base/frameworks/sumstats/main.bro

SumStats

The summary statistics framework provides a way to summarize large streams of data into simple reduced measurements.

Namespace:SumStats Source File:/scripts/base/frameworks/sumstats/main.bro

Summary

Types

SumStats::Calculation: enum	Type to represent the calculations that are available.
SumStats::Key: record	Represents a thing which is having summarization results collected for it.
SumStats::Observation: record	Represents data being added for a single observation.
SumStats::Reducer: record	Represents a reducer.
SumStats::Result: table	Type to store a table of results for multiple reducers indexed by observation stream identifier.
SumStats::ResultTable: table	Type to store a table of sumstats results indexed by keys.
SumStats::ResultVal: record	Result calculated for an observation stream fed into a reducer.
SumStats::SumStat: record	Represents a SumStat, which consists of an aggregation of reducers along with mechanisms to handle various situations like the epoch ending or thresholds being crossed.

Redefinitions

SumStats::Reducer: record

Functions

SumStats::create: function	Create a summary statistic.
SumStats::key2str: function	Helper function to represent a SumStats::Key value as a simple string.
SumStats::observe: function	Add data into an observation stream.
SumStats::request_key: function	Dynamically request a sumstat key.

Detailed Interface

Types

SumStats::Calculation

Type:

enum

SumStats::PLACEHOLDER

SumStats::AVERAGE

(present if base/frameworks/sumstats/plugins/average.bro is loaded)

Calculate the average of the values.

SumStats::HLL_UNIQUE

(present if base/frameworks/sumstats/plugins/hll_unique.bro is loaded)

Calculate the number of unique values.

SumStats::LAST

(present if base/frameworks/sumstats/plugins/last.bro is loaded)

Keep last X observations in a queue.

SumStats::MAX

(present if base/frameworks/sumstats/plugins/max.bro is loaded)

Find the maximum value.

SumStats::MIN

(present if base/frameworks/sumstats/plugins/min.bro is loaded)

Find the minimum value.

SumStats::SAMPLE

(present if base/frameworks/sumstats/plugins/sample.bro is loaded)

Get uniquely distributed random samples from the observation stream.

SumStats::VARIANCE

(present if base/frameworks/sumstats/plugins/variance.bro is loaded)

Calculate the variance of the values.

SumStats::STD_DEV

(present if base/frameworks/sumstats/plugins/std-dev.bro is loaded)

Calculate the standard deviation of the values.

SumStats::SUM

(present if base/frameworks/sumstats/plugins/sum.bro is loaded)

Calculate the sum of the values. For string values, this will be the number of strings.

SumStats::TOPK

(present if base/frameworks/sumstats/plugins/topk.bro is loaded)

Keep a top-k list of values.

SumStats::UNIQUE

(present if base/frameworks/sumstats/plugins/unique.bro is loaded)

Calculate the number of unique values.

Type to represent the calculations that are available. The calculations are all defined as plugins.

SumStats::Key

Type:

record

str: string &optional

A non-address related summarization or a sub-key for an address based summarization. An example might be successful SSH connections by client IP address where the client string would be the key value. Another example might be number of HTTP requests to a particular value in a Host header. This is an example of a non-host based metric since multiple IP addresses could respond for the same Host header value.

host: addr &optional

Host is the value to which this metric applies.

Represents a thing which is having summarization results collected for it.

SumStats::Observation

Type:

record

num: count &optional

Count value.

dbl: double &optional

Double value.

str: string &optional

String value.

Represents data being added for a single observation. Only supply a single field at a time!

SumStats::Reducer

Type:

record

stream: string

Observation stream identifier for the reducer to attach to.

apply: set [SumStats::Calculation]

The calculations to perform on the data points.

pred: function (key: SumStats::Key, obs: SumStats::Observation) : bool &optional

A predicate so that you can decide per key if you would like to accept the data being inserted.

normalize_key: function (key: SumStats::Key) : SumStats::Key &optional

A function to normalize the key. This can be used to aggregate or normalize the entire key.

ssname: string &optional

calc_funcs: vector of SumStats::Calculation &optional

hll_error_margin: double &default = 0.01 &optional

(present if base/frameworks/sumstats/plugins/hll_unique.bro is loaded)

The error margin for HLL.

hll_confidence: double &default = 0.95 &optional

(present if base/frameworks/sumstats/plugins/hll_unique.bro is loaded)

The confidence for HLL.

num_last_elements: count &default = 0 &optional

(present if base/frameworks/sumstats/plugins/last.bro is loaded)

Number of elements to keep.

num_samples: count &default = 0 &optional

(present if base/frameworks/sumstats/plugins/sample.bro is loaded)

The number of sample Observations to collect.

topk_size: count &default = 500 &optional

(present if base/frameworks/sumstats/plugins/topk.bro is loaded)

Number of elements to keep in the top-k list.

unique_max: count &optional

(present if base/frameworks/sumstats/plugins/unique.bro is loaded)

Maximum number of unique values to store.

Represents a reducer.

SumStats::Result

Type:table [string] of SumStats::ResultVal

Type to store a table of results for multiple reducers indexed by observation stream identifier.

SumStats::ResultTable

Type:table [SumStats::Key] of SumStats::Result

Type to store a table of sumstats results indexed by keys.

SumStats::ResultVal

Type:

record

begin: time

The time when the first observation was added to this result value.

end: time

The time when the last observation was added to this result value.

num: count &default = 0 &optional

The number of observations received.

average: double &optional

(present if base/frameworks/sumstats/plugins/average.bro is loaded)

For numeric data, this is the average of all values.

hll_unique: count &default = 0 &optional

(present if base/frameworks/sumstats/plugins/hll_unique.bro is loaded)

If cardinality is being tracked, the number of unique items is tracked here.

card: opaque of cardinality &optional

(present if base/frameworks/sumstats/plugins/hll_unique.bro is loaded)

hll_error_margin: double &optional

(present if base/frameworks/sumstats/plugins/hll_unique.bro is loaded)

hll_confidence: double &optional

(present if base/frameworks/sumstats/plugins/hll_unique.bro is loaded)

last_elements: Queue::Queue &optional

(present if base/frameworks/sumstats/plugins/last.bro is loaded)

This is the queue where elements are maintained. Use the SumStats::get_last function to get a vector of the current element values.

max: double &optional

(present if base/frameworks/sumstats/plugins/max.bro is loaded)

For numeric data, this tracks the maximum value.

min: double &optional

(present if base/frameworks/sumstats/plugins/min.bro is loaded)

For numeric data, this tracks the minimum value.

samples: vector of SumStats::Observation &default = [] &optional

(present if base/frameworks/sumstats/plugins/sample.bro is loaded)

This is the vector in which the samples are maintained.

sample_elements: count &default = 0 &optional

(present if base/frameworks/sumstats/plugins/sample.bro is loaded)

Number of total observed elements.

num_samples: count &default = 0 &optional

(present if base/frameworks/sumstats/plugins/sample.bro is loaded)

variance: double &optional

(present if base/frameworks/sumstats/plugins/variance.bro is loaded)

For numeric data, this is the variance.

prev_avg: double &optional

(present if base/frameworks/sumstats/plugins/variance.bro is loaded)

var_s: double &default = 0.0 &optional

(present if base/frameworks/sumstats/plugins/variance.bro is loaded)

std_dev: double &default = 0.0 &optional

(present if base/frameworks/sumstats/plugins/std-dev.bro is loaded)

For numeric data, this calculates the standard deviation.

sum: double &default = 0.0 &optional

(present if base/frameworks/sumstats/plugins/sum.bro is loaded)

For numeric data, this tracks the sum of all values.

topk: opaque of topk &optional

(present if base/frameworks/sumstats/plugins/topk.bro is loaded)

A handle which can be passed to some built-in functions to get the top-k results.

unique: count &default = 0 &optional

(present if base/frameworks/sumstats/plugins/unique.bro is loaded)

If cardinality is being tracked, the number of unique values is tracked here.

unique_max: count &optional

(present if base/frameworks/sumstats/plugins/unique.bro is loaded)

unique_vals: set [SumStats::Observation] &optional

(present if base/frameworks/sumstats/plugins/unique.bro is loaded)

Result calculated for an observation stream fed into a reducer. Most of the fields are added by plugins.

SumStats::SumStat

Type:

record

name: string

An arbitrary name for the sumstat so that it can be referred to later.

epoch: interval

The interval at which this filter should be “broken” and the epoch_result callback called. The results are also reset at this time so any threshold based detection needs to be set to a value that should be expected to happen within this epoch.

reducers: set [SumStats::Reducer]

The reducers for the SumStat.

threshold_val: function (key: SumStats::Key, result: SumStats::Result) : double &optional

A function that will be called once for each observation in order to calculate a value from the SumStats::Result structure which will be used for thresholding. This function is required if a threshold value or a threshold_series is given.

threshold: double &optional

The threshold value for calling the threshold_crossed callback. If you need more than one threshold value, then use threshold_series instead.

threshold_series: vector of double &optional

A series of thresholds for calling the threshold_crossed callback. These thresholds must be listed in ascending order, because a threshold is not checked until the preceding one has been crossed.

threshold_crossed: function (key: SumStats::Key, result: SumStats::Result) : void &optional

A callback that is called when a threshold is crossed. A threshold is crossed when the value returned from threshold_val is greater than or equal to the threshold value, but only the first time this happens within an epoch.

epoch_result: function (ts: time, key: SumStats::Key, result: SumStats::Result) : void &optional

A callback that receives each of the results at the end of the analysis epoch. The function will be called once for each key.

epoch_finished: function (ts: time) : void &optional

A callback that will be called when a single collection interval is completed. The ts value will be the time of when the collection started.

Represents a SumStat, which consists of an aggregation of reducers along with mechanisms to handle various situations like the epoch ending or thresholds being crossed.

It’s best to not access any global state outside of the variables given to the callbacks because there is no assurance provided as to where the callbacks will be executed on clusters.

Functions

SumStats::create

Type:function (ss: SumStats::SumStat) : void

Create a summary statistic.

Ss:The SumStat to create.

SumStats::key2str

Type:function (key: SumStats::Key) : string

Helper function to represent a SumStats::Key value as a simple string.

Key:The metric key that is to be converted into a string. Returns:A string representation of the metric key.

SumStats::observe

Type:function (id: string, key: SumStats::Key, obs: SumStats::Observation) : void

Add data into an observation stream. This should be called when a script has measured some point value.

Id:The observation stream identifier that the data point represents. Key:The key that the value is related to. Obs:The data point to send into the stream.

SumStats::request_key

Type:function (ss_name: string, key: SumStats::Key) : SumStats::Result

Dynamically request a sumstat key. This function should be used sparingly and not as a replacement for the callbacks from the SumStats::SumStat record. The function is only available for use within “when” statements as an asynchronous function.

Ss_name:SumStat name. Key:The SumStat key being requested. Returns:The result for the requested sumstat key.