TCP libp2p port not responding at times about nimbus-eth2 HOT 6 CLOSED

Doesn't seem related to max peers limit to me:

[email protected]:~ % s cat beacon-node-mainnet-stable-01 | grep -e max-peers -e metrics-port -e tcp-port   
    --tcp-port=9000 \
    --max-peers=320 \
    --metrics-port=9200 \
[email protected]:~ % sudo nmap -Pn -p9000 localhost                                                        
Starting Nmap 7.80 ( https://nmap.org ) at 2023-06-12 08:54 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up.

PORT     STATE    SERVICE
9000/tcp filtered cslistener

Nmap done: 1 IP address (1 host up) scanned in 2.12 seconds
[email protected]:~ % curl -s 0:9200/metrics | grep '^libp2p_peers '                                        
libp2p_peers 25.0

Clearly not at a limit, and the port seems unresponsive to TCP handshakes.

from nimbus-eth2.

#5102 seems to have fixed this for good, please re-open if it happens again

from nimbus-eth2.

The node stops accepting new connections when it is full

from nimbus-eth2.

Okay:

1. What do you mean by "full"? Are you referring to max peers limit? Because I've seen this on nodes that are not at limit.
2. What do you mean by "stops accepting new connections"? Do you mean they reject connections or just ignore them?

from nimbus-eth2.

Yes, once they reach --max-peers, they will ignore connections (to be more precise, they won't call accept, so it will be queued in the kernel as long as the other side is happy to wait, most probably will timeout after a while)
Though, if you've seen it on nodes which are not at their limit, that might be an actual issue

from nimbus-eth2.

Probable fix: status-im/nim-libp2p#916

from nimbus-eth2.