More R Services Internals Spelunking

Niels Berglund continues his series on R Services internals:

What happens is that straight after the AuthenticateConnection you will hit the WriteAsync breakpoint twice, the same way as we see in Code Snippet 4. The first hit at WriteAsync sort of makes sense, as it ties up with the call-stack we see in Code Snippet 5. But what about the second WriteAsync (the one that causes the second package to be sent), where does that come from? To try to figure that out, we start with the call-stack for that particular WriteAsync.

Execute the code in Code Snippet 1 again, and continue to the second WriteAsync. When you hit the breakpoint do a kc again. The call-stack should now look somewhat like this (this time it is the full call-stack):

It’s interesting the kind of stuff you can find with Wireshark and a debugger.

Related Posts

Building Dynamic Row Headers With ML Services

Dave Mason tries to get around his RESULT SETS limitation when using SQL Server Machine Learning Services: The columns in the data frame clearly have names, but SQL Server isn’t using them. The data frame columns have types in R too (more on this in a moment). Now that makes me wonder about the data […]

Read More

Defining Result Sets With ML Services

Dave Mason covers a pain point in SQL Server Machine Learning Services: The example above is so simple, defining the RESULT SETS poses no problems. But what if the format of the output isn’t known at design time? R (or Python) might take the input data set and add, remove, or change columns conditionally. Further, […]

Read More


October 2017
« Sep Nov »