Apache Ignite as linked Server in SQLServer?
Maybe you don't have tables for your caches. By default, Apache Ignite will not create tables in its caches - i.e. they are not mapped to SQL but work in key-value mode.

There are basically three options to make tables in Ignite - CREATE TABLE, Query Entities, and Indexed Types + annotations.

You can validate it by connecting to cluster with built-in sqlline utility and then issuing !tables command.