3 Zabbix agent (UNIX)

Overview

This section lists parameters supported in a Zabbix agent configuration file (zabbix_agentd.conf). Note that:

  • The default values reflect daemon defaults, not the values in the shipped configuration files;
  • Zabbix supports configuration files only in UTF-8 encoding without BOM;
  • Comments starting with “#” are only supported in the beginning of the line.

Parameters

ParameterMandatoryRangeDefaultDescription
AliasnoSets an alias for an item key. It can be used to substitute long and complex item key with a smaller and simpler one.
Multiple Alias parameters may be present. Multiple parameters with the same Alias key are allowed.
Different Alias keys may reference the same item key.
Aliases can be used in HostMetadataItem but not in HostnameItem parameters.

Examples:

1. Retrieving the ID of user ‘zabbix’.
Alias=zabbix.userid:vfs.file.regexp[/etc/passwd,”^zabbix:.:([0-9]+)”,,,,\1]
Now shorthand key zabbix.userid may be used to retrieve data.

2. Getting CPU utilization with default and custom parameters.
Alias=cpu.util:system.cpu.util
Alias=cpu.util[]:system.cpu.util[]
This allows use cpu.util key to get CPU utilization percentage with default parameters as well as use cpu.util[all, idle, avg15] to get specific data about CPU utilization.

3. Running multiple low-level discovery rules processing the same discovery items.
Alias=vfs.fs.discovery[]:vfs.fs.discovery
Now it is possible to set up several discovery rules using vfs.fs.discovery with different parameters for each rule, e.g., vfs.fs.discovery[foo], vfs.fs.discovery[bar], etc.
AllowKeynoAllow execution of those item keys that match a pattern. Key pattern is a wildcard expression that supports ““ character to match any number of any characters.
Multiple key matching rules may be defined in combination with DenyKey. The parameters are processed one by one according to their appearance order.
This parameter is supported since Zabbix 5.0.0.
See also: Restricting agent checks.
AllowRootno0Allow the agent to run as ‘root’. If disabled and the agent is started by ‘root’, the agent will try to switch to user ‘zabbix’ instead. Has no effect if started under a regular user.
0 - do not allow
1 - allow
BufferSendno1-36005Do not keep data longer than N seconds in buffer.
BufferSizeno2-65535100Maximum number of values in a memory buffer. The agent will send
all collected data to Zabbix server or proxy if the buffer is full.
DebugLevelno0-53Specifies debug level:
0 - basic information about starting and stopping of Zabbix processes
1 - critical information
2 - error information
3 - warnings
4 - for debugging (produces lots of information)
5 - extended debugging (produces even more information)
DenyKeynoDeny execution of those item keys that match a pattern. Key pattern is a wildcard expression that supports ““ character to match any number of any characters.
Multiple key matching rules may be defined in combination with AllowKey. The parameters are processed one by one according to their appearance order.
This parameter is supported since Zabbix 5.0.0.
See also: Restricting agent checks.
EnableRemoteCommandsno0Whether remote commands from Zabbix server are allowed. This parameter is deprecated, use AllowKey=system.run[] or DenyKey=system.run[] instead
It is internal alias for AllowKey/DenyKey parameters depending on value: 0 - DenyKey=system.run[]
1 - AllowKey=system.run[]
HostInterfaceno0-255 charactersOptional parameter that defines host interface.
Host interface is used at host autoregistration process.
An agent will issue an error and not start if the value is over the limit of 255 characters.
If not defined, value will be acquired from HostInterfaceItem.
Supported since Zabbix 4.4.0.
HostInterfaceItemnoOptional parameter that defines an item used for getting host interface.
Host interface is used at host autoregistration process.
During an autoregistration request an agent will log a warning message if the value returned by specified item is over limit of 255 characters.
This option is only used when HostInterface is not defined.
Supported since Zabbix 4.4.0.
HostMetadatano0-255 charactersOptional parameter that defines host metadata. Host metadata is used only at host autoregistration process (active agent).
If not defined, the value will be acquired from HostMetadataItem.
An agent will issue an error and not start if the specified value is over the limit or a non-UTF-8 string.
HostMetadataItemnoOptional parameter that defines a Zabbix agent item used for getting host metadata. This option is only used when HostMetadata is not defined.
Supports UserParameters and aliases. Supports system.run[] regardless of AllowKey/DenyKey values.
HostMetadataItem value is retrieved on each autoregistration attempt and is used only at host autoregistration process (active agent).
During an autoregistration request an agent will log a warning message if the value returned by the specified item is over the limit of 255 characters.
The value returned by the item must be a UTF-8 string otherwise it will be ignored.
HostnamenoSet by HostnameItemList of comma-delimited unique, case-sensitive hostnames.
Required for active checks and must match hostnames as configured on the server. Value is acquired from HostnameItem if undefined.
Allowed characters: alphanumeric, ‘.’, ‘ ‘, ‘_’ and ‘-‘.
Maximum length: 128 characters per hostname, 2048 characters for the entire line.
HostnameItemnosystem.hostnameOptional parameter that defines a Zabbix agent item used for getting host name. This option is only used when Hostname is not defined.
Does not support UserParameters or aliases, but does support system.run[] regardless of AllowKey/DenyKey values.
The output length is limited to 512KB.
IncludenoYou may include individual files or all files in a directory in the configuration file.
To only include relevant files in the specified directory, the asterisk wildcard character is supported for pattern matching. For example: /absolute/path/to/config/files/.conf.
See special notes about limitations.
ListenBacklogno0 - INT_MAXSOMAXCONNThe maximum number of pending connections in the TCP queue.
Default value is a hard-coded constant, which depends on the system.
Maximum supported value depends on the system, too high values may be silently truncated to the ‘implementation-specified maximum’.
ListenIPno0.0.0.0List of comma delimited IP addresses that the agent should listen on.
Multiple IP addresses are supported in version 1.8.3 and higher.
ListenPortno1024-3276710050Agent will listen on this port for connections from the server.
LoadModulenoModule to load at agent startup. Modules are used to extend functionality of the agent.
Formats:
LoadModule=<module.so>
LoadModule=<path/module.so>
LoadModule=</abs_path/module.so>
Either the module must be located in directory specified by LoadModulePath or the path must precede the module name. If the preceding path is absolute (starts with ‘/‘) then LoadModulePath is ignored.
It is allowed to include multiple LoadModule parameters.
LoadModulePathnoFull path to location of agent modules.
Default depends on compilation options.
LogFileyes, if LogType is set to file, otherwise
no		Name of log file.
LogFileSizeno0-10241Maximum size of log file in MB.
0 - disable automatic log rotation.
Note: If the log file size limit is reached and file rotation fails, for whatever reason, the existing log file is truncated and started anew.
LogTypenofileLog output type:
file - write log to file specified by LogFile parameter,
system - write log to syslog,
console - write log to standard output.
This parameter is supported since Zabbix 3.0.0.
LogRemoteCommandsno0Enable logging of executed shell commands as warnings.
0 - disabled
1 - enabled
Commands will be logged only if executed remotely. Log entries will not be created if system.run[] is launched locally by HostMetadataItem, HostInterfaceItem or HostnameItem parameters.
MaxLinesPerSecondno1-100020Maximum number of new lines the agent will send per second to Zabbix server or proxy when processing ‘log’ and ‘eventlog’ active checks.
The provided value will be overridden by the parameter ‘maxlines’,
provided in ‘log’ or ‘eventlog’ item key.
Note: Zabbix will process 10 times more new lines than set in MaxLinesPerSecond to seek the required string in log items.
PidFileno/tmp/zabbix_agentd.pidName of PID file.
RefreshActiveChecksno60-3600120How often list of active checks is refreshed, in seconds.
Note that after failing to refresh active checks the next refresh will be attempted after 60 seconds.
Serveryes, if StartAgents is not explicitly set to 0List of comma delimited IP addresses, optionally in CIDR notation, or hostnames of Zabbix servers and Zabbix proxies.
Incoming connections will be accepted only from the hosts listed here.
If IPv6 support is enabled then ‘127.0.0.1’, ‘::127.0.0.1’, ‘::ffff:127.0.0.1’ are treated equally and ‘::/0’ will allow any IPv4 or IPv6 address.
‘0.0.0.0/0’ can be used to allow any IPv4 address.
Note, that “IPv4-compatible IPv6 addresses” (0000::/96 prefix) are supported but deprecated by RFC4291.
Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.domain
Spaces are allowed.
ServerActivenoList of comma-delimited IP address or DNS name (address:port) pairs or clusters (address:port;address2:port) of Zabbix servers and Zabbix proxies for active checks.
Cluster nodes must be separated by a semicolon.
Multiple comma-delimited addresses can be provided to use several independent Zabbix servers in parallel. Spaces are allowed.
If port is not specified, default port is used.
IPv6 addresses must be enclosed in square brackets if port for that host is specified.
If port is not specified, square brackets for IPv6 addresses are optional.
If this parameter is not specified, active checks are disabled.
Example for multiple servers:
ServerActive=127.0.0.1:20051,zabbix.domain,[::1]:30051,::1,[12fc::1]
Example for high availability:
ServerActive=zabbix.cluster.node1;zabbix.cluster.node2:20051;zabbix.cluster.node3
Example for high availability with two clusters and one server:
ServerActive=zabbix.cluster.node1;zabbix.cluster.node2:20051,zabbix.cluster2.node1;zabbix.cluster2.node2,zabbix.domain
SourceIPnoSource IP address for:
- outgoing connections to Zabbix server or Zabbix proxy;
- making connections while executing some items (web.page.get, net.tcp.port, etc.)
StartAgentsno0-1003Number of pre-forked instances of zabbix_agentd that process passive checks.
If set to 0, disables passive checks and the agent will not listen on any TCP port.
Timeoutno1-303Spend no more than Timeout seconds on processing.
TLSAcceptyes, if TLS certificate or PSK parameters are defined (even for unencrypted connection), otherwise noWhat incoming connections to accept. Used for a passive checks. Multiple values can be specified, separated by comma:
unencrypted - accept connections without encryption (default)
psk - accept connections with TLS and a pre-shared key (PSK)
cert - accept connections with TLS and a certificate
This parameter is supported since Zabbix 3.0.0.
TLSCAFilenoFull pathname of a file containing the top-level CA(s) certificates for peer certificate verification, used for encrypted communications between Zabbix components.
This parameter is supported since Zabbix 3.0.0.
TLSCertFilenoFull pathname of a file containing the agent certificate or certificate chain, used for encrypted communications with Zabbix components.
This parameter is supported since Zabbix 3.0.0.
TLSCipherAllnoGnuTLS priority string or OpenSSL (TLS 1.2) cipher string. Override the default ciphersuite selection criteria for certificate- and PSK-based encryption.
Example: TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256
This parameter is supported since Zabbix 4.4.7.
TLSCipherAll13noCipher string for OpenSSL 1.1.1 or newer in TLS 1.3. Override the default ciphersuite selection criteria for certificate- and PSK-based encryption.
Example for GnuTLS: NONE:+VERS-TLS1.2:+ECDHE-RSA:+RSA:+ECDHE-PSK:+PSK:+AES-128-GCM:+AES-128-CBC:+AEAD:+SHA256:+SHA1:+CURVE-ALL:+COMP-NULL::+SIGN-ALL:+CTYPE-X.509
Example for OpenSSL: EECDH+aRSA+AES128:RSA+aRSA+AES128:kECDHEPSK+AES128:kPSK+AES128
This parameter is supported since Zabbix 4.4.7.
TLSCipherCertnoGnuTLS priority string or OpenSSL (TLS 1.2) cipher string. Override the default ciphersuite selection criteria for certificate-based encryption.
Example for GnuTLS: NONE:+VERS-TLS1.2:+ECDHE-RSA:+RSA:+AES-128-GCM:+AES-128-CBC:+AEAD:+SHA256:+SHA1:+CURVE-ALL:+COMP-NULL:+SIGN-ALL:+CTYPE-X.509
Example for OpenSSL: EECDH+aRSA+AES128:RSA+aRSA+AES128
This parameter is supported since Zabbix 4.4.7.
TLSCipherCert13noCipher string for OpenSSL 1.1.1 or newer in TLS 1.3. Override the default ciphersuite selection criteria for certificate-based encryption.
This parameter is supported since Zabbix 4.4.7.
TLSCipherPSKnoGnuTLS priority string or OpenSSL (TLS 1.2) cipher string. Override the default ciphersuite selection criteria for PSK-based encryption.
Example for GnuTLS: NONE:+VERS-TLS1.2:+ECDHE-PSK:+PSK:+AES-128-GCM:+AES-128-CBC:+AEAD:+SHA256:+SHA1:+CURVE-ALL:+COMP-NULL:+SIGN-ALL
Example for OpenSSL: kECDHEPSK+AES128:kPSK+AES128
This parameter is supported since Zabbix 4.4.7.
TLSCipherPSK13noCipher string for OpenSSL 1.1.1 or newer in TLS 1.3. Override the default ciphersuite selection criteria for PSK-based encryption.
Example: TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256
This parameter is supported since Zabbix 4.4.7.
TLSConnectyes, if TLS certificate or PSK parameters are defined (even for unencrypted connection), otherwise noHow the agent should connect to Zabbix server or proxy. Used for active checks. Only one value can be specified:
unencrypted - connect without encryption (default)
psk - connect using TLS and a pre-shared key (PSK)
cert - connect using TLS and a certificate
This parameter is supported since Zabbix 3.0.0.
TLSCRLFilenoFull pathname of a file containing revoked certificates. This parameter is used for encrypted communications with Zabbix components.
This parameter is supported since Zabbix 3.0.0.
TLSKeyFilenoFull pathname of a file containing the agent private key used for encrypted communications with Zabbix components.
This parameter is supported since Zabbix 3.0.0.
TLSPSKFilenoFull pathname of a file containing the agent pre-shared key used for encrypted communications with Zabbix components.
This parameter is supported since Zabbix 3.0.0.
TLSPSKIdentitynoPre-shared key identity string, used for encrypted communications with Zabbix server.
This parameter is supported since Zabbix 3.0.0.
TLSServerCertIssuernoAllowed server (proxy) certificate issuer.
This parameter is supported since Zabbix 3.0.0.
TLSServerCertSubjectnoAllowed server (proxy) certificate subject.
This parameter is supported since Zabbix 3.0.0.
UnsafeUserParametersno0,10Allow all characters to be passed in arguments to user-defined parameters.
0 - do not allow
1 - allow
The following characters are not allowed:
\ ‘ “ ` * ? [ ] { } ~ $ ! & ; ( ) < > | # @
Additionally, newline characters are not allowed.
UsernozabbixDrop privileges to a specific, existing user on the system.
Only has effect if run as ‘root’ and AllowRoot is disabled.
UserParameternoUser-defined parameter to monitor. There can be several user-defined parameters.
Format: UserParameter=<key>,<shell command>
Note that shell command must not return empty string or EOL only.
Shell commands may have relative paths, if UserParameterDir parameter is specified.
Examples:
UserParameter=system.test,who|wc -l
UserParameter=check_cpu,./custom_script.sh
UserParameterDirnoDefault search path for UserParameter commands. If used, the agent will change its working directory to the one specified here before executing a command. Thereby, UserParameter commands can have a relative ./ prefix instead of a full path.
Only one entry is allowed.
Example: UserParameterDir=/opt/myscripts

See also

  1. Differences in the Zabbix agent configuration for active and passive checks starting from version 2.0.0