Trying to wrap my head around what's going on under the hood when integration services is installed, and how that relates to SQL instances on the same machine.
Currently we are aiming to have a full BI stack with each component (SQL Server containing DW, SSAS and SSIS) on separate VMs so resource requirements can be siloed. We want to use the project deployment model for SSIS so are targetting SSISDB rather than MSDB, but the server with SSIS installed doesn't have a SQL instance to host SSISDB, so currently it's installed on the SQL box.
My question is, is it necessary to install a SQL instance on the SSIS box in order to host SSISDB or can it reside just within the integration services instance somehow? If so, does that mean that connecting to the SSIS instance through SSMS is just a legacy feature to manage MSDB or file system packages?
This isn't a question about licensing, it's about infrastructure.