Decouple reactive mongo bits from blocking MongoClient [DATAMONGO-1919]

[spring-projects-issues]

Madhura Bhave opened DATAMONGO-1919 and commented

See spring-projects/spring-boot#12407 (comment)

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Issue Links:

• DATAMONGO-1928 Index creation through ReactiveMongoTemplate uses blocking methods
  ("depends on")

Referenced from: pull request #572

0 votes, 5 watchers

[spring-projects-issues]

Mark Paluch commented

Imperative and reactive execution models have a coupling in DBRef resolution as the resolution is handled by MappingMongoConverter. Our converters assume an imperative programming model hence we can't easily break up this assumption without a rewrite of the involved components and we can't introduce reactive types as they aren't required for imperative programming models.

Therefore, we need to provide a reactive variant of DbRefResolver that reports exceptions on @DBRef resolution (e.g. extend ReactiveMongoTemplate.NO_OP_REF_RESOLVER).

MongoSimpleTypes uses org.bson.types.CodeWScope which is a legacy type supported only through the legacy driver package. We should conditionally include that type and consider adding its successor org.bson.types.CodeWScope.

We also use blocking code in IndexOperationsAdapter to bridge imperative to reactive execution. This will cause issues if we use a reactive-only approach. We should either move index creation to a different place, make it reactive or disable index creation for reactive-only use