Calculated Fields Expression Language
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feel free to reach out to us!Basic syntax and language constructs
Construct | Syntax and Notation |
---|
Reserved attribute or tag named tag | tag (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 y | func(x, y) |
Operator For example, a binary operator * with operands x and y . | x*y |
Operators
The available operators in order of precedence:
Operator | Description |
---|
() | 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 |
&& , AND | Logical AND |
|| , OR | Logical OR |
Functions
The available functions are categorized as follows:
Arithmetic
abs(num value)
Returns the absolute value of a number.
Example
Example | Formula | Result |
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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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
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
Example | Formula | Result |
---|
A log event has the following attributes: - @users_online = 5 - @max_capacity = 0 | is_null(@users_online / @max_capacity) | “true” |
Further reading
Additional helpful documentation, links, and articles: