Calculated Fields Expression Language

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Basic syntax and language constructs

ConstructSyntax and Notation
Reserved attribute or tag named tagtag (no prefix required)
Attribute named attr@attr (use an @ prefix)
Calculated field named field#field (use a # prefix)
String literal (quote)
For example, text or Quoted "text".
"text"
"Quoted \"text\""
(Log Search Syntax applies)
Numeric literal (number)
For example, ten.
10
Function named func with parameters x and yfunc(x, y)
Operator
For example, a binary operator * with operands x and y.
x*y

Operators

The available operators in order of precedence:

OperatorDescription
()A grouping or function call
!, NOT, -A logical or arithmetic negation
^, %Exponentiation, Modulo
*, /Multiplication, division
+, -Addition, subtraction
<, <=, >, >=Less than, less than or equal to, greater than, greater than or equal to
==, !=Match, does not match
&&, ANDLogical AND
||, ORLogical OR

Functions

The available functions are categorized as follows:

Arithmetic

abs(num value)

Returns the absolute value of a number.

Example
ExampleFormulaResult
A log event has the following attributes:
- @client_latency = 2
- @server_latency = 3
#discrepancy = abs(@client_latency - @server_latency)#discrepancy = 1

ceil(num value)

Rounds number up to the nearest integer.

Example
ExampleFormulaResult
A log event has the following attribute:
@value = 2.2
#rounded_up = ceil(@value)#rounded_up = 3

floor(num value)

Rounds number down to the nearest integer.

Example
ExampleFormulaResult
A log event has the following attribute:
@value = 9.99
#rounded_down = floor(@value)#rounded_down = 9

max(num value, [ num value, …])

Finds maximum value amongst a set of numbers.

Example
ExampleFormulaResult
A log event has the following attribute:
@CPU_temperatures = [-1, 1, 5, 5]
#highest_temp = max(@CPU_temperatures)#highest_temp = 5

min(num value, [num value, …])

Finds the minimum value amongst a set of numbers.

Example
ExampleFormulaResult
A log event has the following attribute:
@CPU_temperatures = [-1, 1, 5, 5]
#lowest_temp = min(@CPU_temperatures)#lowest_temp = -1

round(num value, int precision)

Rounds a number. Optionally, define how many decimal places to maintain.

Example
ExampleFormulaResult
A log event has the following attribute:
@value = -1234.01
#rounded_to_tens = round(@value, -1)#rounded_to_tens = -1230

String

concat(str string [str string, expr value, …])

Combines multiple values into a single string.

Example
ExampleFormulaResult
A log event has the following attributes:
- @city = “Paris”
- @country = “France”
#region = concat(@city, ", ", @country)#region = “Paris, France”

lower(str string)

Converts string to lowercase.

Example
ExampleFormulaResult
A log event has the following attribute:
@first_name = “Bob”
#lower_name = lower(@first_name)#lower_name = “bob”

left(str string, int num_chars)

Extracts a portion of text from the beginning of a string.

Example
ExampleFormulaResult
A log event has the following attribute:
@price = “USD10.50”
#currency = left(@price, 3)#currency = “USD”

proper(str string)

Converts string to proper case.

Example
ExampleFormulaResult
A log event has the following attribute:
@address = “123 main st”
#formatted_address = proper(@address)#formatted_address = “123 Main St”

split_before(str string, str separator, int occurrence)

Extracts the portion of text preceding a certain pattern in a string.

Example
ExampleFormulaResult
A log event has the following attribute:
@url = "www.example.com/path/to/split"
#url_extraction = split_before(@url, "/", 1)#url_extraction = "www.example.com/path"
#url_extraction = split_before(@url, "/", 2)#url_extraction = "www.example.com/path/to"

split_after(str string, str separator, int occurrence)

Extracts the portion of text following a certain pattern in a string.

Example
ExampleFormulaResult
A log event has the following attribute:
@url = "www.example.com/path/to/split"
#url_extraction = split_after(@url, "/", 1)#url_extraction = "path/to/split"
#url_extraction = split_after(@url, "/", 2)#url_extraction = "to/split"

substring(str string, int start, int length)

Extracts a portion of text from the middle of a string.

Example
ExampleFormulaResult
A log event has the following attribute:
@price = “USD10.50”
#dollar_value = substring(@price, 2, 2)#dollar_value = “10”

right(str string, int num_chars)

Extracts a portion of text from the end of a string.

Example
ExampleFormulaResult
A log event has the following attribute:
@price = “USD10.50”
#cent_value = right(@price, 2)#cent_value = “50”

textjoin(str delimiter, bool ignore_empty, str string [str string, expr value, …])

Combines multiple values into a single string with a delimiter in between.

Example
ExampleFormulaResult
A log event has the following attributes:
- @city = “Paris”
- @country = “France”
#region = textjoin(", ", "false", @city, @country)#region = “Paris, France”

upper(str string)

Converts string to uppercase.

Example
ExampleFormulaResult
A log event has the following attribute: @first_name = “Bob”#upper_name = upper(@first_name)#upper_name = “BOB”

Logical

if(expr condition, expr if_true, expr if_false)

Evaluates a condition and returns a value accordingly.

Example
ExampleFormulaResult
A log event has the following attributes:
- @location = “Paris, France”
- @home = “New York, USA”
#abroad = if(@location == @home, "false", "true")#abroad = “true”

is_null(expr value)

Checks if an attribute or expression is null.

Example
ExampleFormulaResult
A log event has the following attributes:
- @users_online = 5
- @max_capacity = 0
is_null(@users_online / @max_capacity)“true”

Further reading

추가 유용한 문서, 링크 및 기사:

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