3 ms·
Fantastic! I'm particularly excited about the retransmit tracepoints, as troubleshooting some of these issues on systems that can't afford the tcpdump overhead
by gregdunn 9y ago
Fantastic!
I'm particularly excited about the retransmit tracepoints, as troubleshooting some of these issues on systems that can't afford the tcpdump overhead has caused me significant headache in the past.
- fulafel 9y agoI'm sure you found these too, but your comment made me want to refresh my memory: For older kernels, there is a ftrace way for tracing retransmits: http://www.brendangregg.com/blog/2014-09-06/linux-ftrace-tcp-retransmit-tracing.html http://www.brendangregg.com/blog/2014-09-06/linux-ftrace-tcp... The oldest are SNMP style counters used by "netstat -s" / "sar -n ETCP" for all retransmits on the system, if you don't need per flow stats. Ten there's an application level getsockopt TCP_INFO, detailed at: https://linuxgazette.net/136/pfeiffer.html https://linuxgazette.net/136/pfeiffer.html