On the first step user provides algorithm with one or more data
sources. Those sources may contain different versions for different
products, and on this stage algorithm resolves those sources into
in-memory structures - usually this will mean just reading files and
$ref references. The result of this phase is jsut a
collection of structures (one for every source) that may contain
This phase simply validates obtained structures to ensure they are valid instances of ElasticSearch schema.
This phase is intended to dispose any necessity of processing in schema. It walks through all entities, finds templates and inherited entities, then creates template derivatives / fills inherited entities and removes all templates, after that it resolves all parameters (see parameter resolution procedure below) for every entity in schema. The result of such operation is a schema without parameter maps - all required parameters have to be contained within entities themselves.
During this phase proccessor builds schema for target products and version. For each product it calculates target state, after which it is merged with products current one inherits. After all products schemas have been finished, they are merged together. Schema builder should raise errors for any conflicts between different products on this phase.
Parameter resolution procedure
Parameter resolution procedure is too simple but should be highlighted
as well. Whenever entity X requests parameter Y, resolver walks up
the tree from that entity, trying to find Y in
parameters element on
every level. After hierarchy has been completed, it creates new blank
parameter, overwrites it with properties from every parameter in
hierarchy (starting from the “ground”), and returns the result.