How to access the Join Service

The Join Service processes a stream of logged data, joining each "decision tuple" with the "outcome tuple" for the same experimental unit (see MWT White Paper for more background). The Join Service is implemented via Azure Stream Analytics (ASA), as a query in the ASA query language (ASA join query).

The ASA join query can be accessed as follows. After the Decision Service is deployed, go to the corresponding "resource group" on Azure Dashboard. In the "Overview", find the list of resources, and click on the resource named "join-XXX". This opens a blade for the Join Service. In this blade, find item "query" under "job topology". This opens a blade with the code for the join query. When the Join Service is running, the query can be viewed only.

The default query provided with the Decision Service should suffice most of the time. That said, a custom query may be needed, e.g., for logging auxiliary info or for delayed reward computation. To modify the default query: stop the Join Service, go to the query and edit, then restart the Join Service.

To stop/restart the Join Service: go to the "Join Service" blade and click on "overview". On top of the "overview" blade, there are buttons ("Settings", "Start", "Stop" and "Delete"). Click on "Stop" or "Start", respectively.