concurrency notes

gistfile1.md

Count All Open File Handles

lsof | wc -l

List File Descriptors in Kernel Memory

sysctl fs.file-nr

• Sample outputs:

fs.file-nr = 1020	0	70000

• Where,
  • 1020 The number of allocated file handles.
  • 0 The number of unused-but-allocated file handles.
  • 70000 The system-wide maximum number of file handles.

Logrotate Example:

• Create /etc/logrotate.d/foo-app-logs file with following snippet:

  /var/log/foo-app/*.log {
          daily
          size 500M
          missingok
          rotate 10
          compress
          delaycompress
          notifempty
          create 664 deploy devops
  }
  

• Activate it as:

  sudo logrotate -f /etc/logrotate.d/foo-app-logs
  

• Cross Verify here:

  less /var/lib/logrotate/status | grep foo-app-logs
  

Links:

• http://stackoverflow.com/questions/14763079/what-are-the-xms-and-xmx-parameters-when-starting-jvms
• https://rtcamp.com/tutorials/linux/increase-open-files-limit/
• http://stackoverflow.com/questions/21515463/how-to-increase-maximum-file-open-limit-ulimit-in-ubuntu
• www.http-kit.org/600k-concurrent-connection-http-kit.html