Collect additional TcpExt metrics#10844
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Number of martian packets dropped by the reverse path filter: IPReversePathFilter I've used `system.net.ip.reverse_path_filter` as the metric name for this one as even if it's under TcpExt, it has absolutely nothing to do with the TCP layer. Prune TCP queue metrics: PruneCalled, RcvPruned and OfoPruned netstat defines PruneCalled as '%u packets pruned from receive queue because of socket' which is inexact. This metric will count the number of called to the tcp_prune_queue and doesn't necessarily drop packets if it manages to free enough space. Packets dropped by PAWS: PAWSActive and PAWSEstab PAWSActive is a confusing name. It's basically the number of dropped SYNACK packets by the PAWS mechanism. Active is probably for "active open", when the socket is in a SYN_SENT state. Using `system.net.tcp.paws_connection_drop` as the metric name for PAWSActive made more sense. Number of retransmitted SYN packets: TCPSynRetrans Number of socket closed due to a TCP timeout (maximum retransmission reached or keep-alive timeouts): TCPAbortOnTimeout 0win state changes: TCPFromZeroWindowAdv, TCPToZeroWindowAdv Syn cookies stats: SyncookiesSent, SyncookiesRecv, SyncookiesFailed Reused TW socket: TWRecycled. This can easily be confused with the `tcp_tw_recycle` sysctl option which doesn't exist anymore. In the kernel code, we can see it's incremented if the reuse part was successful (`twsk_unique(sk, sk2, twp)`) https://github.com/torvalds/linux/blob/19757cebf0c5016a1f36f7fe9810a9f0b33c0832/net/ipv4/inet_hashtables.c#L487-L490 So I've used `system.net.tcp.tw_reused` for this one which make a bit more sense.
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Number of martian packets dropped by the reverse path filter: IPReversePathFilter I've used `system.net.ip.reverse_path_filter` as the metric name for this one as even if it's under TcpExt, it has absolutely nothing to do with the TCP layer. Prune TCP queue metrics: PruneCalled, RcvPruned and OfoPruned netstat defines PruneCalled as '%u packets pruned from receive queue because of socket' which is inexact. This metric will count the number of called to the tcp_prune_queue and doesn't necessarily drop packets if it manages to free enough space. Packets dropped by PAWS: PAWSActive and PAWSEstab PAWSActive is a confusing name. It's basically the number of dropped SYNACK packets by the PAWS mechanism. Active is probably for "active open", when the socket is in a SYN_SENT state. Using `system.net.tcp.paws_connection_drop` as the metric name for PAWSActive made more sense. Number of retransmitted SYN packets: TCPSynRetrans Number of socket closed due to a TCP timeout (maximum retransmission reached or keep-alive timeouts): TCPAbortOnTimeout 0win state changes: TCPFromZeroWindowAdv, TCPToZeroWindowAdv Syn cookies stats: SyncookiesSent, SyncookiesRecv, SyncookiesFailed Reused TW socket: TWRecycled. This can easily be confused with the `tcp_tw_recycle` sysctl option which doesn't exist anymore. In the kernel code, we can see it's incremented if the reuse part was successful (`twsk_unique(sk, sk2, twp)`) https://github.com/torvalds/linux/blob/19757cebf0c5016a1f36f7fe9810a9f0b33c0832/net/ipv4/inet_hashtables.c#L487-L490 So I've used `system.net.tcp.tw_reused` for this one which make a bit more sense. 891c7dd
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Number of martian packets dropped by the reverse path filter: IPReversePathFilter I've used `system.net.ip.reverse_path_filter` as the metric name for this one as even if it's under TcpExt, it has absolutely nothing to do with the TCP layer. Prune TCP queue metrics: PruneCalled, RcvPruned and OfoPruned netstat defines PruneCalled as '%u packets pruned from receive queue because of socket' which is inexact. This metric will count the number of called to the tcp_prune_queue and doesn't necessarily drop packets if it manages to free enough space. Packets dropped by PAWS: PAWSActive and PAWSEstab PAWSActive is a confusing name. It's basically the number of dropped SYNACK packets by the PAWS mechanism. Active is probably for "active open", when the socket is in a SYN_SENT state. Using `system.net.tcp.paws_connection_drop` as the metric name for PAWSActive made more sense. Number of retransmitted SYN packets: TCPSynRetrans Number of socket closed due to a TCP timeout (maximum retransmission reached or keep-alive timeouts): TCPAbortOnTimeout 0win state changes: TCPFromZeroWindowAdv, TCPToZeroWindowAdv Syn cookies stats: SyncookiesSent, SyncookiesRecv, SyncookiesFailed Reused TW socket: TWRecycled. This can easily be confused with the `tcp_tw_recycle` sysctl option which doesn't exist anymore. In the kernel code, we can see it's incremented if the reuse part was successful (`twsk_unique(sk, sk2, twp)`) https://github.com/torvalds/linux/blob/19757cebf0c5016a1f36f7fe9810a9f0b33c0832/net/ipv4/inet_hashtables.c#L487-L490 So I've used `system.net.tcp.tw_reused` for this one which make a bit more sense.
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What does this PR do?
Collect additional TcpExt metrics
Motivation
We're lacking visibility to deep dive and troubleshoot complex network issues with datadog.
Additional Notes
Number of martian packets dropped by the reverse path filter: IPReversePathFilter
I've used
system.net.ip.reverse_path_filteras the metric name forthis one as even if it's under TcpExt, it has absolutely nothing to do
with the TCP layer.
Prune TCP queue metrics: PruneCalled, RcvPruned and OfoPruned
netstat defines PruneCalled as '%u packets pruned from receive queue because of socket' which is inexact.
This metric will count the number of called to the tcp_prune_queue and
doesn't necessarily drop packets if it manages to free enough space.
Packets dropped by PAWS: PAWSActive and PAWSEstab
PAWSActive is a confusing name. It's basically the number of dropped
SYNACK packets by the PAWS mechanism. Active is probably for "active
open", when the socket is in a SYN_SENT state.
Using
system.net.tcp.paws_connection_dropas the metric name for PAWSActive made more sense.Number of retransmitted SYN packets: TCPSynRetrans
Number of socket closed due to a TCP timeout (maximum retransmission
reached or keep-alive timeouts): TCPAbortOnTimeout
0win state changes: TCPFromZeroWindowAdv, TCPToZeroWindowAdv
Syn cookies stats: SyncookiesSent, SyncookiesRecv, SyncookiesFailed
Reused TW socket: TWRecycled.
This can easily be confused with the
tcp_tw_recyclesysctl optionwhich doesn't exist anymore.
In the kernel code, we can see it's incremented if the tw reuse was
successful (
twsk_unique(sk, sk2, twp))https://github.com/torvalds/linux/blob/19757cebf0c5016a1f36f7fe9810a9f0b33c0832/net/ipv4/inet_hashtables.c#L487-L490
So I've used
system.net.tcp.tw_reusedfor this one which makes a bitmore sense.
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