# Getting 'default' error on migration **URL:** \ **Category:** Support\ **Created:** [January 14, 2025, 6:10pm UTC](https://forum.weaviate.io/t/getting-default-error-on-migration/9753 "2025-01-14T18:10:46Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Tejas\_Sharma](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/tejas_sharma/32/2086_2.png) [@Tejas\_Sharma](https://forum.weaviate.io/u/Tejas_Sharma)\ **Post date:** [January 14, 2025, 6:10pm UTC](https://forum.weaviate.io/t/getting-default-error-on-migration/9753/1 "2025-01-14T18:10:46Z")
### Description I’m following the migration script to move from a normal cluster to an HA one with the script given: ```auto def migrate_data(collection_src, collection_tgt): with collection_tgt.batch.fixed_size(batch_size=100) as batch: for q in tqdm(collection_src.iterator(include_vector=True)): batch.add_object( properties=q.properties, vector=q.vector["default"], uuid=q.uuid ) return True print('Migrating # of tenants: ', len(tenants_src_list)) i = 0 for tenant in tenants_src_list: print('Migrating tenant: ', tenant.name) try: collection_src_tenant = nodes_collection_source.with_tenant(tenant.name) collection_tgt_tenant = nodes_collection_target.with_tenant(tenant.name) migrate_data(collection_src_tenant, collection_tgt_tenant) except Exception as e: print(e) continue i += 1 print('Migrated tenants up to # ', i) client_source.close() client_target.close() ``` But for some tenants, I get this error logged of just **default** No other error message in the`print(e)` except just that. I’m not sure if this is anything serious before I go ahead with this. I also sent a support email about this in case our specific node(s) are affected ### Server Setup Information - Weaviate Server Version: Servless - Deployment Method: - Multi Node? Number of Running Nodes: - Client Language and Version: - Multitenancy?: Yes ### Any additional Information ---
**Author:** ![Shahin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/shahin/32/8085_2.png) [@Shahin](https://forum.weaviate.io/u/Shahin)\ **Post date:** [January 16, 2025, 2:44pm UTC](https://forum.weaviate.io/t/getting-default-error-on-migration/9753/2 "2025-01-16T14:44:05Z")
Hey @Tejas_Sharma, Have you tried to print out the failed object in a batch then check upon the reason also maybe apply some retry at the end? > **[Python | Weaviate](https://weaviate.io/developers/weaviate/client-libraries/python#usage)** > > Utilize the Python client library to access Weaviate and streamline data processes. Regards, Mohamed Shahin, Weaviate Support ---
**Author:** ![Tejas\_Sharma](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/tejas_sharma/32/2086_2.png) [@Tejas\_Sharma](https://forum.weaviate.io/u/Tejas_Sharma)\ **Post date:** [January 17, 2025, 6:12pm UTC](https://forum.weaviate.io/t/getting-default-error-on-migration/9753/3 "2025-01-17T18:12:15Z")
Hey @Shahin , Thanks for the response. I did, but it prints no failed objects and it fails with that error without saying there were any failed objects. There are tenants for which there were failed objects, but for those after I re-run the script, it seems to work. ```auto def migrate_data(collection_src, collection_tgt): with collection_tgt.batch.fixed_size(batch_size=100) as batch: for q in tqdm(collection_src.iterator(include_vector=True)): batch.add_object(properties=q.properties, vector=q.vector["default"], uuid=q.uuid) if collection_tgt.batch.failed_objects: print('!! FAILED OBJECTS: ') for failed_object in collection_tgt.batch.failed_objects: print(failed_object) return True ``` Is this code correct for printing it out? ---
**Author:** ![Shahin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/shahin/32/8085_2.png) [@Shahin](https://forum.weaviate.io/u/Shahin)\ **Post date:** [January 18, 2025, 4:11pm UTC](https://forum.weaviate.io/t/getting-default-error-on-migration/9753/4 "2025-01-18T16:11:19Z")
Hey @Tejas_Sharma, I hope you’re having a great weekend! It might not be the best idea to check `failed_objects` in real-time during batch processing. It’s often safer to access them after the batch import finishes. Here’s an internal example I use when testing batching processes — you might find it helpful. You need to tweak it a little for your specific use case, but it should give you a good idea of how I approach the logic. ```auto def batch_upload(client, file_path, collection_name, batch_size=10): """ Batch upload data from a CSV file into the specified collection. """ if not client.collections.exists(collection_name): raise Exception(f"Collection '{collection_name}' does not exist. Cannot insert data.") failed_objects = [] try: with open(file_path, mode='r', encoding='utf-8') as file: csv_reader = csv.DictReader(file) # Normalize column headers csv_reader.fieldnames = [header.strip().lower() for header in csv_reader.fieldnames] with client.batch.fixed_size(batch_size=100, concurrent_requests=2) as batch: for i, row in enumerate(csv_reader): # Prepare object properties obj_properties = { "company_id": row.get("company_id", ""), "last_name": row.get("last_name", ""), "first_name": row.get("first_name", ""), "job_title": row.get("job_title", ""), "email_address": row.get("email_address", ""), "country": row.get("country", ""), "interaction_notes": row.get("interaction_notes", ""), } batch.add_object( properties=obj_properties, collection=collection_name ) print(f"Batch processing completed. {i + 1} objects added.") except Exception as e: raise Exception(f"Batch insertion failed: {e}") # Check for failed objects and reason behind to be printed out failed_objects = client.batch.failed_objects if failed_objects: print(f"Number of failed objects: {len(failed_objects)}") for i, failed_obj in enumerate(failed_objects, 1): print(f"Failed object {i}: {failed_obj}") else: print(f"All objects successfully inserted into '{collection_name}'.") ``` Try that and let me know Regards, Mohamed Shahin, Weaviate Support