Splunk® Data Stream Processor

DSP Function Reference

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DSP Functions by category

Use the following section as a reference of available streaming and scalar functions.

Streaming functions

These functions are visible in the UI. Streaming functions are full nodes in the pipeline with edges that data flows through. Data streams from one node (the streaming function) through its edge to the next node (streaming function). Streaming functions can use scalar functions.

Functions Description
Aggregate Applies one or more aggregation functions on a stream of events in a specified time window.
Aggregate and Trigger Triggers an event output based on a custom condition over a set of aggregated events.
Batch Events Batches events before sending them to an index.
Bin Puts continuous numerical values into discrete sets, or bins, by adjusting the value of <field> so that all of the items in a particular set have the same value.
Break Events Break events using a Java regular expression as a delimiter.
Eval Calculate an expression and put the resulting value into the record as a new field.
Extract Timestamp Extract a timestamp using the first rule that matches.
Fields Select a subset of fields from a record.
Filter Keep events that pass a Boolean function.
For Each (map) Transforms each record in a stream by applying a function to each element.
Group Group a stream of records by one or more field(s) and returns a grouped stream.
Merge Events Parses data received from a universal forwarder into a stream of complete events for a Splunk Index.
Mvexpand Expand the values in a multivalue field into separate events, one event for each value in the multivalue field.
Normalize (projection) Assigns an alternative name to a field or applies scalar functions to a group of fields.
Parse regex (rex) Extract or rename fields using Java regular expression-named capturing groups.
Rename Rename one or more fields.
Union Combines streams with the same input schema into one stream with all of the events of the input streams.

Streaming source and sink functions

These functions are visible in the UI and are source or sink functions.

Functions Description
Amazon CloudWatch Metrics Read data from Amazon CloudWatch Metrics.
Amazon S3 Connector Read data from Amazon S3.
Azure Event Hubs Using SAS key Read data from Azure Event Hubs Using SAS key.
Read from Splunk Firehose Reads data sent from Splunk DSP Ingest, Forwarders, and Collect API Services.
Read from Forwarders Service Reads data from the Splunk Forwarders Service.
Read from Ingest REST API Reads data from the Ingest REST API.
Read from Apache Kafka

Reads data from Apache Kafka without authentication.

Read from Apache Kafka with SSL Reads data from Apache Kafka using SSL.
Read from Amazon Kinesis Reads data from Amazon Kinesis.
Read from Amazon Kinesis (Specify Init Stream) Reads data from Amazon Kinesis, specifying where to start reading from.
Write to Index Writes data to your default, pre-configured Splunk Enterprise instance.
Write to Kafka Writes data to an authenticated Kafka topic using a Kafka connection.
Write to Kafka with SSL Writes data to an authenticated Kafka topic.
Write to Kinesis Send data to a Kinesis Stream using an AWS access key and secret key authentication.
Write to Null Writes data to a null sink.
Write to SignalFx Writes data to SignalFx.
Write to Splunk Enterprise Index Writes data to an external Splunk Enterprise index.

Scalar functions

Scalar functions are not full nodes in a pipeline, but instead, help perform certain operations inside of a streaming function. You can use scalar functions to do things like addition and subtraction, comparisons, conversions, or other similar tasks.

Scalar functions operate in the context of the streaming function that they are called in.

Function Category Function list Description
Core functions as Returns INPUT named as NAME.
cast Converts an expression from one data type to another.
contains_key Checks if a key exists in a map.
create_map Creates a new map object at runtime.
get Provides a lookup ("get") of a value in a single record.
if Assigns an expression if the value is true, and another expression if the value is false.
list Returns a list that contains the provided arguments.
literal Provides a way to wrap a literal value in a callable function.
map_flatten Accepts a nested map and flattens it with dot-concatenated field names.
map_get Returns the value corresponding to a key in the map input.
map_put Accepts a variable list of keys and values, which must have a nonzero and even length.
ucast Provides a way to cast maps and collections, regardless of the data type that the map or collection may contain.
Aggregate functions average Returns the average of the values in the field X.
count Returns the number of non-null values in a time window.
max Returns the maximum value in a time window.
mean Calculates the average (mean) of values in a time window.
min Returns the minimum value in a time window.
sum Returns the sum of values in a time window.
Arithmetic functions add Adds the left and right argument and returns the result.
divide (div) Divides the left and right arguments and returns the result.
multiply Multiplies the left and right arguments and returns the result.
mod Returns the remainder after dividing the left and right arguments.
subtract Subtracts the left and right arguments and returns the result.
Boolean scalar functions boolean and (and) Performs a Boolean AND operation on the left and right arguments and returns the result as a Boolean.
boolean not (not) Performs a Boolean NOT operation and returns the result as a Boolean.
boolean or (or) Performs a Boolean OR operation on the left and right arguments and returns the result as a Boolean.
boolean xor (xor) Performs a Boolean XOR operation on the left and right arguments and returns the result as a Boolean.
Comparison scalar functions equals (eq) Compares two values and returns LEFT == RIGHT.
greater than (gt) Compares two values and returns LEFT > RIGHT.
greater than or equal to (gte) Compares two values and returns LEFT >= RIGHT.
less than (lt) Compares two values and returns LEFT < RIGHT.
less than or equal to (lte) Compares two values and returns LEFT <= RIGHT.
Conditional scalar functions coalesce Takes a variable number of arguments and returns the first value that is not NULL.
in Returns TRUE if one of the values in a list matches a value in the field you specify.
like Returns TRUE if TEXT matches PATTERN.
null if equal (nullif) Compares two fields, A and B, and returns NULL if A = B.
validate Returns string Y corresponding to the first expression X that evaluates to FALSE.
Conversion scalar functions base64_encode Converts a byte array value to a Base64-encoded string.
base64_decode Converts a Base64-encoded string to bytes.
tostring Converts a number to a string.
to_string Converts a byte array to a String.
gzip Returns Gzipped-compressed bytes.
gunzip Decompresses a GZipped byte array.
deserialize_json_object Converts a JSON byte string into a map.
from_json_array Converts a JSON string into an array of the JSON structure, including nested keys.
from json object Converts a JSON string into a map of the JSON structure, including nested keys.
inet_aton Converts a string IPv4 or IPv6 IP address and returns the address as type Long.
inet_ntoa Converts a decimal IP address to dotted-decimal form.
parse_bool Parses a string as a boolean.
parse_double Parses a string and returns the numeric value as a Double.
parse_float Parses a string and returns the numeric value as a Float.
parse_int Parses a string as an integer.
parse long Parses a string and returns the numeric value as Long.
serialize_json Converts the current record into a JSON byte string.
serialize_json Converts a map of a JSON structure into a JSON byte array.
to_bytes Converts a string to a byte string.
to_bytes Converts a string with a character encoding you specify to a byte string.
to_json Converts a map of a JSON object's structure to a JSON string.
Cryptographic scalar functions md5 Computes and returns the MD5 hash of a byte value X.
sha1 Computes and returns the secure hash of a byte value X based on the FIPS compliant SHA-1 hash function.
sha256 Computes and returns the secure hash of a byte value X based on the FIPS compliant SHA-256 hash function.
sha512 Computes and returns the secure hash of a byte value X based on the FIPS compliant SHA-512 hash function.
Date and Time scalar functions relative_time Applies a relative time specifier to a UNIX time value.
strftime This function formats a UNIX timestamp into a human-readable timestamp.
strptime This function parses a date string into a UNIX timestamp.
time This function returns the wall-clock time, in the UNIX time format, with millisecond resolution.
Mathematical scalar functions abs Takes a number and returns its absolute value.
ceiling Rounds a number up to the next highest integer.
exp Takes a number X and returns the exponential ex.
floor Rounds a number down to the nearest whole intenger.
log Takes one or two numbers and returns the logarithm of the first argument X using the second argument Y as the base.
natural logarithm (ln) Takes a number X and returns its natural logarithm.
pi Returns the constant pi to 11 digits of precision.
power of base (pow) Takes two numbers, X and Y, and returns XY.
round value (round) Takes two numbers, X and Y, and returns X rounded to the amount of decimal places specified by Y.
round value (round) Takes a number X and returns X rounded to the nearest whole number.
sqrt Takes a number X and returns its square root.
Multivalue scalar functions mvappend Takes an arbitrary list of arguments, where each argument is a single string or a list of strings, and returns all elements as a single flattened list.
String manipulation scalar functions concat Combines the first and second strings together.
extract_grok Extracts matching groups with a Grok-compatible pattern.
extract_key_value Extract key-value pairs.
extract_regex Uses a Java regular expression to extract capturing groups from the input.
len Returns the character length of a string.
lower Converts a string to lowercase.
ltrim Takes two arguments X and Y and returns X with the characters in Y trimmed from the left side.
ltrim Takes an argument X and returns X with whitespaces removed from the left side.
match_regex Matches inputs against a pattern defined with a Java regular expression.
match_wildcard Matches inputs against a wildcard pattern.
punct Extracts punctuation from a string.
replace Performs a regex replacement on a string.
rtrim Takes two arguments X and Y and returns X with the characters in Y trimmed from the right side.
rtrim Takes an argument X and returns X with whitespaces removed from the right side.
spath Extract a value from a map or collection.
substr Returns a substring of a string. Takes two arguments.
substr Returns a substring of a string. Takes three arguments.
trim Takes two arguments X and Y and returns X with the characters in Y trimmed from both sides.
trim Takes an argument X and returns X with whitespaces removed from both sides.
upper Converts a string to uppercase.
url_decode Takes a URL string and returns the unescaped or decoded URL string.
url_encode Encodes a string for the query string parameters in a URL.
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How to use the DSP Function Reference

This documentation applies to the following versions of Splunk® Data Stream Processor: 1.0.0


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