class/Db.php

public function __construct($dbarr)
{
    $this->dbarr = $dbarr;
    $tmpstr = $dbarr['pconnect'] ? 'p:' : ''; // 持久化连接
    try {
        $this->conn = new mysqli($tmpstr . $dbarr['host'], $dbarr['user'], $dbarr['pass'], $dbarr['name']);
        if ($this->conn->connect_error) {
            throw new Exception('Connection failed: ' . $this->conn->connect_error);
        }
        $this->conn->set_charset('utf8');
    } catch (Exception $e) {
        // 捕获连接错误并输出错误信息
        error_log($e->getMessage());  // 记录日志
        die("Database connection failed. Please try again later.");
    }
}

修改配置文件启用持久化

$dbarr = [
     'host' => ''
    ,'port' => ''
    ,'name' => ''
    ,'user' => ''
    ,'pass' => ''
    ,'pconnect' => true  // 启用持久化连接
];