[bbrazil]

By default you can only get that per-kernel from /proc/net/netsnmp. BPF may allow something more granular.

The other way of approaching it is to look for the additional latency it causes, which you can spot on a per-service basis.

[saravana87]

Additional latency could be an indicator, but there's no guarantee that it is because of retransmissions ?

[bbrazil]

If you look at your latency histogram and are seeing a bump at around 200ms above normal (which was the default minimum wait time a few years back anyway), it's probably retransmits.

[saravana87]

Got it.