should i use a database to store online users
i am building a chat app i am using socket io ,express js i am hesitant whether i should store the current online users in an array or store them in a database i thought of the first option because i don't wanna use alot of space from my database i am using mysql and most free options don't offer much storage these days + everytime a user logs in i would need to make a call to the database , also i am not sure if it's a good idea to store the users in an array what if i have 10k users i would have to loop over them if i want to find a specific user
10 Replies
if users on your chat app are generated by using for example a simple form just to pick a nickname then store only array.
if they have to persist throughout sessions (aka "log back in") then you'll need some sort of database
assuming you end up with array option, you can have it sorted and that way you'll be able to access every single one in O(logn) time by using binary search
or you could use a HashSet for even faster access.
@Mcpie they actually login (they have accounts)
use keydb/redis
i'll suggest using redis as this is not the kind of data that you would need to be persistant as much to use mysql
sounds good , i am a bit concerned with storing the data in my backend i am not sure if the storage provided by the platform where i 'll deploy my backend is enough which i don't know , is that a valid concern or should i just go ahead and starting implementing ?
Redis uses RAM beacouse is mainly used as a cache, i think it will use storage if RAM isnt enough, but storing sessions shouldn't take much spece, are you concerned from the space messages will take?
the messages will be stored on a mysql database , i am gonna store the online users in redis
As I said, if you are storing just user sessions and you don't plan having much traffic going on your chat app it should be ok
what if the traffic grows bigger say 10k users what i should do then
It shouldn't take much more than few kilobytes per session, in that case if your community grows you could plan for vps upgrade and making some revenue with it