Summary

There exists significant difficulties with regards to the upgrading of a large set of MARC authority records when mapping rule changes have been applied, as well as migrating authority records from other systems to FOLIO.  Updating authority records to apply mapping rules changes is a time-consuming process that takes multiple days, and using DI does not scale well when libraries are attempting to do other work with data import. Failure to update these records leads to data inconsistency. With the implementation of authority control/linking (manual) with Orchid, this issue may become even more problematic for libraries. As automated linking is introduced, this issue will become even more challenging.

The proposed solution addresses issues related to remapping and initial record migration in terms of data volumes and expected performance.

Requirements

Functional requirements

• The solution should not use data import, as the core issue lies in migrating a large volume of records. Data import is not designed to handle millions of records.
• Operate in the background without disrupting other FOLIO workflows, including data import.
• Support UTF-8 encoding.
• Support optimistic locking mechanism.
• Enforce data validation rules during the creation of MARC authority records to prevent duplicates.
• Apply the same data validation rules enforced during the updating of MARC authority records.
• Provide a response that includes details on records that failed to create or update in SRS and Inventory.
• Consider that it can be used for two types of migrations 
  • • migrating all authority records from one release to another (remapping)
    • migrating a library with over 500,000+ authority records to  FOLIO.
• For migration cases the import file format is MARC21
• A straightforward solution should be available to the user to obtain and analyze all errors.
• Users should have a simple solution to get/receive files that contain records with errors (The records that were not processed successfully).

ARCH-38 - Getting issue details... STATUS

ARCH-46 - Getting issue details... STATUS

Non-functional requirements

Following https://docs.google.com/spreadsheets/d/10GiFrfZee8aY8PcE0JJxf-lWtMkddFWnOYo_tiKYXrs/edit#gid=0

• The max number of records in the source file: 12 000 000+ records
  • Following the preliminary analysis of LoC the number of records could be more than 20 000 000+
• Processing should be almost linear
• Time spent on the migration of 10 000 MARC records: TBD
• Time spent on the remapping of 10 000 records: TBD

Assumptions

• This solution will be used by the administrative personnel and/or the hosting team, so the solution will not have UI forms (at least in the early stages) and will provide RESTful API only.
• The solution is expected to use all allocated resources to complete the import operation in the shortest possible time. However, there should be a configuration option to define how many resources should be allocated or how many concurrently running migration processes should be simultaneously.

Limitations

• The solution will use the default mapping profile for Authority records.
• The solution will not support the complex Data-Import like matching functionality to find records that should be updated. In the case of remapping, the matching will be done simply based on the primary key values (Ids).
• Running more than one import/remapping operation simultaneously is prohibited.
• For the sake of simplicity and fault tolerance, all file operations will be done outside of the solution.

Side effects

• The remapping operation will trigger the Authority reindexing automatically, so a separate authority reindexing will not be needed.

Implementation

The solution will be implemented as a separate FOLIO module.

The main idea is that processing large volumes of data could be done in two separate steps.
The first step is to read data from the source file or database, apply new mapping rules (using the existing data-import-processing-core library), and store the resulting entities in the file.
The next step is to deliver the file with entities to the appropriate back-end module and store them in the database one by one using the existing update implementation.

Notes

• In order to support significant volumes of data, the Data Access Layer should be implemented using plain JDBC; Spring Data can't be used because of high memory consumption for such volumes of data and lower performance compared to the plain JDBC approach.

API

This module will provide the following RESTful  endpoints:

• start import/remapping operations
• check import/remapping operations status
• get operation errors

High-level operations overview

Detailed Sequence diagrams representing the Import and Remapping operations

ER diagram for the data model.

High-level component diagram