Scripted metric aggregation

Mon, 01 Jan 0001 00:00:00 +0000

Scripted metric aggregation #

A metrics aggregation whose result is computed by your own scripts, in four phases, running on Pizza’s sandboxed script engine (see the script language reference).

How it works #

One state map per segment, folded once at the end:

Phase	Runs	Scope
`init_script`	once per segment	`state`, `params`
`map_script`	once per document	`state`, `doc`, `params`
`combine_script`	once per segment	`state`, `params`
`reduce_script`	once, at the end	`states`, `params`

state is a map you own — initialize it in init_script, accumulate into it in map_script. combine_script folds one segment’s state into a single value (a script that ends in a statement returns the state itself, the default when combine_script is omitted). reduce_script receives all combined values as the states array; if it is omitted, a single state passes through unchanged and several come back as an array — the parts, rather than a wrong merge. Builds without the scripting feature return null for the whole aggregation.

Scripted_metric on INFINI Pizza

Scripted metric aggregation

Scripted metric aggregation #

How it works #