OpenDHT response time limits and DoS protection

[abitrolly]

When working with IPFS I always wondered what is the limit for how much data can be stored in DHT and how does it respond when somebody tries to flood the system?

[aberaud]

OpenDHT is not designed to store large amount of data, nor to store data on long term.
Values typically expire after 10 minutes and have a maximum size of 64k (recommended max 16k).
OpenDHT maintains a per-IP storage quota, and when a node storage (always in-memory, default limit 64MB) is full, the oldest values from the IP using the most storage are dropped to store new values.

[abitrolly]

With 16k it is 4000 records per IP to hit 64Mb limit. If 23595 bitcoin nodes decide to fill each quota to the max, it will take 1.5TB

What happens if the node has only 256Gb of memory, and the memory limit is reached, because too many nodes are connected, and per-IP quota for each IP is within 64MB boundary?

[aberaud]

64MB limit is global for the node, not per IP or peer.

[twdragon]

@abitrolly it seems impossible to prepare a memory bomb inside the cell, so in the worst case the kernel will kill the process