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1 Supported trigger functions

All functions supported in trigger expressions are listed here.

FUNCTION
Description Parameters Comments
abschange
The amount of absolute difference between the previous and latest value. Supported value types: float, int, str, text, log

For example:
(previous value;latest value=abschange)
1;5=4
3;1=2
0;-2.5=2.5

For strings returns:
0 - values are equal
1 - values differ
avg (sec|#num,<time_shift>)
Average value of an item within the defined evaluation period. sec or #num - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: float, int

Examples:
=> avg(#5) → average value for the five latest values
=> avg(1h) → average value for an hour
=> avg(1h,1d) → average value for an hour one day ago.

The time_shift parameter is supported since Zabbix 1.8.2. It is useful when there is a need to compare the current average value with the average value time_shift seconds back.
band (<sec|#num>,mask,<time_shift>)
Value of "bitwise AND" of an item value and mask. sec (ignored, equals #1) or #num (optional) - the Nth most recent value
mask (mandatory) - 64-bit unsigned integer (0 - 18446744073709551615)
time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: int

Take note that #num works differently here than with many other functions (see last()).

Although the comparison is done in a bitwise manner, all the values must be supplied and are returned in decimal. For example, checking for the 3rd bit is done by comparing to 4, not 100.

Examples:
=> band(,12)=8 or band(,12)=4 → 3rd or 4th bit set, but not both at the same time
=> band(,20)=16 → 3rd bit not set and 5th bit set.

This function is supported since Zabbix 2.2.0.
change
The amount of difference between the previous and latest value. Supported value types: float, int, str, text, log

For example:
(previous value;latest value=change)
1;5=+4
3;1=-2
0;-2.5=-2.5

See also: abschange for comparison

For strings returns:
0 - values are equal
1 - values differ
count (sec|#num,<pattern>,<operator>,<time_shift>)
Number of values within the defined evaluation period. sec or #num - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark)
pattern (optional) - required pattern

operator (optional)

Supported operators:
eq - equal
ne - not equal
gt - greater
ge - greater or equal
lt - less
le - less or equal
like - matches if contains pattern (case-sensitive)
band - bitwise AND
regexp - case sensitive match of regular expression given in pattern
iregexp - case insensitive match of regular expression given in pattern

Note that:
eq (default), ne, gt, ge, lt, le, band, regexp, iregexp are supported for integer items
eq (default), ne, gt, ge, lt, le, regexp, iregexp are supported for float items
like (default), eq, ne, regexp, iregexp are supported for string, text and log items

time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: float, integer, string, text, log

Float items match with the precision of 2.22e-16 (since 5.0.13); before that or if database is not upgraded the precision is 0.000001.

With band as third parameter, the second pattern parameter can be specified as two numbers, separated by '/': number_to_compare_with/mask. count() calculates "bitwise AND" from the value and the mask and compares the result to number_to_compare_with. If the result of "bitwise AND" is equal to number_to_compare_with, the value is counted.
If number_to_compare_with and mask are equal, only the mask need be specified (without '/').

With regexp or iregexp as third parameter the second pattern parameter can be an ordinary or global (starting with '@') regular expression. In case of global regular expressions case sensitivity is inherited from global regular expression settings. For the purpose of regexp matching, float values will always be represented with 4 decimal digits after '.'. Also note that for large numbers difference in decimal (stored in database) and binary (used by Zabbix server) representation may affect the 4th decimal digit.

Examples:
=> count(10m) → number of values for last 10 minutes
=> count(10m,"error",eq) → number of values for last 10 minutes that equal 'error'
=> count(10m,12) → number of values for last 10 minutes that equal '12'
=> count(10m,12,gt) → number of values for last 10 minutes that are over '12'
=> count(#10,12,gt) → number of values within last 10 values that are over '12'
=> count(10m,12,gt,1d) → number of values for preceding 10 minutes up to 24 hours ago that were over '12'
=> count(10m,6/7,band) → number of values for last 10 minutes having '110' (in binary) in the 3 least significant bits.
=> count(10m,,,1d) → number of values for preceding 10 minutes up to 24 hours ago

The #num parameter is supported since Zabbix 1.6.1.
The time_shift parameter and string operators are supported since Zabbix 1.8.2.
The band operator is supported since Zabbix 2.2.0.
The regexp, iregexp operators are supported since Zabbix 3.2.0.
date
Current date in YYYYMMDD format. Supported value types: any

Example of returned value: 20150731
dayofmonth
Day of month in range of 1 to 31. Supported value types: any

This function is supported since Zabbix 1.8.5.
dayofweek
Day of week in range of 1 to 7 (Mon - 1, Sun - 7). Supported value types: any
delta (sec|#num,<time_shift>)
Difference between the maximum and minimum values within the defined evaluation period ('max()' minus 'min()'). sec or #num - maximum evaluation period1 in seconds or in latest collected values specified (preceded by a hash mark)
time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: float, int

The time_shift parameter is supported since Zabbix 1.8.2.
diff
Checking if last and previous values differ. Supported value types: float, int, str, text, log

Returns:
1 - last and previous values differ
0 - otherwise
forecast (sec|#num,<time_shift>,time,<fit>,<mode>)
Future value, max, min, delta or avg of the item. sec or #num - maximum evaluation period1 in seconds or in latest collected values specified (preceded by a hash mark)
time_shift (optional) - evaluation point is moved the number of seconds back in time
time - forecasting horizon in seconds
fit (optional) - function used to fit historical data

Supported fits:
linear - linear function
polynomialN - polynomial of degree N (1 <= N <= 6)
exponential - exponential function
logarithmic - logarithmic function
power - power function

Note that:
linear is default, polynomial1 is equivalent to linear

mode (optional) - demanded output

Supported modes:
value - value (default)
max - maximum
min - minimum
delta - max-min
avg - average

Note that:
value estimates item value at the moment now + time
max, min, delta and avg investigate item value estimate on the interval between now and now + time
Supported value types: float, int

If value to return is larger than 1.7976931348623157E+308 or less than -1.7976931348623157E+308, return value is cropped to 1.7976931348623157E+308 or -1.7976931348623157E+308 correspondingly.

Becomes not supported only if misused in expression (wrong item type, invalid parameters), otherwise returns -1 in case of errors.

Examples:
=> forecast(#10,,1h) → forecast of item value after one hour based on last 10 values
=> forecast(1h,,30m) → forecast of item value after 30 minutes based on last hour data
=> forecast(1h,1d,12h) → forecast of item after 12 hours based on one hour one day ago
=> forecast(1h,,10m,exponential) → forecast of item value after 10 minutes based on last hour data and exponential function
=> forecast(1h,,2h,polynomial3,max) → forecast of maximum value item can reach in next two hours based on last hour data and cubic (third degree) polynomial
=> forecast(#2,,-20m) → estimate the value of an item which was 20 minutes ago based on last two values (this can be more precise than using last() or prev(), especially if item is updated rarely, say, once an hour)

This function is supported since Zabbix 3.0.0.
Negative time values are supported since Zabbix 3.0.6 and 3.2.2.
See also additional information on predictive trigger functions.
fuzzytime (sec)
Checking how much the passive agent time differs from the Zabbix server/proxy time. sec - seconds Supported value types: float, int

Returns:
1 - difference between the passive item value (as timestamp) and Zabbix server/proxy timestamp is less than or equal to T seconds
0 - otherwise

Usually used with the 'system.localtime' item to check that local time is in sync with the local time of Zabbix server. Note that 'system.localtime' must be configured as a passive check.
Can be used also with vfs.file.time[/path/file,modify] key to check that file didn't get updates for long time.

Example:
=> fuzzytime(60)=0 → detect a problem if time difference is over 60 seconds

This function is not recommended for use in complex trigger expressions (with multiple items involved), because it may cause unexpected results (time difference will be measured with the most recent metric), e.g. in Host:system.localtime.fuzzytime(60)}=0 or {Host:trap.last()}<>0
iregexp (<pattern>,<sec|#num>)
This function is a non case-sensitive analog of regexp(). see regexp() Supported value types: str, log, text
last (<sec|#num>,<time_shift>)
The most recent value. sec (ignored, equals #1) or #num (optional) - the Nth most recent value
time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: float, int, str, text, log

Take note that #num works differently here than with many other functions.
For example:
last() is always equal to last(#1)
last(#3) - third most recent value (not three latest values)

Zabbix does not guarantee exact order of values if more than two values exist within one second in history.

The #num parameter is supported since Zabbix 1.6.2.
The time_shift parameter is supported since Zabbix 1.8.2.
logeventid (<pattern>)
Checking if event ID of the last log entry matches a regular expression. pattern (optional) - regular expression describing the required pattern, Perl Compatible Regular Expression (PCRE) style. Supported value types: log

Returns:
0 - does not match
1 - matches

This function is supported since Zabbix 1.8.5.
logseverity
Log severity of the last log entry. Supported value types: log

Returns:
0 - default severity
N - severity (integer, useful for Windows event logs: 1 - Information, 2 - Warning, 4 - Error, 7 - Failure Audit, 8 - Success Audit, 9 - Critical, 10 - Verbose).
Zabbix takes log severity from Information field of Windows event log.
logsource (<pattern>)
Checking if log source of the last log entry matches a regular expression. pattern (optional) - regular expression describing the required pattern, Perl Compatible Regular Expression (PCRE) style. Supported value types: log

Returns:
0 - does not match
1 - matches

Normally used for Windows event logs. For example, logsource("VMware Server").
max (sec|#num,<time_shift>)
Highest value of an item within the defined evaluation period. sec or #num - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: float, int

The time_shift parameter is supported since Zabbix 1.8.2.
min (sec|#num,<time_shift>)
Lowest value of an item within the defined evaluation period. sec or #num - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: float, int

The time_shift parameter is supported since Zabbix 1.8.2.
nodata (sec,<mode>)
Checking for no data received. sec - evaluation period in seconds.
The period should not be less than 30 seconds because the history syncer process calculates this function only every 30 seconds.

nodata(0) is disallowed.

mode - if set to strict, this function will be insensitive to proxy availability (see comments for details).
Supported value types: any

Returns:
1 - if no data received during the defined period of time
0 - otherwise

Since Zabbix 5.0, the 'nodata' triggers monitored by proxy are, by default, sensitive to proxy availability - if proxy becomes unavailable, the 'nodata' triggers will not fire immediately after a restored connection, but will skip the data for the delayed period. Note that for passive proxies suppression is activated if connection is restored more than 15 seconds and no less than 2 & ProxyUpdateFrequency seconds later. For active proxies suppression is activated if connection is restored more than 15 seconds later.

To turn off sensitiveness to proxy availability, use the second parameter, e.g.: nodata(5m,strict); in this case the function will work the same as before 5.0.0 and fire as soon as the evaluation period (five minutes) without data has past.

Note that this function will display an error if, within the period of the 1st parameter:
- there's no data and Zabbix server was restarted
- there's no data and maintenance was completed
- there's no data and the item was added or re-enabled
Errors are displayed in the Info column in trigger configuration.

This function may not work properly if there are time differences between Zabbix server, proxy and agent. See also: Time synchronization requirement.
now
Number of seconds since the Epoch (00:00:00 UTC, January 1, 1970). Supported value types: any
percentile (sec|#num,<time_shift>,percentage)
P-th percentile of a period, where P (percentage) is specified by the third parameter. sec or #num - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - evaluation point is moved the number of seconds back in time
percentage - a floating-point number between 0 and 100 (inclusive) with up to 4 digits after the decimal point
Supported value types: float, int

This function is supported since Zabbix 3.0.0.
prev
Previous value. Supported value types: float, int, str, text, log

Returns the same as last(#2).
regexp (<pattern>,<sec|#num>)
Checking if the latest (most recent) value matches regular expression. pattern (optional) - regular expression, Perl Compatible Regular Expression (PCRE) style.
sec or #num (optional) - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark). In this case, more than one value may be processed.
Supported value types: str, text, log

Returns:
1 - found
0 - otherwise

If more than one value is processed, '1' is returned if there is at least one matching value.

This function is case-sensitive.
str (<pattern>,<sec|#num>)
Finding a string in the latest (most recent) value. pattern (optional) - required string
sec or #num (optional) - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark). In this case, more than one value may be processed.
Supported value types: str, text, log

Returns:
1 - found
0 - otherwise

If more than one value is processed, '1' is returned if there is at least one matching value.

This function is case-sensitive.

Tip: You may use the 'count' function with the like operator to count string values that match a pattern.
strlen (<sec|#num>,<time_shift>)
Length of the latest (most recent) value in characters (not bytes). sec (ignored, equals #1) or #num (optional) - the Nth most recent value
time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: str, text, log

Take note that #num works differently here than with many other functions.

Examples:
=> strlen()(is equal to strlen(#1)) → length of the latest value
=> strlen(#3) → length of the third most recent value
=> strlen(,1d) → length of the most recent value one day ago.

This function is supported since Zabbix 1.8.4.
sum (sec|#num,<time_shift>)
Sum of collected values within the defined evaluation period. sec or #num - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - evaluation point is moved the number of seconds back in time
Supported value types: float, int

The time_shift parameter is supported since Zabbix 1.8.2.
time
Current time in HHMMSS format. Supported value types: any

Example of returned value: 123055
timeleft (sec|#num,<time_shift>,threshold,<fit>)
Time in seconds needed for an item to reach a specified threshold. sec or #num - maximum evaluation period1 in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - evaluation point is moved the number of seconds back in time
threshold - value to reach
fit (optional) - see forecast()
Supported value types: float, int

If value to return is larger than 1.7976931348623157E+308, return value is cropped to 1.7976931348623157E+308.

Returns 1.7976931348623157E+308 if threshold cannot be reached.

Becomes not supported only if misused in expression (wrong item type, invalid parameters), otherwise returns -1 in case of errors.

Examples:
=> timeleft(#10,,0) → time until item value reaches zero based on last 10 values
=> timeleft(1h,,100) → time until item value reaches 100 based on last hour data
=> timeleft(1h,1d,0) → time until item value reaches 0 based on one hour one day ago
=> timeleft(1h,,200,polynomial2) → time until item reaches 200 based on last hour data and assumption that item behaves like quadratic (second degree) polynomial

This function is supported since Zabbix 3.0.0.
Unit symbols in threshold parameter are supported since Zabbix 3.0.6 and 3.2.2.
See also additional information on predictive trigger functions.

Important notes:
1) Some of the functions cannot be used for non-numeric values!
2) String arguments should be double quoted. Otherwise, they might get misinterpreted.
3) For all trigger functions sec and time_shift must be an integer with an optional time unit suffix and has absolutely nothing to do with the item's data type.

Footnotes

1 The evaluation period is up to the latest collected value (not the server 'now' time). A function is evaluated as soon as at least one value is received (unless the time_shift parameter is used), i.e. Zabbix will not wait for all the values within the defined evaluation period before evaluating the function.

Functions and unsupported items

Since Zabbix 3.2, nodata(), date(), dayofmonth(), dayofweek(), now() and time() functions are calculated for unsupported items, too. Other functions require that the referenced item is in a supported state.