yiisoft/yii2 · error · yii\base\InvalidConfigException

None of the master DB servers is available.

Error message

None of the master DB servers is available.

What it means

Error "None of the master DB servers is available." thrown in yiisoft/yii2.

Source

Thrown at framework/db/Connection.php:622

    /**
     * Establishes a DB connection.
     * It does nothing if a DB connection has already been established.
     * @throws Exception if connection fails
     */
    public function open()
    {
        if ($this->pdo !== null) {
            return;
        }

        if (!empty($this->masters)) {
            $db = $this->getMaster();
            if ($db !== null) {
                $this->pdo = $db->pdo;
                return;
            }

            throw new InvalidConfigException('None of the master DB servers is available.');
        }

        if (empty($this->dsn)) {
            throw new InvalidConfigException('Connection::dsn cannot be empty.');
        }

        $token = 'Opening DB connection: ' . $this->dsn;
        $enableProfiling = $this->enableProfiling;
        try {
            if ($this->enableLogging) {
                Yii::info($token, __METHOD__);
            }

            if ($enableProfiling) {
                Yii::beginProfile($token, __METHOD__);
            }

            $this->pdo = $this->createPdoInstance();

View on GitHub (pinned to 66f00d18a2)

When it happens

Trigger: Thrown at framework/db/Connection.php:622 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of yiisoft/yii2@66f00d18a2 (2026-08-17). Data as JSON: /api/errors/cc30fd836a6222c9. Report an issue: GitHub.