This is my second iterations for this project which I tried on day 2
I tried to do the first one with a noSql database which stores message and sort them with timestamp.
The second solution is based on rabbiMq messaging server which I found quite a perfect suite for this
The http server keeps track of subscriptions in memory and creates a queue for each subscription.
There is lot of cases which needs to handled
1) Configure rabbitQ limits and scale it with per node
2) There is limited memory for the webserver and we might have to put the subscription data base in database
A good choice will be a in memory data base like redis which automatically has scaling and clustering
3)More error conditions checking require I did basic test but not a high load test
4) There is need of lot of exception handling in the code which might blow the server up
5) the http server is multithreaded so it should take care of parrallel connections but I did not
do a load testing on it.
6) The part is 8080 for the http server and current code does not retry connection or another port