Dedupe events

Configuration Options

Required Options

inputs(required)

A list of upstream source or transform IDs. Wildcards (*) are supported.

See configuration for more info.

TypeSyntaxDefaultExample
arrayliteral["my-source-or-transform-id","prefix-*"]
fields(required)

Options controlling what fields to match against.

TypeSyntaxDefaultExample
hashliteral[]
type(required)

The component type. This is a required field for all components and tells Vector which component to use.

TypeSyntaxDefaultExample
stringliteral["dedupe"]

Advanced Options

cache(optional)

Options controlling how we cache recent Events for future duplicate checking.

TypeSyntaxDefaultExample
hash[]

How it Works

Cache Behavior

This transform is backed by an LRU cache of size cache.num_events. That means that this transform will cache information in memory for the last cache.num_events Events that it has processed. Entries will be removed from the cache in the order they were inserted. If an Event is received that is considered a duplicate of an Event already in the cache that will put that event back to the head of the cache and reset its place in line, making it once again last entry in line to be evicted.

Memory Usage Details

Each entry in the cache corresponds to an incoming Event and contains a copy of the 'value' data for all fields in the Event being considered for matching. When using fields.match this will be the list of fields specified in that configuration option. When using fields.ignore that will include all fields present in the incoming event except those specified in fields.ignore. Each entry also uses a single byte per field to store the type information of that field. When using fields.ignore each cache entry additionally stores a copy of each field name being considered for matching. When using fields.match storing the field names is not necessary.

Memory Utilization Estimation

If you want to estimate the memory requirements of this transform for your dataset, you can do so with these formulas:

When using fields.match:

Sum(the average size of the *data* (but not including the field name) for each field in `fields.match`) * `cache.num_events`

When using fields.ignore:

(Sum(the average size of each incoming Event) - (the average size of the field name *and* value for each field in `fields.ignore`)) * `cache.num_events`

State

This component is stateful, meaning its behavior changes based on previous inputs (events). State is not preserved across restarts, therefore state-dependent behavior will reset between restarts and depend on the inputs (events) received since the most recent restart.

Missing Fields

Fields with explicit null values will always be considered different than if that field was omitted entirely. For example, if you run this transform with fields.match = ["a"], the event "{a: null, b:5}" will be considered different to the event "{b:5}".