问题
I set quite a few server-side timeouts with setTimeout and setInterval for each connected user that can last for 10-30 seconds. If the Node.js instance restarts in the middle of one of these timeouts, they are obviously all cleared on restart, which can cause some issues for these users. How would I go about persisting these timeouts, or are there any modules that already help with this?
回答1:
I would store the start times and durations in Redis and restart incomplete timers when your application reloads. Some Redis modules:
https://github.com/joyent/node/wiki/modules#wiki-db-nosql-redis
回答2:
setTimeOut takes delay as parameter, so when setting timeout, capture 'currentServerTime + delay' say 'serverTriggerTime' and persist this in DB. Then, on restart of server, create the same timer using the serverTriggerTime.
Then, delay = serverTriggerTime - currentServerTime, use this delay to set new timer.
When setting timer
const date = Date.now();
const serverTriggerTime = +date + +delay; //time in milliseconds
On server restart:
serverTriggerTime = //retrieve from DB.
newDelay = serverTriggerTime - Date.now();
Also, set new timer only if newDelay >= 0, meaning the trigger time has not reached and will happen after newDelay time.
来源：https://stackoverflow.com/questions/11454587/persist-settimeout-and-setinterval-across-node-js-restarts