From: Simon Ruderich <simon@ruderich.org>
Date: Sun, 18 Aug 2013 14:27:13 +0000 (+0200)
Subject: crontab.d/jobs: Random sleep before running a command.
X-Git-Url: https://ruderich.org/simon/gitweb/?a=commitdiff_plain;h=556fcce13fb08df53b84f2878fdff27464aacf6b;p=config%2Fdotfiles.git

crontab.d/jobs: Random sleep before running a command.
---

diff --git a/crontab.d/jobs b/crontab.d/jobs
index fb83d9a..8f575fc 100644
--- a/crontab.d/jobs
+++ b/crontab.d/jobs
@@ -21,15 +21,18 @@
 # Include user's binaries in PATH. Expanding $HOME doesn't work with cron,
 # `update.sh` handles that!
 PATH=$HOME/bin:$HOME/.shell/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
+# "RAND_SLEEP X" is also expanded by `update.sh` to a command which sleeps
+# randomly between 0 and X seconds. Used to reduce concurrent commands if this
+# crontab file is used by multiple users.
 
 
 # Taken from Debian's /etc/crontab from cron package 3.0pl1-124 and modified.
 # Thanks.
-17 * * * * run-parts --report .crontab.d/jobs.hourly
-25 6 * * * run-parts --report .crontab.d/jobs.daily
-47 6 * * 7 run-parts --report .crontab.d/jobs.weekly
-52 6 1 * * run-parts --report .crontab.d/jobs.monthly
+17 * * * * RAND_SLEEP 60;   run-parts --report .crontab.d/jobs.hourly
+25 6 * * * RAND_SLEEP 1800; run-parts --report .crontab.d/jobs.daily
+47 6 * * 7 RAND_SLEEP 3600; run-parts --report .crontab.d/jobs.weekly
+52 6 1 * * RAND_SLEEP 3600; run-parts --report .crontab.d/jobs.monthly
 
 # Run every x hours.
-31 */6 * * * run-parts --report .crontab.d/jobs.hourly6
-39 */8 * * * run-parts --report .crontab.d/jobs.hourly8
+31 */6 * * * RAND_SLEEP 600; run-parts --report .crontab.d/jobs.hourly6
+39 */8 * * * RAND_SLEEP 600; run-parts --report .crontab.d/jobs.hourly8
diff --git a/crontab.d/update.sh b/crontab.d/update.sh
index 062c34e..173142e 100755
--- a/crontab.d/update.sh
+++ b/crontab.d/update.sh
@@ -78,6 +78,7 @@ for file in "$DIRECTORY"/crontab.*; do
                   -e "/^# Copyright (C) [0-9][0-9]* / d" \
         | cat --squeeze-blank \
         | sed "/^PATH/ s:\$HOME:$HOME:g" \
+        | sed 's/RAND_SLEEP \([0-9]*\)/sleep `perl -e "srand; print int rand \1;"`/' \
         >> "$CRONTAB"
 done