googleapis/mcp-toolbox · error

unable to create pool: %w

Error message

unable to create pool: %w

What it means

The SingleStore connection pool could not be created during source Initialize — the DSN built from host/port/user/password/database was rejected or the server was unreachable.

Source

Thrown at internal/sources/singlestore/singlestore.go:73

	Host             string            `yaml:"host" validate:"required"`
	Port             string            `yaml:"port" validate:"required"`
	User             string            `yaml:"user" validate:"required"`
	Password         string            `yaml:"password" validate:"required"`
	Database         string            `yaml:"database" validate:"required"`
	QueryTimeout     string            `yaml:"queryTimeout"`
	ConnectionParams map[string]string `yaml:"connectionParams"`
}

// SourceConfigType returns the type of the source configuration.
func (r Config) SourceConfigType() string {
	return SourceType
}

// Initialize sets up the SingleStore connection pool and returns a Source.
func (r Config) Initialize(ctx context.Context, tracer trace.Tracer) (sources.Source, error) {
	pool, err := initSingleStoreConnectionPool(ctx, tracer, r)
	if err != nil {
		return nil, fmt.Errorf("unable to create pool: %w", err)
	}

	err = pool.PingContext(ctx)
	if err != nil {
		pool.Close()
		return nil, fmt.Errorf("unable to connect successfully: %w", err)
	}

	s := &Source{
		Config: r,
		Pool:   pool,
	}
	return s, nil
}

var _ sources.Source = &Source{}

// Source represents a SingleStore database source and holds its connection pool.

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Verify host, port, credentials and database in the source config
2. Confirm network reachability of the SingleStore server
3. Check TLS requirements and connectionParams values

When it happens

Trigger: Thrown at internal/sources/singlestore/singlestore.go:73 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/a6e278964228b144. Report an issue: GitHub.