[bluepizza]

It's surprisingly complex.

Connections are dropped all the time, and then your code, on both client and server, need to account for retries (will the reconnection use a cached DNS entry? how will load balancing affect long term connections?), potentially missed events (now you need a delta between pings), DDoS protections (is this the same client connecting from 7 IPs in a row or is this a botnet), and so on.

Regular polling great reduces complexity on some of these points.

[slau]

Long polling has nearly all the same disadvantages. Disconnections are harder to track, DNS works exactly the same for both techniques, as does load balancing, and DDoS is specifically about different IPs trying to DoS your system, not the same IP creating multiple connections, so irrelevant to this discussion.

Yes, WS is complex. Long polling is not much better.

I can’t help but think that if front end connections are destroying your database, then your code is not structured correctly. You can accept both WS and long polls without touching your DB, having a single dispatcher then send the jobs to the waiting connections.

[bluepizza]

My understanding is that long polling has these issues handled by assuming the connection will be regularly dropped.

Clients using mobile phones tend to have their IPs rapidly changed in sequence.

I didn't mention databases, so I can't comment on that point.

[sn0wtrooper]

If a connection is closed, isn't the browser's responsibility to solve DNS when you open it again?