SQL Always On Read-Only Routing Configuration for VS Code
Configure SQL Server Always On Availability Group read-only routing without leaving VS Code. This is a port of the Denny Cherry & Associates Consulting AlwaysOn Tools (originally a VB.NET WinForms app) to a VS Code extension.
Features
- Connect to a SQL Server instance — an Availability Group listener or directly to the primary replica.
- Browse Availability Groups and their replicas in a tree view in the activity bar.
- Configure a replica's read-only routing list (the priority-ordered list of partner replicas) with a checkable, reorderable editor.
- Configure a replica's read-only routing URL (
TCP://fqdn:port).
- Generate the T-SQL
ALTER AVAILABILITY GROUP script or apply it directly to the server.
- Optional load-balanced (round-robin) routing list on SQL Server 2017+.
The tool validates on connect that the instance is SQL Server 2012+ with HADR enabled, mirroring the original application.
Requirements
This extension depends on the Microsoft SQL Server (ms-mssql.mssql) extension (declared via extensionDependencies), so VS Code installs and enables it automatically. It provides the connection dialog and the connection-sharing API that lets this extension reuse your existing connections for every authentication type without re-authenticating.
Authentication
All authentication modes the original supported, plus Microsoft Entra:
| Mode |
Notes |
| SQL Server Authentication |
User name + password |
| Windows Authentication |
NTLM — enter the account as DOMAIN\user + password |
| Microsoft Entra - Password |
Azure AD user + password |
| Microsoft Entra - Integrated |
Uses the signed-in Azure identity (no credentials) |
Windows authentication uses NTLM (cross-platform via the tedious/mssql driver), so a DOMAIN\user and password are required rather than the desktop's true integrated SSPI. The server rejects any auth mode it does not support.
Passwords are stored in the VS Code SecretStorage; server profiles are stored in global state.
Usage
- Open the Always On Read-Only Routing view in the activity bar.
- Click Connect to a Server. This reuses the SQL Server extension's connection picker (select an existing connection or create a new one) so the experience matches that extension. When you pick a saved connection, the routing tool reuses the SQL Server extension's own connection (via the connection-sharing API), so all authentication types work — including Windows-integrated and Entra-MFA — with no re-authentication. A brand-new connection that isn't saved yet falls back to this extension's own engine (SQL and Entra-password). (A built-in prompt fallback also exists as a safety net if the SQL Server extension is ever unavailable.)
- Expand the server → Availability Group → replica.
- Right-click a replica:
- Configure Read-Only Routing List… — opens the routing-list editor.
- Configure Read-Only Routing URL… — sets the
TCP:// routing URL.
SQL Server extension integration
If the Microsoft SQL Server (ms-mssql.mssql) extension is installed, right-click a connected server in its Object Explorer and choose "Configure Always On Read-Only Routing…". This opens a guided flow (Availability Group → replica → routing list / routing URL).
This reuses the SQL Server extension's own existing connection through its public connection-sharing API — so no credentials are re-entered, including Windows-integrated and Entra MFA connections that this extension cannot establish on its own. The first time, the SQL Server extension asks you to approve connection sharing with Always On Read-Only Routing.
Notes:
- The menu hook relies on the SQL Server extension's internal node
contextValue (type=Server), which is not a documented API and could change in a future release of that extension.
- Connection sharing requires a reasonably recent version of the SQL Server extension (the
connectionSharing API). If it is unavailable, use Always On Read-Only Routing: Connect to a Server in the Always On Read-Only Routing view instead.
Development
npm install
npm run compile # or: npm run watch
Press F5 in VS Code to launch an Extension Development Host.
Package a .vsix with:
npx vsce package
About DCAC
DCAC (Denny Cherry & Associates Consulting) is a Microsoft data-platform consulting firm. We help organizations design, secure, migrate, and operate mission-critical SQL Server and Azure environments — covering high-availability architectures such as Always On Availability Groups, performance tuning, data security and compliance, cloud migration, and 24×7 managed database services.
License
MIT
