[Bug]: when using `--mcp-stdio` failure with "logging/setlevel"

[JerryNixon]

What?

We get the error Method not found: logging/setLevel when our MCP Server (STDIO) starts.

Incoming request to our MCP

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "logging/setLevel",
  "params": {
    "level": "info"
  }
}

The problem

DAB already advertises the logging capability in its initialize response (see line 189), but the server's request dispatch loop has no handler for "logging/setLevel", so the client gets a JSON-RPC Method not found (-32601) error back.

data-api-builder/src/Azure.DataApiBuilder.Mcp/Core/McpStdioServer.cs

Lines 188 to 199 in 9563a20

	tools = new { listChanged = true },
	logging = new { }
	},
	serverInfo = new
	{
	name = McpProtocolDefaults.MCP_SERVER_NAME,
	version = McpProtocolDefaults.MCP_SERVER_VERSION
	},
	instructions = !string.IsNullOrWhiteSpace(instructions) ? instructions : null
	};
	WriteResult(id, result);

The solution

1. CLI --LogLevel — takes highest precedence (IsCliOverriddenflag inDynamicLogLevelProvider`)
2. Config runtime.host.logging.level — second precedence
3. MCP logging/setLevel — lowest precedence, should only apply if CLI didn't override

Then, add a case in the switch and route it through the existing DynamicLogLevelProvider.

Note

If IsCliOverridden is true, accept the request but silently ignore it — the client shouldn't get an error, but CLI wins.

Why?

This is the mcp.json file in the /.vscode folder.

{
	"servers": {
		"dab-todo-test-mcp": {
			"type": "stdio",
			"command": "dab",
			"args": [
				"start",
				"--mcp-stdio",
				"role:anonymous",
				"--LogLevel",
				"none",
				"--config",
				"${workspaceFolder}/dab-config.json"
			]
		}
	},
	"inputs": []
}

When starting the MCP Server, the client passes in:

But we do not support it, so we get:

Method not found: logging/setLevel

[anushakolan]

Version 1.7

[anushakolan]

The config-based log level is set under runtime then telemetry then log-level, not under runtime then host then logging. This is because log levels are part of telemetry and observability settings in DAB's config schema, not server hosting settings.

Precedence from highest to lowest:

CLI LogLevel flag - cannot be changed
Config telemetry log-level - cannot be changed by MCP
MCP logging setLevel - only works if neither CLI nor config set a level
MCP can only change the log level dynamically if the user did not explicitly configure one through the CLI or config file.

[anushakolan]

"telemetry": {
  "log-level": {
    "default": "Warning"
  }
},