Fix tcp/connection/accepted|initiated metrics for kernel 5.10 #266
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* Add TCP Tail Loss Recovery Probes sampler via BPF * Add TCP Retransmit timeout sampler via BPF
WUMUXIAN
commented
Jan 5, 2022
| @@ -206,7 +206,7 @@ impl TcpStatistic { | |||
| name: "tcp_finish_connect".to_string(), | |||
| handler: "trace_finish_connect".to_string(), | |||
| probe_type: ProbeType::Kernel, | |||
| probe_location: ProbeLocation::Return, | |||
| probe_location: ProbeLocation::Entry, | |||
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On Kernel 5.4, it does not matter if we attach this at Entry or Return.
However on Kernel 5.10, if we attach it to Return, the sock* sk can't be used to get the stats from the map as the address are moved 128 bits. Now sure about why.
But using Entry here fix the issue.
WUMUXIAN
changed the title
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Problem
We have deployed Rezolus 2.15 on T3 canary instances and it showed that
tcp/connection/accepted
tcp/connection/initiated
are not working
I upgraded my VM to the same kernel version as T3 instances and confirmed that these two metrics stops working on kernel 5.10.
Solution
Made changes to the code to make sure these two metrics are compatible to 5.10.
Result
The two metrics work correctly on my 5.4 kernel as well as 5.10 kernel now.