systemd-backoff

systemd-backoff is a tool that can be used to add exponential backoff capability to a systemd unit. It expects to be run as part of a systemd unit, and will use sd_pid_get_unit to fetch the current unit name, and then fetches the NRestarts property that describes the number of restarts for the current unit. Once it has this value, it uses that as the input to wait an amount of time configured by the exponential backoff parameters command line arguments.

Arguments

Usage of systemd-backoff:
  -debug
    	print debug messages
  -factor float
    	multiplication factor for each attempt (default 1.5)
  -jitter
    	randomize backoff steps
  -max duration
    	maximum backoff duration (default 10s)
  -min duration
    	minimum backoff duration (default 100ms)

There are two environment variables that can be set for debugging:

  • SYSTEMD_BACKOFF_UNIT_NAME, if set to a string, specifies the current unit name (and does not detect it at runtime).
  • SYSTEMD_BACKOFF_DEBUG_RESTARTS, if set to an integer, fakes the number of restarts (NRestarts) to the provided number.

Example Usage

In a systemd unit file; using the + sigil to run the backoff script as root so it can communicate with systemd.

ExecStartPre=+/usr/local/bin/systemd-backoff -max 30s -factor 1.5

GitHub

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