title: Why lsof report a higher open files number than ulimit's "open file" output
body: <p>Tomcat runs on my workstation for several days, now it has no response, lsof command outputs lots of close_wait state connections, tomcat pid is 25422, however the ulimit command shows that the "open file" is 1024, how can this happen?</p>
  
  <pre><code>[root@localhost home]# lsof -p 25422 | wc -l
  10309
  
  [root@localhost home]# ulimit -a
  core file size          (blocks, -c) 0
  data seg size           (kbytes, -d) unlimited
  scheduling priority             (-e) 0
  file size               (blocks, -f) unlimited
  pending signals                 (-i) 399360
  max locked memory       (kbytes, -l) 32
  max memory size         (kbytes, -m) unlimited
  open files                      (-n) 1024
  pipe size            (512 bytes, -p) 8
  POSIX message queues     (bytes, -q) 819200
  real-time priority              (-r) 0
  stack size              (kbytes, -s) 10240
  cpu time               (seconds, -t) unlimited
  max user processes              (-u) 399360
  virtual memory          (kbytes, -v) unlimited
  file locks                      (-x) unlimited
  </code></pre>