Connector checkpointing (#3876)

* wip checkpointing/continue on failure

more stuff for checkpointing

Basic implementation

FE stuff

More checkpointing/failure handling

rebase

rebase

initial scaffolding for IT

IT to test checkpointing

Cleanup

cleanup

Fix it

Rebase

Add todo

Fix actions IT

Test more

Pagination + fixes + cleanup

Fix IT networking

fix it

* rebase

* Address misc comments

* Address comments

* Remove unused router

* rebase

* Fix mypy

* Fixes

* fix it

* Fix tests

* Add drop index

* Add retries

* reset lock timeout

* Try hard drop of schema

* Add timeout/retries to downgrade

* rebase

* test

* test

* test

* Close all connections

* test closing idle only

* Fix it

* fix

* try using null pool

* Test

* fix

* rebase

* log

* Fix

* apply null pool

* Fix other test

* Fix quality checks

* Test not using the fixture

* Fix ordering

* fix test

* Change pooling behavior

backend/ee/onyx/external_permissions/slack/doc_sync.py

@@ -5,7 +5,7 @@ from onyx.access.models import DocExternalAccess
 from onyx.access.models import ExternalAccess
 from onyx.connectors.slack.connector import get_channels
 from onyx.connectors.slack.connector import make_paginated_slack_api_call_w_retries
-from onyx.connectors.slack.connector import SlackPollConnector
+from onyx.connectors.slack.connector import SlackConnector
 from onyx.db.models import ConnectorCredentialPair
 from onyx.indexing.indexing_heartbeat import IndexingHeartbeatInterface
 from onyx.utils.logger import setup_logger
@@ -17,7 +17,7 @@ logger = setup_logger()
 def _get_slack_document_ids_and_channels(
     cc_pair: ConnectorCredentialPair, callback: IndexingHeartbeatInterface | None
 ) -> dict[str, list[str]]:
-    slack_connector = SlackPollConnector(**cc_pair.connector.connector_specific_config)
+    slack_connector = SlackConnector(**cc_pair.connector.connector_specific_config)
     slack_connector.load_credentials(cc_pair.credential.credential_json)
 
     slim_doc_generator = slack_connector.retrieve_all_slim_documents(callback=callback)