Sum functions
The sum functions detect anomalies when the sum of a field in a bucket is anomalous.
If you want to monitor unusually high totals, use high-sided functions.
If want to look at drops in totals, use low-sided functions.
If your data is sparse, usenon_null_sum
functions. Buckets without values are ignored; buckets with a zero value are analyzed.
The machine learning features include the following sum functions:
Thesum
function detects anomalies where the sum of a field in a bucket is anomalous.
If you want to monitor unusually high sum values, use thehigh_sum
function.
If you want to monitor unusually low sum values, use thelow_sum
function.
These functions support the following properties:
field_name
(required)by_field_name
(optional)over_field_name
(optional)partition_field_name
(optional)
For more information about those properties, see thecreate anomaly detection jobs API.
{ "function" : "sum", "field_name" : "expenses", "by_field_name" : "costcenter", "over_field_name" : "employee"}
If you use thissum
function in a detector in your anomaly detection job, it models total expenses per employees for each cost center. For each time bucket, it detects when an employee’s expenses are unusual for a cost center compared to other employees.
{ "function" : "high_sum", "field_name" : "cs_bytes", "over_field_name" : "cs_host"}
If you use thishigh_sum
function in a detector in your anomaly detection job, it models totalcs_bytes
. It detectscs_hosts
that transfer unusually high volumes compared to othercs_hosts
. This example looks for volumes of data transferred from a client to a server on the internet that are unusual compared to other clients. This scenario could be useful to detect data exfiltration or to find users that are abusing internet privileges.
Thenon_null_sum
function is useful if your data is sparse. Buckets without values are ignored and buckets with a zero value are analyzed.
If you want to monitor unusually high totals, use thehigh_non_null_sum
function.
If you want to look at drops in totals, use thelow_non_null_sum
function.
These functions support the following properties:
field_name
(required)by_field_name
(optional)partition_field_name
(optional)
For more information about those properties, see thecreate anomaly detection jobs API.
Population analysis (that is to say, use of theover_field_name
property) is not applicable for this function.
{ "function" : "high_non_null_sum", "field_name" : "amount_approved", "by_field_name" : "employee"}
If you use thishigh_non_null_sum
function in a detector in your anomaly detection job, it models the totalamount_approved
for each employee. It ignores any buckets where the amount is null. It detects employees who approve unusually high amounts compared to their past behavior.