I'm just migrating my application from ES 7.17 to ES 8.8.2 and faced one issue.
I'm using ESSingleNodeTestCase to check my implementation.
My application uses Java API Client 8.8.
I figured out how to run HTTP inside tests and most of tests run correctly except all using _delete_by_query.
Details using 'co.elastic.clients.elasticsearch.core.DeleteByQueryRequest':
Response: 400 Bad Request
co.elastic.clients.util.MissingRequiredPropertyException: Missing required property 'ErrorResponse.status'
I checked it carefully and using application it works OK but using this embedded ES it doesn't.
I found information that I should add ReindexPluggin but unfortunately there is no implementation for ES 8.X here.
I found that for Netty4Plugin instead of old one there is a new project for 8.X version here.
Is there something similar for ReindexPlugin or am I doing something wrong here ?