My team are using Apache Solr for years, we have a plan to migrate the actual infrastructure to AWS and update our current version (6.6) to a newer one (8.8), but, in the transition, we are having performance problems not presented in the actual infrastructure.
What we mainly have figured out is that using the parameters bf which value is something like product(product(bi_color_family_size_weighted_sku_availability_ratio,1),sum(product(scale(analytics_revenue,0.1,2),1.3),sum(product(outlet_products_i,-0.15),product(sale_products_i,0)))) and group in true we are getting very slow response times compared when we disable some of those parameters:
Enabling bf parameters we get between 530 and 550 ms and disabling bf parameters, between 17-18 ms. (Taking the QTime field in the response body).
It's worth saying that we already installed Solr 8.8 in the actual infrastructure and we are getting similar bad performance results.
That's because the use of some functions in the BF parameter can affect the performance, like scale or map.
You should avoid using these functions