From fca20a1be69d0ffe3067e5c8676d75b5f8af1a5d Mon Sep 17 00:00:00 2001 From: Adrian Vovk Date: Tue, 18 Feb 2025 15:59:03 -0500 Subject: [PATCH] man/systemd.timer: Correct inaccuracy in man page The docs previously stated that RandomizedDelaySec is applied onto the next scheduled time, but after 9fa326b18aef0c1e5c80e23a5b41de02155e6f7e this is no longer the case. I also reworded FixedRandomDelay= slightly, to make it a bit clearer --- man/systemd.timer.xml | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/man/systemd.timer.xml b/man/systemd.timer.xml index f2035a541f4..8a81d5066db 100644 --- a/man/systemd.timer.xml +++ b/man/systemd.timer.xml @@ -266,9 +266,9 @@ Delay the timer by a randomly selected, evenly distributed amount of time between 0 and the specified time value. Defaults to 0, indicating that no randomized delay shall be applied. - Each timer unit will determine this delay randomly before each iteration, and the delay will simply - be added on top of the next determined elapsing time, unless modified with - FixedRandomDelay=, see below. + Each timer unit will determine this delay randomly before each iteration, unless modified with + FixedRandomDelay=, see below. The delay is added on top of the next determined + elapsing time or the service manager's startup time, whichever is later. This setting is useful to stretch dispatching of similarly configured timer events over a certain time interval, to prevent them from firing all at the same time, possibly resulting in @@ -292,12 +292,12 @@ FixedRandomDelay= - Takes a boolean argument. When enabled, the randomized offset specified by - RandomizedDelaySec= is reused for all firings of the same timer. For a given timer - unit, the offset depends on the machine ID, user identifier and timer name, which means that it is - stable between restarts of the manager. This effectively creates a fixed offset for an individual - timer, reducing the jitter in firings of this timer, while still avoiding firing at the same time as - other similarly configured timers. + Takes a boolean argument. When enabled, the randomized delay specified by + RandomizedDelaySec= is chosen deterministically, and remains stable between all + firings of the same timer, even if the manager is restarted. The delay is derived from the machine + ID, the manager's user identifier, and the timer unit's name. This effectively creates a unique fixed + offset for each timer, reducing the jitter in firings of an individual timer while still avoiding + firing at the same time as other similarly configured timers. This setting has no effect if RandomizedDelaySec= is set to 0. Defaults to . -- 2.47.3