Documentation
Table of Contents
3 Agent 2
Overview
Zabbix agent 2 is a new generation of Zabbix agent and may be used in place of Zabbix agent. Zabbix agent 2 has been developed to:
- reduce the number of TCP connections
- have greater check concurrency
- be easily extendible with plugins. A plugin should be able to:
- provide trivial checks consisting of only a few simple lines of code
- provide complex checks consisting of long-running scripts and standalone data gathering with periodic sending back of the data
- be a drop-in replacement for Zabbix agent (in that it supports all the previous functionality)
Agent 2 is written in Go (with some C code of Zabbix agent reused). A configured Go environment with a currently supported Go version is required for building Zabbix agent 2.
Agent 2 does not have built-in daemonization support on Linux; it can be run as a Windows service.
Passive checks work similarly to Zabbix agent. Active checks support scheduled/flexible intervals and check concurrency within one active server.
** Check concurrency **
Checks from different plugins can be executed concurrently. The number of concurrent checks within one plugin is limited by the plugin capacity setting. Each plugin may have a hardcoded capacity setting (100 being default) that can be lowered using the Plugins.<Plugin name>.Capacity=N setting in the Plugins configuration parameter.
See also: Plugin development guidelines.
Supported platforms
Agent 2 is supported for Linux and Windows platforms.
If installing from packages, Agent 2 is supported on:
- RHEL/CentOS 6, 7, 8
- SLES 15 SP1+
- Debian 9, 10
- Ubuntu 18.04, 20.04
On Windows Agent 2 is supported on:
- Windows Server 2008 R2 and later
- Windows 7 and later
Installation
Zabbix agent 2 is available in pre-compiled Zabbix packages. To compile Zabbix agent 2 from sources you have to specify the --enable-agent2 configure option.
Options
The following command line parameters can be used with Zabbix agent 2:
| Parameter | Description |
|---|---|
| -c --config <config-file> | Path to the configuration file. You may use this option to specify a configuration file that is not the default one. On UNIX, default is /usr/local/etc/zabbix_agent2.conf or as set by compile-time variables --sysconfdir or --prefix |
| -f --foreground | Run Zabbix agent in foreground (default: true). |
| -p --print | Print known items and exit. Note: To return user parameter results as well, you must specify the configuration file (if it is not in the default location). |
| -t --test <item key> | Test specified item and exit. Note: To return user parameter results as well, you must specify the configuration file (if it is not in the default location). |
| -h --help | Print help information and exit. |
| -v --verbose | Print debugging information. Use this option with -p and -t options. |
| -V --version | Print agent version number and exit. |
| -R --runtime-control <option> | Perform administrative functions. See runtime control. |
Specific examples of using command line parameters:
- print all built-in agent items with values
- test a user parameter with "mysql.ping" key defined in the specified configuration file
Runtime control
Runtime control provides some options for remote control.
| Option | Description |
|---|---|
| log_level_increase | Increase log level. |
| log_level_decrease | Decrease log level. |
| metrics | List available metrics. |
| version | Display agent version. |
| help | Display help information on runtime control. |
Examples:
- increasing log level for agent 2
- print runtime control options
Configuration file
The configuration parameters of agent 2 are mostly compatible with Zabbix agent with some exceptions.
| New parameters | Description |
|---|---|
| ControlSocket | The runtime control socket path. Agent 2 uses a control socket for runtime commands. |
| EnablePersistentBuffer, PersistentBufferFile, PersistentBufferPeriod |
These parameters are used to configure persistent storage on agent 2 for active items. |
| Plugins | Plugins may have their own parameters, in the format Plugins.<Plugin name>.<Parameter>=<value>. A common plugin parameter is Capacity, setting the limit of checks that can be executed at the same time. |
| StatusPort | The port agent 2 will be listening on for HTTP status request and display of a list of configured plugins and some internal parameters |
| Dropped parameters | Description |
| AllowRoot, User | Not supported because daemonization is not supported. |
| LoadModule, LoadModulePath | Loadable modules are not supported. |
| StartAgents | This parameter was used in Zabbix agent to increase passive check concurrency or disable them. In Agent 2, the concurrency is configured at a plugin level and can be limited by a capacity setting. Whereas disabling passive checks is not currently supported. |
| HostInterface, HostInterfaceItem | Not yet supported. |
For more details see the configuration file options for zabbix_agent2.
Exit codes
Starting from version 4.4.8 Zabbix agent 2 can also be compiled with older OpenSSL versions (1.0.1, 1.0.2).
In this case Zabbix provides mutexes for locking in OpenSSL. If a mutex lock or unlock fails then an error message is printed to the standard error stream (STDERR) and Agent 2 exits with return code 2 or 3, respectively.