SQLSTATE[HY000] [1040] Too many connections

Typecho\Db\Adapter\ConnectionException: SQLSTATE[HY000] [1040] Too many connections in /app/var/Typecho/Db/Adapter/Pdo.php:62 Stack trace: #0 /app/var/Typecho/Db.php(218): Typecho\Db\Adapter\Pdo->connect(Object(Typecho\Config)) #1 /app/var/Typecho/Db.php(301): Typecho\Db->selectDb(1) #2 /app/var/Widget/Options.php(147): Typecho\Db->select() #3 /app/var/Typecho/Widget.php(155): Widget\Options->execute() #4 /app/var/Typecho/Widget.php(187): Typecho\Widget::widget('Widget\\Options', NULL, NULL, true) #5 /app/var/Widget/Init.php(82): Typecho\Widget::alloc() #6 /app/var/Typecho/Widget.php(155): Widget\Init->execute() #7 /app/var/Typecho/Widget.php(187): Typecho\Widget::widget('Widget\\Init', NULL, NULL, true) #8 /app/index.php(17): Typecho\Widget::alloc() #9 {main}