Downtimed

Christian Külker

0.1.1

2024-03-11

Introduction

downtimed is a software tool designed for monitoring and recording operating system downtime, uptime, shutdowns, and crashes.

The downtimed daemon initiates at system startup, logging information about the operating system’s last downtime to a log destination and a database. This data is accessible using the downtimes command.

Once initialized, downtimed operates in the background, periodically updating a time-stamp file on the disk. This time-stamp helps estimate the last active period of the system. During a proper system shutdown, downtimed records a separate time-stamp. These records are utilized for reporting in subsequent daemon starts.

downtimes is a command-line interface for reviewing downtime history stored in the database.

The software is compatible with GNU/Linux, FreeBSD, NetBSD, OpenBSD, Mac OS X, and Solaris operating systems and can be adapted for other UNIX-like systems. downtimed is distributed under the Simplified BSD license.

Installation

To install downtimed, use the following command:

aptitude install downtimed

This command installs the following components:

  • Documentation (changelogs, README files)
  • System service configuration for systemd and init.d
  • Database storage location
  • Executable and man page

The following files are part of the package:

/usr/share/doc/downtimed/changelog.gz
/lib/systemd/system/downtimed.service
/etc/init.d/downtimed
/etc/default/downtimed
/usr/share/doc/downtimed/README.Debian
/usr/share/doc/downtimed/README.md.gz
/var/lib/downtimed
/usr/sbin/downtimed
/usr/share/doc/downtimed/copyright
/usr/share/man/man8/downtimed.8.gz
/usr/share/doc/downtimed/changelog.Debian.gz
/usr/share/doc/downtimed/TODO
/usr/share/doc/downtimed

To check the status of the downtimed service, use:

systemctl status downtimed.service
● downtimed.service - Downtime record keeper
     Loaded: loaded (/lib/systemd/system/downtimed.service; enabled; preset: \
             enabled)
     Active: active (running) since Mon 2024-03-11 12:40:45 CET; 3min 24s ago
    Process: 12849 ExecStart=/usr/sbin/downtimed $DOWNTIMED_OPTS \
             (code=exited, status=0/SUCCESS)
   Main PID: 12850 (downtimed)
      Tasks: 1 (limit: 9402)
     Memory: 192.0K
        CPU: 4ms
     CGroup: /system.slice/downtimed.service
             └─12850 /usr/sbin/downtimed

Usage

Initially, if the system has not experienced downtime, attempts to query downtime records using downtime or downtimes will result in error messages indicating the absence of the downtime database file.

downtime
downtime: can not open /var/lib/downtimed/downtimedb: No such file or directory

downtimes
downtimes: can not open /var/lib/downtimed/downtimedb: No such file or directory

After a reboot 31s of downtime can be seen.

downtime
down  2024-03-11 13:05:01 -> up 2024-03-11 13:05:32 =    00:00:31 (31 s)

Both commands have equal output. However after a second reboot downtime and downtimes differ.

downtime
down  2024-03-11 13:07:41 -> up 2024-03-11 13:08:11 =    00:00:30 (30 s)

downtimes
down  2024-03-11 13:05:01 -> up 2024-03-11 13:05:32 =    00:00:31 (31 s)
down  2024-03-11 13:07:41 -> up 2024-03-11 13:08:11 =    00:00:30 (30 s)

History

Version Date Notes
0.1.1 2024-03-11 Release to GitHub, add usage section
0.1.0 2021-02-16 Initial release
  • Downtimed