1 Creating an item

Overview

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

• Go to: Configuration → Hosts
• 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

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

Configuration

The Item tab contains general item attributes.

All mandatory input fields are marked with a red asterisk.

Parameter	Description
Name	Item name. Note that the use of positional macros ($1,$2... $9 - referring to the first, second... ninth parameter of the item key) is now deprecated. 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 (up to 256 characters). 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. See also text data limits.
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. Note that if a unit is prefixed with !, then no unit prefixes/processing is applied to item values. See unit blacklisting.
Update interval	Retrieve a new value for this item every N seconds. Maximum allowed update interval is 86400 seconds (1 day). Time suffixes are supported, e.g. 30s, 1m, 2h, 1d. User macros are supported. A single macro has to fill the whole field. Multiple macros in a field or macros mixed with text are not supported. Note: The update interval can only be set to '0' if custom intervals exist with a non-zero value. If set to '0', and a custom interval (flexible or scheduled) exists with a non-zero value, the item will be polled during the custom interval duration. Note that the first item poll after the item became active or after update interval change might occur earlier than the configured value. An existing passive item can be polled for value immediately by pushing the Check now button.
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. Time suffixes are supported in the Interval field, e.g. 30s, 1m, 2h, 1d. User macros are supported. A single macro has to fill the whole field. Multiple macros in a field or macros mixed with text are not supported. Scheduling is supported since Zabbix 3.0.0. Note: Not available for Zabbix agent active items.
History storage period	Select either: Do not keep history - item history is not stored. Useful for master items if only dependent items need to keep history. This setting cannot be overridden by global housekeeper settings. Storage period - specify the duration of keeping detailed history in the database (1 hour to 25 years). Older data will be removed by the housekeeper. Stored in seconds. Time suffixes are supported, e.g. 2h, 1d. User macros are supported. The Storage period value can be overridden globally in Administration → General → Housekeeper. If a global overriding setting exists, a green info icon is displayed. If you position your mouse on it, a warning message is displayed, e. g. Overridden by global housekeeper settings (1d). It is recommended to keep the recorded values for the smallest possible time to reduce the size of value history in the database. Instead of keeping a long history of values, you can keep longer data of trends. See also History and trends.
Trend storage period	Select either: Do not keep trends - trends are not stored. This setting cannot be overridden by global housekeeper settings. Storage period - specify the duration of keeping aggregated (hourly min, max, avg, count) history in the database (1 day to 25 years). Older data will be removed by the housekeeper. Stored in seconds. Time suffixes are supported, e.g. 24h, 1d. User macros are supported. The Storage period value can be overridden globally in Administration → General → Housekeeper. If a global overriding setting exists, a green info icon is displayed. If you position your mouse on it, a warning message is displayed, e. g. Overridden by global housekeeper settings (7d). Note: Keeping trends is not available for non-numeric data - character, log and text. See also History and trends.
Show value	Apply value mapping to this item. Value mapping does not change received values, it is for displaying data only. It works with Numeric(unsigned), Numeric(float) and Character items. 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. This field is not available if Type of information is set to 'Log'.
Description	Enter an item description.
Enabled	Mark the checkbox to enable the item so it will be processed.

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:

Unit blacklisting

By default, specifying a unit for an item results in a multiplier prefix being added - for example, an incoming value '2048' with unit 'B' would be displayed as '2KB'.

Any unit, however, can be prevented from being converted by using a ! prefix, for example !B. To better illustrate how the conversion works with and without the blacklisting, see the following examples of values and units:

1024 !B → 1024 B
       1024 B → 1 KB
       61 !s → 61 s
       61 s → 1m 1s
       0 !uptime → 0 uptime
       0 uptime → 00:00:00
       0 !! → 0 !
       0 ! → 0

Item value preprocessing

The Preprocessing tab allows to define transformation rules for the received values. One or several transformations are possible before saving values to the database. Transformations are executed in the order in which they are defined. Preprocessing is done either by Zabbix server or by Zabbix proxy (for items monitored by proxy).

See also:

• Preprocessing details
• Preprocessing usage examples

User macros and user macros with context are supported in item value preprocessing parameters, including JavaScript code.

For change and throttling preprocessing steps Zabbix has to remember the last value to calculate/compare the new value as required. If Zabbix server is restarted or there is any change to preprocessing steps the last value of the corresponding item is reset, resulting in:

• for Simple change, Change per second steps - the next value will be ignored, because there is no previous value to calculated change from;
• for Discard unchanged. Discard unchanged with heartbeat steps - the next value will never be discarded, even if it should have been because of discarding rules.

Custom script limit

Available custom script length depends on the database used:

Testing preprocessing steps

Testing preprocessing steps is useful to make sure that complex preprocessing pipelines yield the results that are expected from them, without waiting for the item value to be received and preprocessed.

Each preprocessing step can be tested individually as well as all steps can be tested together. When you click on Test or Test all steps button respectively in the Actions block, a testing window is opened.

Click on Test to see the result after each preprocessing step.

Test values are stored between test sessions for either individual steps or all steps, allowing user to change preprocessing steps or item configuration and then return to the testing window without having to re-enter information. Values are lost on a page refresh though.

The testing is done by Zabbix server. The frontend sends a corresponding request to the server and waits for the result. The request contains the input value and preprocessing steps (with expanded user macros). For Change and Throttling steps, an optional previous value and time can be specified. The server responds with results for each preprocessing step.

Technical connection errors are displayed as error box at the top of the testing window.

Form buttons

Buttons at the bottom of the form allow to perform several operations.

	Add an item. This button is only available for new items.
	Update the properties of an item.
	Create another item based on the properties of the current item.
	Execute a check for a new item value immediately. Supported for passive checks only (see more details). Note that when checking for a value immediately, configuration cache is not updated, thus the value will not reflect very recent changes to item configuration.
	Delete the item history and trends.
	Delete the item.
	Cancel the editing of item properties.

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.