系統監控

apachetop

監控 apache 伺服器的整體性能。基於 mytop。它會顯示當前的讀取進程、寫入進程的數量以及請求進程的總數。

ftptop

提供了當前所有連接到 ftp 伺服器的基本信息，如會話總數，正在上傳和下載的客戶端數量以及客戶端是誰。

mytop

監控 mysql 的線程和性能。它能讓你實時查看資料庫以及正在處理哪些查詢。

powertop

診斷與電量消耗和電源管理相關的問題

iotop

檢查 I/O 的使用情況，它按列顯示讀和寫的速率，每行代表一個進程。發生交換或 I/O 等待時，它會顯示進程消耗時間的百分比

vnstat

   rx:         0 bit/s     0 p/s          tx:         0 bit/s     0 p/s^C


 wlp4s0  /  traffic statistics

                           rx         |       tx
--------------------------------------+------------------
  bytes                     1.32 KiB  |        2.52 KiB
--------------------------------------+------------------
          max            2.78 kbit/s  |     5.60 kbit/s
      average              773 bit/s  |     1.47 kbit/s
          min                0 bit/s  |         0 bit/s
--------------------------------------+------------------
  packets                         16  |              16
--------------------------------------+------------------
          max                  4 p/s  |           4 p/s
      average                  1 p/s  |           1 p/s
          min                  0 p/s  |           0 p/s
--------------------------------------+------------------
  time                    14 seconds

絡流量監控工具，它的數據統計是由內核進行提供的，其消耗的系統資源非常少

ss

ss是iproute2的一部分， 命令能夠顯示的信息比 netstat 更多，也更快。如果你想查看統計結果的總信息，可以使用命令ss -s

ss -tn -o state established -p

查詢系統上所有使用 IPv4 所開啟的 sockets，並列出每個 sockets 所對應的應用程式：

sudo ss -t4lp
sudo ss -t4lpn

篩選器

列出從本機連線到 192.168.43.100 這台主機的所有連線：

ss -o state established dst 192.168.43.100
Netid               Recv-Q               Send-Q                              Local Address:Port                               Peer Address:Port               
tcp                 0                    0                                  192.168.43.129:ssh                              192.168.43.100:53954               timer:(keepalive,116min,0)

ss -o state established src 192.168.43.100

ss 指令可以自己指定port，篩選出自己需要的 sockets 資訊

ss -o state established '( dport = :ssh or sport = :ssh )'
Netid         Recv-Q         Send-Q                    Local Address:Port                       Peer Address:Port         Process                             
tcp           0              0                         192.168.122.1:38216                   192.168.122.247:ssh           timer:(keepalive,119min,0)         
tcp           0              0                        192.168.43.100:53954                    192.168.43.129:ssh           timer:(keepalive,110min,0)       

ss -o state syn-recv
Netid  Recv-Q Send-Q                                  Local Address:Port                                                   Peer Address:Port                
tcp    0      0                                 2001:288:7201:2::88:http                          2402:7500:466:2f24:84b0:efb4:da74:3ab:51668                 timer:(on,1.660ms,0)
tcp    0      0                                 ::ffff:120.115.2.88:http                                          ::ffff:46.229.168.134:54402                 timer:(on,848ms,0)
tcp    0      0                                 ::ffff:120.115.2.88:http                                          ::ffff:46.229.168.137:45508                 timer:(on,952ms,0)
tcp    0      0                                 2001:288:7201:2::88:http                                          2402:7500:567:5d8f::1:48538                 timer:(on,1.084ms,0)
tcp    0      0                                 2001:288:7201:2::88:http                                          2402:7500:567:5d8f::1:48546                 timer:(on,140ms,0)
tcp    0      0                                 2001:288:7201:2::88:http                                          2402:7500:567:5d8f::1:48539                 timer:(on,1.084ms,0)
tcp    0      0                                 2001:288:7201:2::88:http                            2001:288:759e:0:e8a0:1494:3694:c61b:49182                 timer:(on,4.304ms,0)
tcp    0      0                                 2001:288:7201:2::88:http                         2001:b400:e752:7989:160:a722:fb0d:f54f:46894                 timer:(on,4.620ms,0)
tcp    0      0                                 2001:288:7201:2::88:http                             2001:288:75d6:0:c0f:1b34:9fca:e79c:50063                 timer:(on,372ms,0)
tcp    0      0                                 2001:288:7201:2::88:http                          2402:7500:466:2f24:84b0:efb4:da74:3ab:51667