System Monitoring in UNIX.adoc

System Monitoring in UNIX

Table of Contents

• Sample Apache configuration for Netdata

Tool	Debian Packages	Written in	Stars	Storage	SNMP	NRPE	Prometheus	Web Server	Comments
MRTG	standard	Perl	218	RRDTool	Yes			External (Apache)
Cacti	standard	PHP	1.5k	RRDTool, MySQL	Yes			External (Apache)	Debian package can automatically integrate with apache2 or lighttpd (the installer automatically creates /etc/apache2/conf-available/cacti.conf). At the same time, Cacti can’t proceed w/o a MySQL database, and database connection needs to be configured manually, via /usr/share/cacti/site/include/config.php (the dbconfig-mysql package generates /etc/cacti/debian.php and creates a symlink, but the file needs to be revised afterwards). The default administrator (admin) password is the same as the database password.
Monitorix	standard	Perl	1.1k	RRDTool	No	No	No	Built-in (monitorix-httpd listening on port 8080)	Simple to set up and run. Few dependencies. Plenty of metrics available by default.
Icinga	standard or external	C++	1.9k		Yes	Yes
Zabbix	standard or external	C, Go, PHP (front-end)	3.4k	MySQL or PostgreSQL (via ODBC)	Yes		Yes	External (Apache, Nginx, or any other)	Can use either MySQL or PostgreSQL as a storage layer. Can monitor JVM applications via JMX. Standard Debian packages have been removed from testing. The agent listens at TCP port 10050 (either zabbix-agent (for SysV init) or zabbix-agent2 (for systemd) package should be used, but not both). The standard Debian package has outdated Apache configuration: it contains php_value definitions for either mod_php5.c or mod_php7.c, while the current PHP version in Debian 12 is 8.2, and we need either <IfModule mod_php.c> or <IfModule php_module>. The database needs to be manually created by running SQL scripts (schema.sql, then images.sql followed by data.sql). The database collation should be set to either of utf8_bin, utf8mb3_bin, or utf8mb4_bin. Also, when using MariaDB (the default MySQL choice on Debian), AllowUnsupportedDBVersions should be set to 1. The default username is Admin with the password zabbix.
Prometheus	standard	Go	50.3k		Yes		Yes	Built-in	By default, listens at TCP port 9090, which may conflict with a TeamCity Agent or a MinIO container, if both are running on the same host. Can monitor S.M.A.R.T attributes out of the box, using the prometheus-node-exporter-collectors package.
OpenNMS	external	Java	844	JRobin or RRDTool (via jrrd2) or Newts, PostgreSQL (versions 10 to 15).	Yes	Yes	Yes	Built-in (Jetty), on port 8980	Painless installation. Administration Guide. Can receive data from Nagios NRPE agents.
Sensu Go	external	Go, previously Ruby	922	PostgreSQL				Built-in, on port 3000	No initscripts, no config file templates (intended to run in a Docker container). The default PostgreSQL config file location in Debian 12 is /etc/postgresql/15/main/pg_hba.conf.
Netdata	standard (1.37.1) or external (1.43.0)	C	65.5k	Only real-time data by default, but multiple export destinations may be configured.	Yes (requires netdata-plugin-go)		Yes	External (Apache) or built-in	Plug-ins can be written in Bash or Python.
Grafana	external (version 9.5 can also be installed from OpenNMS repository)	TypeScript, Go	57.6k
Elasticsearch	external	Java	65.5k
openITCOCKPIT	external	PHP	229	RRDTool, Redis		Yes	Yes	External (Nginx)	Conflicts with Apache. Automatically installs Grafana. Pulls and starts images of Puppeteer and Nodejs.
Pandora FMS	standard (agent only) and external (server)	PHP	404	MySQL					Dozens of dependencies, installation script intended only for Ubuntu Linux and can only be run as root.

Sample Apache configuration for Netdata

<IfModule mod_proxy.c>
        ProxyRequests Off
        ProxyPreserveHost On

        ProxyPass /netdata http://127.0.0.1:19999 connectiontimeout=5 timeout=30 keepalive=on
        ProxyPassReverse /netdata http://127.0.0.1:19999
</IfModule>

<IfModule mod_rewrite.c>
        RewriteEngine On
        RewriteRule ^/netdata$ /netdata/ [L,R=301]
</IfModule>