Add TCPOFOQueue to default netstat metrics (#2867)

Adds a count for TCP packets received out of orders. This can be an
indication that there is packet loss on the way packets travel towards
this server. In that case, the sender will retransmit (and we can
already monitor the Tcp_RetransSegs there), but we have no way to
monitor the packet loss on the receiver side. When a packet is received
and the receiver detects previous one missing, it will increase the
TCPOFOQueue counter and reply with selective ACK to the sender, both
possible indications of packet loss. Confirmation of packet loss can be
achieved by taking packet captures, ignoring wireshark analysis, and
carefully looking at data being retransmitted based on the TCP seq.

Just like RetransSegs, TCPOFOQueue should be interesting for any
deployment as a mean to detect packet loss, so here suggesting adding it
to the default list.

Signed-off-by: François Rigault <frigo@amadeus.com>
Co-authored-by: François Rigault <frigo@amadeus.com>
This commit is contained in:
frigo 2023-12-08 18:24:07 +01:00 committed by GitHub
parent 9666d00248
commit 0550ab3f04
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 9 additions and 3 deletions

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@ -2303,6 +2303,9 @@ node_netstat_TcpExt_SyncookiesRecv 0
# HELP node_netstat_TcpExt_SyncookiesSent Statistic TcpExtSyncookiesSent.
# TYPE node_netstat_TcpExt_SyncookiesSent untyped
node_netstat_TcpExt_SyncookiesSent 0
# HELP node_netstat_TcpExt_TCPOFOQueue Statistic TcpExtTCPOFOQueue.
# TYPE node_netstat_TcpExt_TCPOFOQueue untyped
node_netstat_TcpExt_TCPOFOQueue 42
# HELP node_netstat_TcpExt_TCPTimeouts Statistic TcpExtTCPTimeouts.
# TYPE node_netstat_TcpExt_TCPTimeouts untyped
node_netstat_TcpExt_TCPTimeouts 115

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@ -2325,6 +2325,9 @@ node_netstat_TcpExt_SyncookiesRecv 0
# HELP node_netstat_TcpExt_SyncookiesSent Statistic TcpExtSyncookiesSent.
# TYPE node_netstat_TcpExt_SyncookiesSent untyped
node_netstat_TcpExt_SyncookiesSent 0
# HELP node_netstat_TcpExt_TCPOFOQueue Statistic TcpExtTCPOFOQueue.
# TYPE node_netstat_TcpExt_TCPOFOQueue untyped
node_netstat_TcpExt_TCPOFOQueue 42
# HELP node_netstat_TcpExt_TCPTimeouts Statistic TcpExtTCPTimeouts.
# TYPE node_netstat_TcpExt_TCPTimeouts untyped
node_netstat_TcpExt_TCPTimeouts 115

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@ -1,4 +1,4 @@
TcpExt: SyncookiesSent SyncookiesRecv SyncookiesFailed EmbryonicRsts PruneCalled RcvPruned OfoPruned OutOfWindowIcmps LockDroppedIcmps ArpFilter TW TWRecycled TWKilled PAWSPassive PAWSActive PAWSEstab DelayedACKs DelayedACKLocked DelayedACKLost ListenOverflows ListenDrops TCPPrequeued TCPDirectCopyFromBacklog TCPDirectCopyFromPrequeue TCPPrequeueDropped TCPHPHits TCPHPHitsToUser TCPPureAcks TCPHPAcks TCPRenoRecovery TCPSackRecovery TCPSACKReneging TCPFACKReorder TCPSACKReorder TCPRenoReorder TCPTSReorder TCPFullUndo TCPPartialUndo TCPDSACKUndo TCPLossUndo TCPLoss TCPLostRetransmit TCPRenoFailures TCPSackFailures TCPLossFailures TCPFastRetrans TCPForwardRetrans TCPSlowStartRetrans TCPTimeouts TCPRenoRecoveryFail TCPSackRecoveryFail TCPSchedulerFailed TCPRcvCollapsed TCPDSACKOldSent TCPDSACKOfoSent TCPDSACKRecv TCPDSACKOfoRecv TCPAbortOnData TCPAbortOnClose TCPAbortOnMemory TCPAbortOnTimeout TCPAbortOnLinger TCPAbortFailed TCPMemoryPressures TCPSACKDiscard TCPDSACKIgnoredOld TCPDSACKIgnoredNoUndo TCPSpuriousRTOs TCPMD5NotFound TCPMD5Unexpected TCPSackShifted TCPSackMerged TCPSackShiftFallback TCPBacklogDrop TCPMinTTLDrop TCPDeferAcceptDrop IPReversePathFilter TCPTimeWaitOverflow TCPReqQFullDoCookies TCPReqQFullDrop TCPChallengeACK TCPSYNChallenge
TcpExt: 0 0 2 0 0 0 0 0 0 0 388812 0 0 0 0 6 102471 17 9 0 0 80568 0 168808 0 4471289 26 1433940 3744565 0 1 0 0 0 0 0 0 0 0 48 0 0 0 1 0 1 0 1 115 0 0 0 0 9 0 5 0 41 4 0 0 0 0 0 0 0 1 0 0 0 0 2 5 0 0 0 0 0 0 0 2 2
TcpExt: SyncookiesSent SyncookiesRecv SyncookiesFailed EmbryonicRsts PruneCalled RcvPruned OfoPruned OutOfWindowIcmps LockDroppedIcmps ArpFilter TW TWRecycled TWKilled PAWSPassive PAWSActive PAWSEstab DelayedACKs DelayedACKLocked DelayedACKLost ListenOverflows ListenDrops TCPPrequeued TCPDirectCopyFromBacklog TCPDirectCopyFromPrequeue TCPPrequeueDropped TCPHPHits TCPHPHitsToUser TCPPureAcks TCPHPAcks TCPRenoRecovery TCPSackRecovery TCPSACKReneging TCPFACKReorder TCPSACKReorder TCPRenoReorder TCPTSReorder TCPFullUndo TCPPartialUndo TCPDSACKUndo TCPLossUndo TCPLoss TCPLostRetransmit TCPRenoFailures TCPSackFailures TCPLossFailures TCPFastRetrans TCPForwardRetrans TCPSlowStartRetrans TCPTimeouts TCPRenoRecoveryFail TCPSackRecoveryFail TCPSchedulerFailed TCPRcvCollapsed TCPDSACKOldSent TCPDSACKOfoSent TCPDSACKRecv TCPDSACKOfoRecv TCPAbortOnData TCPAbortOnClose TCPAbortOnMemory TCPAbortOnTimeout TCPAbortOnLinger TCPAbortFailed TCPMemoryPressures TCPSACKDiscard TCPDSACKIgnoredOld TCPDSACKIgnoredNoUndo TCPSpuriousRTOs TCPMD5NotFound TCPMD5Unexpected TCPSackShifted TCPSackMerged TCPSackShiftFallback TCPBacklogDrop TCPMinTTLDrop TCPDeferAcceptDrop IPReversePathFilter TCPTimeWaitOverflow TCPReqQFullDoCookies TCPReqQFullDrop TCPChallengeACK TCPSYNChallenge TCPOFOQueue
TcpExt: 0 0 2 0 0 0 0 0 0 0 388812 0 0 0 0 6 102471 17 9 0 0 80568 0 168808 0 4471289 26 1433940 3744565 0 1 0 0 0 0 0 0 0 0 48 0 0 0 1 0 1 0 1 115 0 0 0 0 9 0 5 0 41 4 0 0 0 0 0 0 0 1 0 0 0 0 2 5 0 0 0 0 0 0 0 2 2 42
IpExt: InNoRoutes InTruncatedPkts InMcastPkts OutMcastPkts InBcastPkts OutBcastPkts InOctets OutOctets InMcastOctets OutMcastOctets InBcastOctets OutBcastOctets
IpExt: 0 0 0 0 0 0 6286396970 2786264347 0 0 0 0

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@ -36,7 +36,7 @@ const (
)
var (
netStatFields = kingpin.Flag("collector.netstat.fields", "Regexp of fields to return for netstat collector.").Default("^(.*_(InErrors|InErrs)|Ip_Forwarding|Ip(6|Ext)_(InOctets|OutOctets)|Icmp6?_(InMsgs|OutMsgs)|TcpExt_(Listen.*|Syncookies.*|TCPSynRetrans|TCPTimeouts)|Tcp_(ActiveOpens|InSegs|OutSegs|OutRsts|PassiveOpens|RetransSegs|CurrEstab)|Udp6?_(InDatagrams|OutDatagrams|NoPorts|RcvbufErrors|SndbufErrors))$").String()
netStatFields = kingpin.Flag("collector.netstat.fields", "Regexp of fields to return for netstat collector.").Default("^(.*_(InErrors|InErrs)|Ip_Forwarding|Ip(6|Ext)_(InOctets|OutOctets)|Icmp6?_(InMsgs|OutMsgs)|TcpExt_(Listen.*|Syncookies.*|TCPSynRetrans|TCPTimeouts|TCPOFOQueue)|Tcp_(ActiveOpens|InSegs|OutSegs|OutRsts|PassiveOpens|RetransSegs|CurrEstab)|Udp6?_(InDatagrams|OutDatagrams|NoPorts|RcvbufErrors|SndbufErrors))$").String()
)
type netStatCollector struct {