我已经netstat -s在运行 Debian 的专用服务器上执行了。我想解释结果，因为我遇到了 TCP 连接问题。我不知道如何读取这些结果。有人能帮忙吗？
背景：这是一个公共 tcp 服务器，客户端来自世界各地，大多数使用 3G/UMTS 网络。套接字平均打开 1 小时。有些 tcp 链接每 10 分钟左右会停滞 10-60 秒。我正在运行一个自定义 java 程序，即 tcp 服务器。
以下是 的输出netstat -s。它是否显示出任何明显的连接问题？
Ip:
33780786 total packets received
0 forwarded
0 incoming packets discarded
33780059 incoming packets delivered
33577363 requests sent out
1 outgoing packets dropped
1442 reassemblies required
715 packets reassembled ok
Icmp:
4675 ICMP messages received
98 input ICMP message failed.
ICMP input histogram:
destination unreachable: 2901
timeout in transit: 152
echo requests: 1334
echo replies: 226
2109 ICMP messages sent
0 ICMP messages failed
ICMP output histogram:
destination unreachable: 550
echo request: 225
echo replies: 1334
IcmpMsg:
InType0: 226
InType3: 2901
InType8: 1334
InType11: 152
OutType0: 1334
OutType3: 550
OutType8: 225
Tcp:
8752 active connections openings
287296 passive connection openings
58164 failed connection attempts
74065 connection resets received
30 connections established
32997886 segments received
32357425 segments send out
438184 segments retransmited
587 bad segments received.
75868 resets sent
Udp:
777245 packets received
550 packets to unknown port received.
0 packet receive errors
779944 packets sent
TcpExt:
28674 invalid SYN cookies received
56570 resets received for embryonic SYN_RECV sockets
998 packets pruned from receive queue because of socket buffer overrun
9 ICMP packets dropped because they were out-of-window
27402 packets rejects in established connections because of timestamp
1266543 delayed acks sent
1399 delayed acks further delayed because of locked socket
Quick ack mode was activated 143367 times
1556 times the listen queue of a socket overflowed
1556 SYNs to LISTEN sockets dropped
25884635 packets directly queued to recvmsg prequeue.
785180902 bytes directly in process context from backlog
1800599695 bytes directly received in process context from prequeue
2879633 packet headers predicted
7627605 packets header predicted and directly queued to user
3218508 acknowledgments not containing data payload received
14774120 predicted acknowledgments
52 times recovered from packet loss due to fast retransmit
24519 times recovered from packet loss by selective acknowledgements
4 bad SACK blocks received
Detected reordering 146 times using FACK
Detected reordering 77 times using SACK
Detected reordering 2239 times using time stamp
3548 congestion windows fully recovered without slow start
15840 congestion windows partially recovered using Hoe heuristic
8832 congestion windows recovered without slow start by DSACK
127403 congestion windows recovered without slow start after partial ack
12080 TCP data loss events
TCPLostRetransmit: 3
179 timeouts after reno fast retransmit
21328 timeouts after SACK recovery
1481 timeouts in loss state
32373 fast retransmits
5349 forward retransmits
26402 retransmits in slow start
230593 other TCP timeouts
4 classic Reno fast retransmits failed
2367 SACK retransmits failed
563 times receiver scheduled too late for direct processing
243774 packets collapsed in receive queue due to low socket buffer
151068 DSACKs sent for old packets
45306 DSACKs sent for out of order packets
238987 DSACKs received
14 DSACKs for out of order packets received
27627 connections reset due to unexpected data
4045 connections reset due to early user close
4992 connections aborted due to timeout
IpExt:
答案1
1 outgoing packets dropped
几乎没有数据包丢失，这很好，但我们没有延迟数据。乍一看，我会说你使用的工具不对。
是否涉及数据库？是否存在某种循环功能，导致系统在 10 分钟左右变慢？该机器是否仅运行此 tcp 服务器，还是正在为其他资源提供服务？
Netstat 并不是一个适合你做事的指标。为了确保你的 Web 应用程序按预期运行，你需要一个具有以下特征的基础设施
答案2
以下这些内容可以帮助您理解该问题：
- 您的接收程序如何处理来自网络连接？它是多线程的吗？它如何处理客户端？是否达到超时？
- 您如何测试服务器代码？您是否在本地机器上运行过它并测试过可以建立多少个连接？您是否测试过长会话的效果？
- 尝试运行“netstat -p”或“lsof -i TCP”，看看发生了什么。发送队列是什么样子的？运行“ps auxwww”，服务器程序的状态是什么？