Pipeline runs issue

@Stephen

Upgrading from Version 1 to Version 2 linked services in Azure Data Factory (ADF) to address connection failures requires careful planning to ensure a smooth transition and avoid pipeline disruptions. Below are key considerations, potential issues to be cautious about, and guidelines for the upgrade process, tailored to your scenario with two linked service connection failures.

Version 2 connectors often have improved performance, enhanced security, and support for newer versions of data sources (e.g., MySQL 8.1, 8.2 for version 2 vs. 5.6, 5.7, 8.0 for version 1). However, they may have different data type mappings, authentication methods, or configuration requirements compared to Version 1. For example, MySQL connector version 2.0 uses different data type mappings, which could affect data integrity if not handled properly.

Many Version 1 connectors are at the End of Support stage, meaning no bug fixes or new features are provided, and Microsoft may disable them if critical security vulnerabilities are found. For example, the MySQL connector version 1.0 is set to be disabled after September 30, 2025, after which pipelines using it will fail.
Your current connection failures may stem from authentication issues, network configurations, firewall settings, or deprecated features in Version 1 connectors. For example, common errors include "The underlying connection was closed" due to authentication failures or invalid queries for ODBC connectors.
Before upgrading, diagnose the root cause of the connection failures. Upgrading to Version 2 may not resolve issues related to network connectivity, firewall rules, or incorrect credentials. For instance, if connecting to an on-premises SQL Server, ensure the Self-Hosted Integration Runtime (SHIR) is properly configured and firewall ports (e.g., 1433, 443) are open.
Version 2 connectors often support modern authentication methods like OAuth2, managed identities, or Azure Key Vault for storing secrets, which are more secure than Version 1’s reliance on connection strings or SQL authentication.
Upgrading a linked service to Version 2 requires updating all dependent datasets and pipelines to reference the new linked service. This can be time-consuming if you have many related objects.
Some Version 2 connectors require specific integration runtimes (e.g., Azure IR with managed virtual network for public access or SHIR for private access). For instance, connecting to a PostgreSQL instance with private access requires a SHIR.

Upgrading from Version 1 to Version 2 linked services in ADF can resolve connection issues caused by deprecated connectors and improve security and performance. Be cautious about connector differences, authentication changes, and impacts on existing pipelines. Follow the guidelines above to diagnose current failures, inventory dependencies, test in a non-production environment, and deploy carefully. If you provide details about the data sources or error messages for the failing linked services, I can offer more specific advice.