Heartbeat is a Server Farmer subproject, that extends functionally your chosen monitoring/alerting solution by providing abilities to monitor:
- services listening on known ports
- running Docker containers
- running libvirt-based virtual machines
- SMART for local drives (also SAS and all drives connected through hardware RAID controllers)
- free space under critical directories (eg.
/var/lib/mysql- directories are detected automatically, see below)
- mounted LUKS encrypted drives (or just any device mapper based)
- custom conditions defined per monitored host
Heartbeat can work with any monitoring/alerting system, that supports http(s) keyword monitoring, including:
- public: StatusCake, Uptimerobot, Pingdom etc.
- local: Nagios, Icinga, Zabbix, PRTG etc.
This versions is compatible with:
- Linux (all distributions, possibly except some minimal ones)
- FreeBSD 9.x or later
- OpenBSD 5.x or later
- NetBSD 6.x or later
Heartbeat can be installed in 2 modes: with or without Server Farmer.
- With Server Farmer it:
- is installed automatically on all Linux/FreeBSD-based hosts
/etc/heartbeat/hooks/smart.shhook for Cacti and NewRelic (see below)
- uses Heartbeat server address from
/opt/farm/config/get-url-heartbeat.shscript (see below)
- Manual installation without Server Farmer:
git clone https://github.com/serverfarmer/heartbeat-linux /opt/heartbeat /opt/heartbeat/setup.sh
Next, put your Heartbeat instance url into
/etc/heartbeat/server.url file (unless you want to use the public instance, eg. for testing).
OS specific notes
Make sure that
smartmontools packages are installed. Update CA root certificates if needed.
NetBSD, OpenBSD, Slackware
crontab -e as root and add this line to crontab:
*/2 * * * * /opt/heartbeat/scripts/cron/update.sh
NetBSD earlier than 7
Make sure that
smartmontools packages are installed. Installing
smartmontools will require changing
PKG_PATH variable first, to point to release 7 repository, eg.
After installing (and each upgrade of)
mozilla-rootcerts package, execute
mozilla-rootcerts install as root to refresh CA root certificates.
How it works
- Cron job
/opt/heartbeat/scripts/cron/update.shis run every 2 minutes.
- It runs
/opt/heartbeat/scripts/checks/all.shscript to collect detected items to report. This script can be also run manually for debugging purposes - it just prints all found items on console.
- Cron job sends the collected list to Heartbeat server.
Heartbeat server address detection:
- Cron job looks for
/etc/heartbeat/server.urlfile - if it exists, it should contain the full path to Heartbeat server.
- If Server Farmer is also installed, cron job uses server address returned by
/opt/farm/config/get-url-heartbeat.shscript. So if you cloned Server Farmer main repository and changed mentioned script to point to your private instance, it will be automatically detected here.
- Otherwise it uses hardcoded
https://serverfarmer.home.pl/heartbeat/(public Heartbeat instance).
- Your chosen monitoring/alerting platform is querying Heartbeat server for particular item on particular monitored host.
- Heartbeat server responds with either
ALIVEmeans that this item was last reported no longer than 270 seconds ago.
Items are reported every 120 seconds, so 270 seconds means tolerance for 1 failed request + up to 30 seconds overall network lag. And this limit can be easily adjusted in repository with server part.
Query URL format
- your Heartbeat server has address
- your example monitored host has hostname
this is the complete URL that checks for
ssh service running on this host:
- everything is converted to lowercase
- underlines, colons and slashes are replaced with dashes
- dots in hostnames are replaced with underlines
- network service names are listed in
t2.micro instance, storing temporary files on
tmpfs filesystem, can handle over 3000 individual checks without any performance issues, assuming that queries from monitoring system are done via http (no encryption), every 1 minute.
Note that you can use different addresses for reporting data from monitored hosts, and for querying (in particular, you can use https for reporting and http for querying over internal network).
SMART monitoring details
Heartbeat automatically detects all local drives, even ones not supported by udev:
- SATA drives connected straight, or via USB or eSATA (including with port multiplier), or even as passthrough from hypervisor to virtual machine
- SATA/SAS drives connected to MegaRAID controller
- SATA/SAS drives connected to any custom hardware controller, assuming that such drives are exposed via
Server Farmer hook for Cacti and NewRelic
For each detected and not excluded drive (not necessarily meeting conditions described below), Heartbeat executes
/etc/heartbeat/hooks/smart.sh script, with the full name of SMART dump file as the only argument. When Heartbeat is installed by Server Farmer, this file is installed automatically, you can however replace it with your own one.
Version provided by Server Farmer:
- parses the SMART dump again and pushes the drive metrics to NewRelic (assuming that
sf-monitoring-newrelicextension is installed and NewRelic license key is properly configured)
- copies this dump using scp to Cacti server (assuming that
sf-monitoring-cactiextension is installed)
Handling known drive defects
In highly professional use, drives mostly work in stable physical conditions for all their lifetime. This is often not the case for smaller companies or private use, where physical conditions (eg. temperature, cables etc.) can change from time to time.
Because of that, some particular SMART errors can happen and shouldn't be considered a problem. For example, non-zero
UDMA_CRC_Error_Count is often a result of bad eSATA cable/connector, and it stays non-zero even after the cable is replaced. And there are numerous similar exceptions, where certain defects doesn't yet mean that drive should be replaced.
/etc/heartbeat/known-smart-defects.conf you can store such exceptions, eg.:
means that this particular drive is allowed to run with allowed temperature increased by 2 degrees from standard (which is not recommended anyway, but it's a better solution than simply dropping such drive).
Excluding problematic drives
There are certain cases, where you want to exclude particular drives from being detected and checked every 2 minutes, for example:
- unstable RAID controller, causing random system crashes during SMART read attempts
- USB drives in external enclosures, meant to be either disconnected or put in
standbycondition for most of the time, that might overheat otherwise
You can add such drives to these files to exclude them from being detected:
/etc/heartbeat/skip-smart.sata(drives recognized and handled by udev)
/etc/heartbeat/skip-smart.raid(drives connected to hardware RAID controllers)
Required SMART conditions for SATA drives
Temperature_Celsius- max 48 degrees for magnetic drives, or 55 degrees for SSD
Runtime_Bad_Block- max 10
Current_Pending_Sector- max 2
Power_On_Hours- max 70000 (which is around 8 years)
Required SMART conditions for SAS drives
Drive temperature is not monitored, since SAS drives have Drive Trip Temperature mechanism.
Elements in grown defect list(similar to
Reallocated_Sector_Ct) - max 4
Non-medium error count(similar to
UDMA_CRC_Error_Count) - max 10
- ECC-corrected reads - max 6
- ECC-corrected writes - max 2
- ECC-corrected verifications - max 2
number of hours powered up- max 70000 (only for Seagate and Hitachi drives)
Free space monitoring details
/opt/heartbeat/config/common-data-directories.list file contains the list of directories commonly used to storage bigger amounts of data, eg. by databases, queues, (para)virtualization etc. This file is processed during Heartbeat setup and any directories from this list that actually exist on current host, are added to
/etc/heartbeat/detected-data-directories.conf file. Next, they are checked every 2 minutes, if they have at least 12 GB of free disk space.
Additionally, root filesystem is required to have 512 MB of free space, and
/boot directory - 80 MB.
Such limits are designed to give system administrators just enough time to safely deal with the problem - not to assure that system will be able to run for next weeks or months. You can however implement your own limits, just by adding the following line to custom check script:
/opt/heartbeat/scripts/checks/space-check.sh /var/lib 491520000
This example check will require
/var/lib directory to have at least 480 GB of free space, or otherwise it will fail.
Implementing custom checks
You can implement custom checks just by adding them to
/etc/heartbeat/hooks/custom.sh script. It just needs to print the list of passed checks on console, one per line. For example, the above check for
/var/lib directory free space should just print:
It is important that this script, or scripts/libraries/etc. that you invoke from it, should not print anything else on console - otherwise it will be sent to Heartbeat server and might interfere with other checks.
To simplify your custom logic, you can also use
/opt/heartbeat/scripts/checks/custom/count-processes.sh script, that counts the processes with given name pattern, eg.:
/opt/heartbeat/scripts/checks/custom/count-processes.sh app/console 34 my-symfony-app-console
Such script will print
my-symfony-app-console if there will be at least 34 running processes with
app/console in their names. Note that you can use spaces in the first argument
/opt/heartbeat/scripts/checks/custom/count-processes.sh "app/console rabbitmq:consumer" 31 rabbit-consumer
To see, what is reported to Heartbeat server, just run:
/opt/heartbeat/scripts/checks/all.sh- to see the list of reported checks (running it with
--debugargument will disable SMART hook script and removing temporary files with SMART dumps)
/opt/heartbeat/scripts/facts/get-reported-hostname.sh- to see the hostname used for reporting
If you added/removed drives or directories to monitor free space, run
/opt/heartbeat/setup.sh to scan system for changes.
All Heartbeat settings are stored in
/etc/heartbeat directory, and temporary files in
/var/cache/heartbeat (which should be mounted as
/opt/heartbeat/scripts/checks/all.sh script shows many errors, when run manually
Make sure that you have installed all required system packages. See notes above.
/opt/heartbeat/scripts/cron/update.sh script is added to
/etc/crontab, but doesn't run
Add it to root crontab manually using
crontab -e command. See notes above.
/opt/heartbeat/scripts/cron/update.sh script runs, but can't contact Heartbeat server
Make sure that your CA root certificates are up to date (this is the most common problem on old systems).
How to contribute
We are welcome to contributions of any kind: bug fixes, added code comments, support for new operating system versions or hardware etc.
If you want to contribute:
- fork this repository and clone it to your machine
- create a feature branch and do the change inside it
- push your feature branch to github and create a pull request
|Author:||Tomasz Klim (email@example.com)|
|Copyright:||Copyright 2016-2021 Tomasz Klim|
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