2 prosody in jitsi meet

is there really exist 2 prosody?
one for client and jicofo
other for jvb nd prosody???

In a standard installation, there will only be 1 prosody server.

However, to support really large meetings it is technically possible to configure 2 prosody servers to spread the load – one to handle client events as usual, and the other to handle JVBs. From what I’ve read, this is not straight-forward to get right. I have never tried it. I believe this is what is done for meet.jit.si which is why they can handle 500 participants in one meeting (and much much more soon).

In most use case when deployments need to handle large numbers of meetings (rather than really really large meetings), one would typically just scale up the number of shards and JVBs per shard, and optimise Prosody performance.