Zabbix Documentation 3.0

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manual:appendix:triggers:functions

1 Supported trigger functions

All functions supported in trigger expressions are listed here.

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

For example:
(previous value;last 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 - evaluation period 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) or #num - the Nth most recent value
mask (mandatory) - 64-bit unsigned integer (0 - 18446744073709551615)
time_shift (optional) - see avg()
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 last and previous values. Supported value types: float, int, str, text, log

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

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 - evaluation period 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 (supported since Zabbix 2.2.0).

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

time_shift (optional) - see avg()
Supported value types: float, integer, string, text, log
Float items match with the precision of 0.000001.

With band as third parameter, the second 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 '/').

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.
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 - evaluation period in seconds or in latest collected values specified (preceded by a hash mark)
time_shift (optional) - see avg()
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 - evaluation period in seconds or in latest collected values specified (preceded by a hash mark)
time_shift (optional) - see avg()
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 999999999999.9999 or less than -999999999999.9999, return value is cropped to 999999999999.9999 or -999999999999.9999 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.
See also additional information on predictive trigger functions.
fuzzytime (sec)
Checking how much an item timestamp value differs from the Zabbix server time. sec - seconds Supported value types: float, int

Returns:
0 - if difference between item timestamp value and Zabbix server timestamp is over T seconds
1 - otherwise.

Usually used with system.localtime to check that local time is in sync with local time of Zabbix server.
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
iregexp (pattern,<sec|#num>)
This function is a non case-sensitive analogue of regexp(). see regexp() Supported value types: str, log, text
last (sec|#num,<time_shift>)
The most recent value. sec (ignored) or #num - the Nth most recent value
time_shift (optional) - see avg()
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 - regular expression describing the required pattern, POSIX extended 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 parameter. pattern - required string 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 - evaluation period in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - see avg()
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 - evaluation period in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - see avg()
Supported value types: float, int

The time_shift parameter is supported since Zabbix 1.8.2.
nodata (sec)
Checking for no data received. sec - evaluation period in seconds. The period should not be less than 30 seconds.

nodata(0) is disallowed since Zabbix 3.0.6.
Supported value types: any

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

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.
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 - evaluation period in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - see avg()
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 - regular expression, POSIX extended style.
sec or #num (optional) - evaluation period 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 - required string
sec or #num (optional) - evaluation period 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.
strlen (sec|#num,<time_shift>)
Length of the latest (most recent) value in characters (not bytes). sec (ignored) or #num - the Nth most recent value
time_shift (optional) - see avg()
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 - evaluation period in seconds or in latest collected values (preceded by a hash mark)
time_shift (optional) - see avg()
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 - evaluation period in seconds or in latest collected values specified (preceded by a hash mark)
time_shift (optional) - see avg()
threshold - value to reach
fit (optional) - see forecast()
Supported value types: float, int

If value to return is larger than 999999999999.9999, return value is cropped to 999999999999.9999.

Returns 999999999999.9999 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.
See also additional information on predictive trigger functions.

1) All functions return numeric values only. Comparison to strings is not supported, for example.
2) Some of the functions cannot be used for non-numeric parameters!
3) String arguments should be double quoted. Otherwise, they might get misinterpreted.