Node.js 中监听 redis key 过期事件

It is in fact possible to listen to the “expired” type keyevent notification using a subscribed client to the specific channel and listening to its message event.

通过 subscribe client 可以监听 __keyevent@db__:expired 频道来接收过期的事件。

const redis = require('redis');
const CONF = {db:3};
var pub, sub;
//.: Activate "notify-keyspace-events" for expired type events
pub = redis.createClient(CONF);
pub.send_command('config', ['set','notify-keyspace-events','Ex'], SubscribeExpired);
//.: Subscribe to the "notify-keyspace-events" channel used for expired type events
function SubscribeExpired(e,r){
    sub = redis.createClient(CONF);
    const expired_subKey = '__keyevent@'+CONF.db+'__:expired'
    sub.subscribe(expired_subKey,function(){
    console.log(' [i] Subscribed to "'+expired_subKey+'" event channel : '+r);
    sub.on('message',function (chan,msg){
        console.log('[expired]',msg);
　　 })
    TestKey();
 　　})
}
//.: For example (create a key & set to expire in 10 seconds)
function TestKey(){
    pub.set('testing','redis notify-keyspace-events : expired')
    pub.expire('testing',10)
}