mum*_*eka 6 networking tcp linux-networking centos5
我有一个使用 TCP 连接运行的游戏服务器。服务器随机断开用户连接。我认为它与服务器的 TCP 设置有关。
在本地开发环境中编写的代码可以处理 8000+ 并发用户而不会出现任何断开或错误（在 localhost 上）。
但是在实际部署的 Centos 5 64bit Server 中，服务器创建这些断开连接与并发 tcp 连接数量无关。
服务器似乎无法处理吞吐量。
netstat -s -t
IcmpMsg:
InType0: 31
InType3: 87717
InType4: 699
InType5: 2
InType8: 1023781
InType11: 7211
OutType0: 1023781
OutType3: 603
Tcp:
8612766 active connections openings
14255236 passive connection openings
12174 failed connection attempts
319225 connection resets received
723 connections established
6351090913 segments received
6180297746 segments send out
45791634 segments retransmited
0 bad segments received.
1664280 resets sent
TcpExt:
46244 invalid SYN cookies received
3745 resets received for embryonic SYN_RECV sockets
327 ICMP packets dropped because they were out-of-window
1 ICMP packets dropped because socket was locked
11475281 TCP sockets finished time wait in fast timer
140 time wait sockets recycled by time stamp
1569 packets rejects in established connections because of timestamp
103783714 delayed acks sent
6929 delayed acks further delayed because of locked socket
Quick ack mode was activated 6210096 times
1806 times the listen queue of a socket overflowed
1806 SYNs to LISTEN sockets ignored
1080380601 packets directly queued to recvmsg prequeue.
31441059 packets directly received from backlog
5272599307 packets directly received from prequeue
324498008 packets header predicted
1143146 packets header predicted and directly queued to user
3217838883 acknowledgments not containing data received
1027969883 predicted acknowledgments
395 times recovered from packet loss due to fast retransmit
257420 times recovered from packet loss due to SACK data
5843 bad SACKs received
Detected reordering 29 times using FACK
Detected reordering 12 times using SACK
Detected reordering 1 times using reno fast retransmit
Detected reordering 809 times using time stamp
1602 congestion windows fully recovered
1917 congestion windows partially recovered using Hoe heuristic
TCPDSACKUndo: 8196226
7850525 congestion windows recovered after partial ack
139681 TCP data loss events
TCPLostRetransmit: 26
10139 timeouts after reno fast retransmit
2802678 timeouts after SACK recovery
86212 timeouts in loss state
273698 fast retransmits
19494 forward retransmits
2637236 retransmits in slow start
33381883 other TCP timeouts
TCPRenoRecoveryFail: 92
19488 sack retransmits failed
7 times receiver scheduled too late for direct processing
6354641 DSACKs sent for old packets
333 DSACKs sent for out of order packets
20615579 DSACKs received
2724 DSACKs for out of order packets received
123034 connections reset due to unexpected data
91876 connections reset due to early user close
169244 connections aborted due to timeout
28736 times unabled to send RST due to no memory
IpExt:
InMcastPkts: 2
让我思考的是这些似乎很有问题。
123034 connections reset due to unexpected data
91876 connections reset due to early user close
28736 times unabled to send RST due to no memory
我该如何修复这些错误？我需要进行 TCP 调优吗？
编辑：一些 sysctl 信息：
sysctl -A | grep net | grep mem
net.ipv4.udp_wmem_min = 4096
net.ipv4.udp_rmem_min = 4096
net.ipv4.udp_mem = 772704 1030272 1545408
net.ipv4.tcp_rmem = 4096 87380 4194304
net.ipv4.tcp_wmem = 4096 16384 4194304
net.ipv4.tcp_mem = 196608 262144 393216
net.ipv4.igmp_max_memberships = 20
net.core.optmem_max = 20480
net.core.rmem_default = 129024
net.core.wmem_default = 129024
net.core.rmem_max = 131071
net.core.wmem_max = 131071
编辑： 2 个检测到的以太网卡的 ethtool 信息：
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: g
Wake-on: d
Link detected: yes
Settings for eth1:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: Unknown!
Duplex: Half
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: g
Wake-on: d
Link detected: no