3 Agent 2

Overview

Zabbix agent 2 is a new generation of Zabbix agent, written in Go (with some C code reused from Zabbix agent). It is designed to:

  • Reduce the number of TCP connections.
  • Provide improved concurrency of checks.
  • Be easily extendable with plugins, which provide simple checks with minimal code and support complex checks consisting of long-running scripts and standalone data gathering with periodic reporting.
  • Function as a replacement for Zabbix agent, supporting all previous features.
Passive and active checks

Zabbix agent 2 supports passive and active checks, similarly to Zabbix agent. Additionally, Zabbix agent 2 active checks support flexible/scheduling intervals and check concurrency within one active server.

By default, after a restart, Zabbix agent 2 will schedule the first data collection for active checks at a conditionally random time within the item's update interval to prevent spikes in resource usage. To perform active checks that do not have Scheduling update interval immediately after the agent restart, set ForceActiveChecksOnStart parameter (global-level) or Plugins.<Plugin name>.System.ForceActiveChecksOnStart (affects only specific plugin checks) in the configuration file. Plugin-level parameter, if set, will override the global parameter.

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 (1000 being default) that can be lowered using the Plugins.<PluginName>.System.Capacity=N setting in the Plugins configuration parameter.

Supported platforms

For supported platforms, refer to the Requirements page.

Agent 2 on UNIX-like systems

Zabbix agent 2 on UNIX-like systems is run on the host being monitored.

Installation

Zabbix agent 2 can be installed on Linux-based systems using one of the following methods:

  • Zabbix packages - select the Agent 2 component (after selecting your Zabbix version, OS distribution, and OS version) and follow the instructions.
  • Zabbix sources - download the source files and compile the agent by configuring with the --enable-agent2 option.

The monitoring capabilities of Zabbix agent 2 can be extended with loadable plugins, which are available separately. For details, see Loadable plugins.

If installed as package

Zabbix agent 2 runs as a foreground process and relies on an external service manager (e.g., systemd) for background execution; Zabbix agent 2 does not have built-in daemonization support on Linux.

The agent can be started by executing:

systemctl start zabbix-agent2

To stop, restart, or check the status of Zabbix agent 2, use the following commands:

systemctl stop zabbix-agent2
systemctl restart zabbix-agent2
systemctl status zabbix-agent2
Start up manually

You can start Zabbix agent by locating the zabbix_agent2 binary and running it directly; for example:

zabbix_agent2

Agent 2 on Windows systems

Zabbix agent 2 runs as a standalone process; however, it can also be run as a Windows service.

Installation

Zabbix agent 2 can be installed on Windows using one of the following methods:

The monitoring capabilities of Zabbix agent 2 can be extended with loadable plugins, which are available separately. For details, see Loadable plugins.

See the Zabbix agent on Microsoft Windows page for additional details on installing Zabbix agent 2 (from a ZIP archive) as a Windows service.

Options

The following command-line parameters can be used with Zabbix agent 2:

Parameter Description
UNIX and Windows agent
-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
On Windows, default is C:\Program Files\Zabbix Agent 2\zabbix_agent2.conf
-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).
-T --test-config Validate configuration file and exit.
-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 and license information.
-R --runtime-control <option> Perform administrative functions. See runtime control.
Windows agent only
-m --multiple-agents Use multiple agent instances (with -i, -d, -s, -x options).
To distinguish service names of instances, each service name will include the Hostname value from the specified configuration file.
-S --startup-type <value> Set the startup type of the Zabbix Windows agent service. Allowed values:
automatic - (default) start the service automatically at Windows startup;
delayed - delay starting the service after the automatically started services have completed startup;
manual - start the service manually (by a user or application);
disabled - disable the service, so that it cannot be started by a user or application.
You may use this option together with the -i option, or separately to modify the startup type of an already installed service.
-i --install Install Zabbix Windows agent as service.
-d --uninstall Uninstall Zabbix Windows agent service.
-s --start Start Zabbix Windows agent service.
-x --stop Stop Zabbix Windows agent service.

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
  • installing a "Zabbix Agent" service for Windows using the default path to configuration file C:\Program Files\Zabbix Agent 2\zabbix_agent2.conf
  • modifying the startup type of an installed "Zabbix Agent" service for Windows using the configuration file zabbix_agent2.conf located in the same folder as agent executable
zabbix_agent2 --print
zabbix_agent2 -t "mysql.ping" -c /etc/zabbix/zabbix_agentd.conf
zabbix_agent2.exe -i
zabbix_agent2.exe -c zabbix_agent2.conf -S delayed
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.
userparameter_reload Reload values of the UserParameter and Include options from the current configuration file.
help Display help information on runtime control.

Examples:

  • increasing log level for agent 2
  • print runtime control options
zabbix_agent2 -R log_level_increase
zabbix_agent2 -R help

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.
ForceActiveChecksOnStart Determines whether the agent should perform active checks immediately after restart or spread evenly over time.
Plugins Plugins may have their own parameters, in the format Plugins.<Plugin name>.<Parameter>=<value>. A common plugin parameter is System.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.

For more details see the configuration file options for zabbix_agent2.

Exit codes

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.