Zabbix Documentation 3.0

2.23.04.0 (current)In development:4.2 (devel)Unsupported:1.82.02.43.23.4

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manual:config:items:item

1 Creating an item

Overview

To create an item in Zabbix frontend, do the following:

  • Go to: ConfigurationHosts
  • Click on Items in the row of the host
  • Click on Create item in the upper right corner of the screen
  • Enter parameters of the item in the form

Configuration

Item attributes:

ParameterDescription
Name This is how the item will be named.
The following macros can be used:
$1, $2…$9 - referring to the first, second… ninth parameter of the item key
For example: Free disk space on $1
If the item key is “vfs.fs.size[/,free]”, the description will automatically change to “Free disk space on /”
Type Item type. See individual item type sections.
Key Item key.
The supported item keys can be found in individual item type sections.
The key must be unique within a single host.
If key type is 'Zabbix agent', 'Zabbix agent (active)', 'Simple check' or 'Zabbix aggregate', the key value must be supported by Zabbix agent or Zabbix server.
See also: the correct key format.
Host interface Select the host interface. This field is available when editing an item on the host level.
Type of information Type of data as stored in the database after performing conversions, if any.
Numeric (unsigned) - 64bit unsigned integer
Numeric (float) - floating point number
Negative values can be stored.
Allowed range: -999999999999.9999 to 999999999999.9999.
Starting with Zabbix 2.2, receiving values in scientific notation is also supported. E.g. 1e+7, 1e-4.
Character - short text data
Log - long text data with optional log related properties (timestamp, source, severity, logeventid)
Text - long text data
Limits of text data are described in the table below.
Data type Data type is used for integer items in order to specify the expected data type:
Boolean - textual representation translated into either 0 or 1. Thus, 'TRUE' is stored as 1 and 'FALSE' is stored as 0. All values are matched in a case-insensitive way. Currently recognized values are, for:
TRUE - true, t, yes, y, on, up, running, enabled, available
FALSE - false, f, no, n, off, down, unused, disabled, unavailable
Additionally, any non-zero numeric value is considered to be TRUE and zero is considered to be FALSE.
Octal - data in octal format
Decimal - data in decimal format
Hexadecimal - data in hexadecimal format
Zabbix will automatically perform the conversion to numeric.
The conversion is done by Zabbix server (even when a host is monitored by Zabbix proxy).
Units If a unit symbol is set, Zabbix will add post processing to the received value and display it with the set unit postfix.
By default, if the raw value exceeds 1000, it is divided by 1000 and displayed accordingly. For example, if you set bps and receive a value of 881764, it will be displayed as 881.76 Kbps.
Special processing is used for B (byte), Bps (bytes per second) units, which are divided by 1024. Thus, if units are set to B or Bps Zabbix will display:
1 as 1B/1Bps
1024 as 1KB/1KBps
1536 as 1.5KB/1.5KBps
Special processing is used if the following time-related units are used:
unixtime - translated to “yyyy.mm.dd hh:mm:ss”. To translate correctly, the received value must be a Numeric (unsigned) type of information.
uptime - translated to “hh:mm:ss” or “N days, hh:mm:ss”
For example, if you receive the value as 881764 (seconds), it will be displayed as “10 days, 04:56:04”
s - translated to “yyy mmm ddd hhh mmm sss ms”; parameter is treated as number of seconds.
For example, if you receive the value as 881764 (seconds), it will be displayed as “10d 4h 56m”
Only 3 upper major units are shown, like “1m 15d 5h” or “2h 4m 46s”. If there are no days to display, only two levels are displayed - “1m 5h” (no minutes, seconds or milliseconds are shown). Will be translated to “< 1 ms” if the value is less than 0.001.
See also the unit blacklist.
Use custom multiplier If you enable this option, all received values will be multiplied by the integer or floating-point value set in the value field.
Use this option to convert values received in KB, MBps, etc into B, Bps. Otherwise Zabbix cannot correctly set prefixes (K, M, G etc).
Starting with Zabbix 2.2, using scientific notation is also supported. E.g. 1e+70.
Update interval (in sec) Retrieve a new value for this item every N seconds. Maximum allowed update interval is 86400 seconds (1 day).
Note: If set to '0', the item will not be polled. However, if a custom interval (flexible/scheduling) also exists with a non-zero value, the item will be polled during the custom interval duration.
Custom intervals You can create custom rules for checking the item:
Flexible - create an exception to the Update interval (interval with different frequency)
Scheduling - create a custom polling schedule.
For detailed information see Custom intervals. Scheduling is supported since Zabix 3.0.0.
Note: Not available for Zabbix agent active items.
History storage period
(in days)
Number of days to keep detailed history in the database. Older data will be removed by the housekeeper.
Starting with Zabbix 2.2, this value can be overridden globally in Administration → General → Housekeeper. If the global setting exists, a warning message is displayed:

It is recommended to keep the recorded values for the smallest possible number of days to reduce the size of value history in the database. Instead of keeping long history of values, you can keep longer data of trends.
See also History and trends.
Trend storage period
(in days)
Keep aggregated (hourly min, max, avg, count) detailed history for N days in the database. Older data will be removed by the housekeeper.
Starting with Zabbix 2.2, this value can be overridden globally in Administration → General → Housekeeper. If the global setting exists, a warning message is displayed:

Note: Keeping trends is not available for non-numeric data - character, log and text.
See also History and trends.
Store value As is - no pre-processing
Delta (speed per second) - evaluate value as (value-prev_value)/(time-prev_time), where
value - current value
value_prev - previously received value
time - current timestamp
prev_time - timestamp of previous value
This setting is extremely useful to get speed per second for a constantly growing value.
If current value is smaller than the previous value, Zabbix discards that difference (stores nothing) and waits for another value. This helps to work correctly with, for instance, a wrapping (overflow) of 32-bit SNMP counters.
Note: As this calculation may produce floating point numbers, it is recommended to set the 'Type of information' to Numeric (float), even if the incoming raw values are integers. This is especially relevant for small numbers where the decimal part matters. If the floating point values are large and may exceed the 'float' field length in which case the entire value may be lost, it is actually suggested to use Numeric (unsigned) and thus trim only the decimal part.
Delta (simple change) - evaluate as (value-prev_value), where
value - current value
value_prev - previously received value
This setting can be useful to measure a constantly growing value. If the current value is smaller than the previous value, Zabbix discards that difference (stores nothing) and waits for another value.
Show value Apply value mapping to this item. Value mapping does not change received values, it is for displaying data only.
It works with integer items only.
For example, “Windows service states”.
Log time format Available for items of type Log only. Supported placeholders:
* y: Year (1970-2038)
* M: Month (01-12)
* d: Day (01-31)
* h: Hour (00-23)
* m: Minute (00-59)
* s: Second (00-59)
If left blank the timestamp will not be parsed.
For example, consider the following line from the Zabbix agent log file:
“ 23480:20100328:154718.045 Zabbix agent started. Zabbix 1.8.2 (revision 11211).”
It begins with six character positions for PID, followed by date, time, and the rest of the line.
Log time format for this line would be “pppppp:yyyyMMdd:hhmmss”.
Note that “p” and “:” chars are just placeholders and can be anything but “yMdhms”.
New application Enter the name of a new application for the item.
Applications Link item to one or more existing applications.
Populates host inventory field You can select a host inventory field that the value of item will populate. This will work if automatic inventory population is enabled for the host.
Description Enter an item description.
Enabled Mark the checkbox to enable the item so it will be processed.

You can also create an item by opening an existing one, pressing the Clone button and then saving under a different name.

When editing an existing template level item on a host level, a number of fields are read-only. You can use the link in the form header and go to the template level and edit them there, keeping in mind that the changes on a template level will change the item for all hosts that the template is linked to.

If you use a custom multiplier or store value as Delta (speed per second) for items with the type of information set to Numeric (unsigned) and the resulting calculated value is actually a float number, the calculated value is still accepted as a correct one by trimming the decimal part and storing the value as integer.

Text data limits

Text data limits depend on the database backend. Before storing text values in the database they get truncated to match the database value type limit:

Database Type of information
Character Log Text
MySQL 255 characters 65536 bytes 65536 bytes
PostgreSQL 255 characters 65536 characters 65536 characters
Oracle 255 characters 65536 characters 65536 characters
IBM DB2 255 bytes 2048 bytes 2048 bytes

Unit blacklist

By default, specifying a unit for an item will result in a multiplier prefix being added - for example, value 2048 with unit B would be displayed as 2KB. For a pre-defined, hardcoded list of units this is prevented:

  • ms
  • RPM
  • rpm
  • %

Note that both lowercase and uppercase rpm (rpm and RPM) strings are blacklisted.

Unsupported items

An item can become unsupported if its value cannot be retrieved for some reason. Such items are still rechecked at a fixed interval, configurable in Administration section.

Unsupported items are reported as having a NOT SUPPORTED state.