Есть сервер как фронт, он проксирует трафик при помощи nginx на бекенды, канал загружен примерно на 150 мегабит при гигабитном канале.
Не могу понять что случилось, но сервер перестал принимать входящие запросы именно на на 80 порт, если nginx поставить на два 80 и 81 порт, 81 запросы нормально проходят без задержек, а на 80 не проходят...вернее проходят, но как то через раз а то и через 10 раз.
12:05:50.681946 IP y.y.y.y.50486 > x.x.x.x.80: Flags [S], seq 1836049420, win 14600, options [mss 1460,nop,nop,TS val 730771892 ecr 0], length 0
0x0000: 90e6 baca 2b9f 00d0 015e 2c00 0800 4500 ....+....^,...E.
0x0010: 0038 55b8 4000 3906 8d3f 4e2e 3104 d917 .8U.@.9..?N.1...
0x0020: 067f c536 0050 6d6f e40c 0000 0000 9002 ...6.Pmo........
0x0030: 3908 d2f8 0000 0204 05b4 0101 080a 2b8e 9.............+.
0x0040: b1b4 0000 0000 ......
и все завис,
а на 81 порт проходит нормально все
12:05:39.158898 IP y.y.y.y.36886 > x.x.x.x.81: Flags [S], seq 1570498657, win 14600, options [mss 1460,nop,nop,TS val 730769011 ecr 0], length 0
0x0000: 90e6 baca 2b9f 00d0 015e 2c00 0800 4500 ....+....^,...E.
0x0010: 0038 4e12 4000 3906 94e5 4e2e 3104 d917 .8N.@.9...N.1...
0x0020: 067f 9016 0051 5d9b e861 0000 0000 9002 .....Q]..a......
0x0030: 3908 1ed8 0000 0204 05b4 0101 080a 2b8e 9.............+.
0x0040: a673 0000 0000 .s....
12:05:39.158906 IP x.x.x.x.81 > y.y.y.y.36886: Flags [S.], seq 3794583370, ack 1570498658, win 5792, options [mss 1460,nop,nop,TS val 4294964954 ecr 730769011], length 0
0x0000: 00d0 015e 2c00 90e6 baca 2b9f 0800 4500 ...^,.....+...E.
0x0010: 0038 0000 4000 4006 dbf7 d917 067f 4e2e .8..@.@.......N.
0x0020: 3104 0051 9016 e22c bf4a 5d9b e862 9012 1..Q...,.J]..b..
0x0030: 16a0 a8dc 0000 0204 05b4 0101 080a ffff ................
0x0040: f6da 2b8e a673 ..+..s
sysctl весь по-умолчанию debian , кроме этого
fs.file-max = 80000
net.core.netdev_max_backlog = 30000
#net.core.somaxconn = 562144
net.core.somaxconn = 1024
net.ipv4.conf.all.accept_redirects=0
net.ipv4.conf.all.accept_source_route=0
net.ipv4.conf.all.forwarding=1
net.ipv4.conf.all.log_martians=1
net.ipv4.conf.all.rp_filter=1
net.ipv4.conf.all.send_redirects=0
net.ipv4.icmp_echo_ignore_broadcasts=1
net.ipv4.icmp_ignore_bogus_error_responses=1
net.ipv4.ip_forward = 1
net.ipv4.ipfrag_low_thresh = 262144
net.ipv4.ipfrag_time = 30
net.ipv4.tcp_abort_on_overflow = 0
net.ipv4.tcp_ecn = 1
net.ipv4.tcp_fin_timeout=60
net.ipv4.tcp_keepalive_intvl=30
net.ipv4.tcp_keepalive_probes=3
net.ipv4.tcp_keepalive_time=7200
net.ipv4.tcp_max_orphans = 262144
net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.tcp_max_tw_buckets = 7200000
net.ipv4.tcp_mem = 19232 200229760 850344640
net.ipv4.tcp_orphan_retries = 6
#net.ipv4.tcp_rmem = 4096 87380 4194304
net.ipv4.tcp_sack = 1
net.ipv4.tcp_synack_retries = 5
net.ipv4.tcp_syncookies=0
net.ipv4.tcp_syn_retries=3
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_window_scaling=1
net.ipv4.tcp_wmem = 4096 16384 131070
net.netfilter.nf_conntrack_max=100485760
net.core.wmem_default = 4194394
net.core.rmem_default = 8388608
net.core.wmem_max = 33554432
net.core.rmem_max = 33554432
в netstat много ошибок очень
Tcp:
24330 active connections openings
130217 passive connection openings
11662 failed connection attempts
1617 connection resets received
6182 connections established
12975448 segments received
983226 segments send out
27921 segments retransmited
82 bad segments received.
43139 resets sent
UdpLite:
TcpExt:
11659 resets received for embryonic SYN_RECV sockets
27517 TCP sockets finished time wait in fast timer
185 packets rejects in established connections because of timestamp
599 delayed acks sent
1 delayed acks further delayed because of locked socket
Quick ack mode was activated 3010 times
1 packets directly queued to recvmsg prequeue.
154183 packet headers predicted
488360 acknowledgments not containing data payload received
9755 predicted acknowledgments
8 times recovered from packet loss by selective acknowledgements
1 bad SACK blocks received
5 congestion windows recovered without slow start by DSACK
4264 congestion windows recovered without slow start after partial ack
8 TCP data loss events
TCPLostRetransmit: 1
1 timeouts after reno fast retransmit
133 timeouts after SACK recovery
3 timeouts in loss state
23 fast retransmits
2 forward retransmits
35 retransmits in slow start
13829 other TCP timeouts
2 SACK retransmits failed
2722 DSACKs sent for old packets
1 DSACKs sent for out of order packets
7884 DSACKs received
31 connections reset due to unexpected data
2148 connections aborted due to timeout
TCPDSACKIgnoredOld: 2991
TCPDSACKIgnoredNoUndo: 2735
TCPSpuriousRTOs: 6
TCPSackShiftFallback: 265
dmesg не чего полезного нет