swoole框架栏目介绍swoole实现mysql连接池的方法
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前言传统的nginx+fpm模式的php程序而言，每次请求fpm的worker都会连接一次mysql，然后请求结束便会断开连接。对于并发小的应用来说这不会有什么问题，但是对于高并发的应用来说，频繁建立连接connect和销毁连接close，数据库便会成为瓶颈，相信不少人也遇到过to many connection的mysql报错吧。
连接池的优势连接池采用的是长连接模式，会一直保持与mysql的连接，用完后会重新放回连接池，从而节省了建立连接和断开连接的消耗，大大降低了系统io的消耗，一定程度上提高了程序的并发性能。如果连接池空闲，就从连接池分配一个连接，否则，请求将被加入到等待队列中。
实现我们采用swoole实现mysql连接池
连接池类<?phprequire_once "mysqldb.php";class mysqlpool{ private static $instance; private $pool; private $config; private $pool_get_timeout; /** * 获取mysql进程池单例 * @param null $config * @return mysqlpool */ public static function getinstance($config = null) { if (empty(self::$instance)) { if (empty($config)) { throw new runtimeexception("mysql config is empty"); } self::$instance = new static($config); } return self::$instance; } public function __construct($config) { if (empty($this->pool)) {            $this->config = $config;            $this->pool = new \swoole\coroutine\channel($config['pool_size']);            for ($i = 0; $i < $config['pool_size']; $i++) { \go(function() use ($config) { $mysql = new mysqldb(); $res = $mysql->connect($config['mysql']);                    if ($res === false) {                        throw new runtimeexception(failed to connect mysql server);                    } else {                        $this->pool->push($mysql);                    }                });            }        }    }    public function get()    {        if ($this->pool->length() > 0) {            $mysql = $this->pool->pop($this->config['pool_get_timeout']);            if (false === $mysql) {                throw new runtimeexception(pop mysql timeout);            }            return $mysql;        } else {            throw new runtimeexception(pool length <= 0"); } } public function recycle(mysqldb $mysql){ $this->pool->push($mysql);    }    /**     * 获取连接池长度     * @return mixed     */    public function getpoolsize(){        return $this->pool->length();    }}
数据库db类<?phpclass mysqldb{ private $connection; public function connect($config) { $connection = new \swoole\coroutine\mysql(); $res = $connection->connect($config);        if ($res === false) {            throw new runtimeexception($connection->connect_error, $connection->errno);        } else {            $this->connection = $connection;        }        return $res;    }    public function query($sql){        $result = $this->connection->query($sql);        return $result;    }}
在http协程服务器中创建连接池<?phprequire_once "mysqlpool.php";\co\run(function () { $server = new \co\http\server("0.0.0.0", 9501, false); $pool = mysqlpool::getinstance([ 'pool_size'=>5,        'pool_get_timeout'=>1,        'timeout'=>1,        'charset'=>'utf8',        'strict_type'=>false,        'fetch_mode'=>true,        'mysql'=>[            'host'=>'127.0.0.1',            'port'=>'3306',            'user'=>'homestead',            'password'=>'secret',            'database'=>'blog',        ]    ]);    $server->handle('/', function ($request, $response) use ($pool){        $mysql = $pool->get();        $res = $mysql->query(select id,phone,username from user limit 1);        var_dump($res);        $pool->recycle($mysql);        $response->end(<h1>test</h1>);    });    $server->handle('/test', function ($request, $response) {        $response->end(<h1>test</h1>);    });    $server->handle('/stop', function ($request, $response) use ($server) {        $response->end(<h1>stop</h1>);        $server->shutdown();    });    $server->start();});
源码地址 swoole-mysql-pool相关免费学习推荐：mysql视频教程
以上就是详解基于swoole的mysql连接池实现的详细内容。