions DB.
 Retry up to a maximum amount of times, with a fixed wait period inbetween.
 Retry only for certain exceptions that we know are problematic.
+Don't retry when attempting write operations on read-only databases.
 """
 
 
 def before_sleep_log(retry_state):
-    default_logger.warn(
+    default_logger.warning(
         'Retrying {}: attempt {} ended with: {}'
         .format(retry_state.fn, retry_state.attempt_number,
                 retry_state.outcome))
 
 
 def t_db_retry(f):
+    """Retries only when specific sqlite3 Exceptions are raised and when
+    they don't correspond failed write operations on read-only databases
+    (message will be something like 'attempt to write a readonly database')
+    """
     return retry(
         retry=(
-            retry_if_exception_type(OperationalError)
-            | retry_if_exception_type(Sqlite3OperationalError)),
+            (retry_if_exception_type(OperationalError)
+             | retry_if_exception_type(Sqlite3OperationalError))
+            & retry_if_not_exception_message(match='.*read.?only.*')
+        ),
         stop=stop_after_attempt(RETRY_DATABASE_OP_TIMES),
         wait=wait_fixed(RETRY_DATABASE_OP_SECONDS),
         before_sleep=before_sleep_log)(f)