When an exception happens within the session processor loop, record a… (#4638)

…nd move on

## What type of PR is this? (check all applicable)

- [ ] Refactor
- [ ] Feature
- [ ] Bug Fix
- [ ] Optimization
- [ ] Documentation Update
- [ ] Community Node Submission


## Have you discussed this change with the InvokeAI team?
- [ ] Yes
- [ ] No, because:

      
## Have you updated all relevant documentation?
- [ ] Yes
- [ ] No


## Description


## Related Tickets & Documents

<!--
For pull requests that relate or close an issue, please include them
below. 

For example having the text: "closes #1234" would connect the current
pull
request to issue 1234.  And when we merge the pull request, Github will
automatically close the issue.
-->

- Related Issue #
- Closes #

## QA Instructions, Screenshots, Recordings

<!-- 
Please provide steps on how to test changes, any hardware or 
software specifications as well as any other pertinent information. 
-->

## Added/updated tests?

- [ ] Yes
- [ ] No : _please replace this line with details on why tests
      have not been included_

## [optional] Are there any post deployment tasks we need to perform?

invokeai/app/services/session_processor/session_processor_default.py

@@ -92,30 +92,34 @@ class DefaultSessionProcessor(SessionProcessorBase):
             self.__invoker.services.logger
             while not stop_event.is_set():
                 poll_now_event.clear()
+                try:
+                    # do not dequeue if there is already a session running
+                    if self.__queue_item is None and resume_event.is_set():
+                        queue_item = self.__invoker.services.session_queue.dequeue()
 
-                # do not dequeue if there is already a session running
+                        if queue_item is not None:
-                if self.__queue_item is None and resume_event.is_set():
+                            self.__invoker.services.logger.debug(f"Executing queue item {queue_item.item_id}")
-                    queue_item = self.__invoker.services.session_queue.dequeue()
+                            self.__queue_item = queue_item
+                            self.__invoker.services.graph_execution_manager.set(queue_item.session)
+                            self.__invoker.invoke(
+                                session_queue_batch_id=queue_item.batch_id,
+                                session_queue_id=queue_item.queue_id,
+                                session_queue_item_id=queue_item.item_id,
+                                graph_execution_state=queue_item.session,
+                                invoke_all=True,
+                            )
+                            queue_item = None
 
-                    if queue_item is not None:
+                    if queue_item is None:
-                        self.__invoker.services.logger.debug(f"Executing queue item {queue_item.item_id}")
+                        self.__invoker.services.logger.debug("Waiting for next polling interval or event")
-                        self.__queue_item = queue_item
+                        poll_now_event.wait(POLLING_INTERVAL)
-                        self.__invoker.services.graph_execution_manager.set(queue_item.session)
+                        continue
-                        self.__invoker.invoke(
+                except Exception as e:
-                            session_queue_batch_id=queue_item.batch_id,
+                    self.__invoker.services.logger.error(f"Error in session processor: {e}")
-                            session_queue_id=queue_item.queue_id,
-                            session_queue_item_id=queue_item.item_id,
-                            graph_execution_state=queue_item.session,
-                            invoke_all=True,
-                        )
-                        queue_item = None
-
-                if queue_item is None:
-                    self.__invoker.services.logger.debug("Waiting for next polling interval or event")
                     poll_now_event.wait(POLLING_INTERVAL)
                     continue
         except Exception as e:
-            self.__invoker.services.logger.error(f"Error in session processor: {e}")
+            self.__invoker.services.logger.error(f"Fatal Error in session processor: {e}")
             pass
         finally:
             stop_event.clear()