Daemon Service/Process

  • concept in operating system
  • runs in the background on a computer system.
  • typically started at boot time and runs until the system is shut down.
  • often used to provide system-level functionality, such as:
    • logging
    • networking
    • printing

Daemon Threads

  • concept in java/python
  • low priority thread that keeps running in background
  • once the main thread exits and all non-daemon threads are also done, program exits and all the daemon threads will be killed
  • Since they abruptly terminate, you should never use them with I/O tasks which can corrupt data
  • some examples:
    • garbage collection
    • sending keepalive packets