APP
場景
在一些電商項目中，對一些過期的訂單以及優(yōu)惠券等業(yè)務(wù)需要做后續(xù)處理
方案
- 定時掃描數(shù)據(jù)庫，通過掃描到符合條件的數(shù)據(jù)做特定處理（成本高）
- 通過redis的監(jiān)聽訂閱做處理（成本低）
實踐準備
- 開啟事件通知，redis 版本大于 2.8，修改配置文件
- 需要訂閱主題（__keyevent@dbindex__:expired）,dbindex指的是數(shù)據(jù)庫索引，redis有16個小數(shù)據(jù)庫，一般存儲到的是0號數(shù)據(jù)庫，所以訂閱的主題可以是__keyevent@0__:expired
?修改redis配置文件
# notify-keyspace-events Ex //復(fù)制本行
#
# By default all notifications are disabled because most users don't need
# this feature and the feature has some overhead. Note that if you don't
# specify at least one of K or E, no events will be delivered.
#notify-keyspace-events “” //注釋此行
notify-keyspace-events Ex //新寫一行
############################### GOPHER SERVER #################################
修改完重啟redis服務(wù)
php代碼
//redis類
class RedisClient
{
private $redis;
public function __construct($host = '127.0.0.1', $port = 6379)
{
$this->redis = new Redis();
$this->redis->connect($host, $port);
}
public function setex($key, $time, $val)
{
return $this->redis->setex($key, $time, $val);
}
public function set($key, $val)
{
return $this->redis->set($key, $val);
}
public function get($key)
{
return $this->redis->get($key);
}
public function expire($key = null, $time = 0)
{
return $this->redis->expire($key, $time);
}
public function psubscribe($patterns = array(), $callback)
{
$this->redis->psubscribe($patterns, $callback);
}
public function setOption()
{
$this->redis->setOption(Redis::OPT_READ_TIMEOUT, -1);
}
}
//過期事件訂閱
require_once './RedisClient.class.php';
$redis = new RedisClient();
// 解決Redis客戶端訂閱時候超時情況，永久支持
$redis->setOption();
$redis->psubscribe(array('__keyevent@0__:expired'), 'keyCallbackFunc');
// 回調(diào)函數(shù)
function keyCallbackFunc($redis, $pattern, $chan, $msg)
{
echo "Pattern: $pattern ";
echo "Channel: $chan ";
echo "Payl
oad: $msg ";
//keyCallbackFunc為訂閱事件后的回調(diào)函數(shù)，寫業(yè)務(wù)處理邏輯部分，后續(xù)業(yè)務(wù)處理
}
//來一個測試key
require_once './RedisClient.class.php';
$redis = new RedisClient();
$cache_key = "order_id:"
$order_id = $cache_key.123456;
$redis->setex('123456’,5,$order_id);
先phpcli模式執(zhí)行訂閱，然后進行setkey測試
監(jiān)聽到過期的key，那么可以字符串分離拿到對應(yīng)的order_id做后續(xù)處理
?
本文摘自 ：https://blog.51cto.com/u
