-一個簡單的數(shù)據(jù)緩存解決方案

    最近做了一個聊天室系統(tǒng)，系統(tǒng)有N個聊天室，在并發(fā)量很大的情況下，如果用戶聊天記錄直接寫入MySql的話，對數(shù)據(jù)庫的沖擊會很大。這里我寫了個簡單的解決方案：聊天數(shù)據(jù)先存入redis的隊列中，然后用crontab每隔1分鐘執(zhí)行PHP腳本，把數(shù)據(jù)從redis隊列中“批量”移到mysql。當有多條插入語句時，把數(shù)據(jù)拼裝成1條insert語句，減少數(shù)據(jù)庫的操作次數(shù)。

1. 配置文件 config.php

<?php

function dbMessageConfig(){

    //用戶信息庫表的配置

return array(

        'database_type' => 'mysql',

        'database_name' => 'test',

        'server' => '127.0.0.1',

        'username' => 'root',

        'password' => 'root',

        'charset' => 'utf8'

);

}

function redisCacheConfig(){

return array(

        'ip' => '127.0.0.1',

        'port' => '6379',

        'password' => '888888'

);

}

2. redis2mysql.php

<?php

error_reporting(E_ALL^E_NOTICE^E_WARNING);

require_once dirname(__FILE__).'/config.php';

$dbMessage = dbMessageConfig();

$configRedis = redisCacheConfig();

$r = new \Redis();

$r->connect($configRedis['ip'], $configRedis['port']);

$r->auth($configRedis['password']);

//獲取redis中的消息

$message = $r->rpop('chat_message');

$tenantArr = array();

if(!empty($message)){

    $tmpArr = explode(':', $message);

    $tenant_id = $tmpArr[0];

    if(!empty($tenant_id) && is_numeric($tenant_id)){

    if(!empty($tmpArr[1])) $tenantArr[$tenant_id] = $tmpArr[1];

}

}

//一次最多取20條記錄

$MAX_NUM = 20;

$index = 1;

while(!empty($message) && $MAX_NUM > $index){

    $message = $r->rpop('chat_message');

    //echo $message;

    $tmpArr = explode(':', $message);

    $tenant_id = $tmpArr[0];

    if(!empty($tenant_id) && is_numeric($tenant_id)){

    if(!empty($tmpArr[1])){

    if(array_key_exists($tenant_id, $tenantArr)){

    $tmp = $tenantArr[$tenant_id];

$tmp = $tmp.",".$tmpArr[1];

$tenantArr[$tenant_id] = $tmp;

}else{

    $tenantArr[$tenant_id] = $tmpArr[1];

}

}

}

$index = $index + 1;

}

$table_message = 'chat_message';

$dbh = new \PDO('mysql:host='.$dbMessage['server'].';dbname='.$dbMessage['database_name'], $dbMessage['username'], $dbMessage['password']);

$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);    

$dbh->exec('set names '.$dbMessage['charset']);

foreach ($tenantArr as $tenant_id=>$sql) {

$sqlstr = 'insert INTO '.$table_message.'_'.$tenant_id.' VALUES '.$sql.';';

    $stmt = $dbh->prepare($sqlstr);  

    $stmt->execute();

}

3. 配置crontab

*/1 * * * * /opt/php/bin/php -f /usr/local/php/redis2mysql.php >/dev/null 2>&1

啟動crontab：/sbin/service crond start

4. 寫入redis的sql語句（java代碼）：

//把chatmessage發(fā)送到redis儲存

Jedis redis = RedisUtil.getJedis();

String key="message";

StringBuffer strMsg = new StringBuffer(tenant_id);

strMsg.append(":(NULL,");

strMsg.append(room_id);

strMsg.append(",");

strMsg.append(uid);

strMsg.append(",'");

strMsg.append(username);

strMsg.append("',");

strMsg.append(user_type);

strMsg.append(",'");

strMsg.append(avatar);

strMsg.append("','");

strMsg.append(content);

strMsg.append("',");

strMsg.append(add_time);

strMsg.append(",1)");

redis.lpush(key, strMsg.toString());

參考：

⑴ crontab啟動 、運行和編輯查看

http://blog.csdn.net/ariessurfer/article/details/7459183

⑵ crontab定時任務配置

http://www.cnblogs.com/kerrycode/p/3238346.html

⑶ php mysql PDO使用

http://blog.csdn.net/qq635785620/article/details/11284591