node.js - Is it possible to restart NodeJS + socket.io with 0 downtime? -


i running game server using pm2 managing app, messed around cluster mode:

pm2 start app.js -i max pm2 reload

and suppose downtime around 0, sockets got disconnected nevertheless. can't use 

{reconnection: true}

for clients there important things saved on dead sockets , on server itself, data lost crash browser.

everytime need update server js files clients connection lost , that's bad.

taking server down (or restarting) cause data loss items in memory. nodejs might fast in restarting, scripts , objects states lost.

a strategy two-fold: 1) store client information in database, maybe cache db redis or can persist when server restarts. each client have session token identifies them , data wish keep client. 2) store session identifier on connection when client connects server. when client (automatically) reconnects, must go through sequence a) re-establish session b) re-join socket.io room c) restore state (or missed updates).


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