Roman, your description seems fine to me. I don't like CLIENT SETNAME. This may confuse redis users as well.
Why do you say that we will have only 8 databases. As far as I remember there are 16 by default and this is configurable and can be increased as well. Can you please check this? To get access to per-connection meta you will need to add "addMeta/meta/removeMeta" methods to org.apache.ignite.internal.processors.rest.request.GridRestRequest to provide access to org.apache.ignite.internal.util.nio.GridNioSession's meta related methods or to attributes' related methods of HttpSession in depending on where request is created.. --Yakov