Sometimes there is a spam attack on the IOTA network where there are up to 2000 transactions per minute where normally we only have 50 t/m. I know that the spam makes the tangle even stronger, but I also heard of many full nodes that had to close because of such a spam attack. Now I wonder what is the worst case that could happen if let say all mining farms come together and spam against the tangle.
The main two bottlenecks on the tangle are as follows:
1) The coordinator: currently, the tangle has a coordinator that ensures that the network isn't overwhelmed by a malicious attacker. Due to the coordinator, there is a limit on transactions per second which can cause slowdowns. Once the network is mature enough, the coordinator will be removed and slowdowns will occur less often.
2) The balance of load on all of the nodes: IOTA scales theoretically infinitely as transactions propagate themselves and confirm each other. However, on current tests most nodes can only handle about 1000 tp/s each. So, if people aren't spreading out their transactions to nodes but are instead overloading a single node, such as how the spammer websites worked, it can slow down the tangle as one node builds up a big backlog and other nodes are dormant and unused.
If these two issues are solved, mining farms coming together to spam the tangle is actually a good thing and should speed up the network, not a worst case at all.