For some reason, sporadically something is triggering EF to loop through and query all DbSets associated with a context and return all the results. This is causing out of memory exceptions, because it's pulling literally our entire database.

We can't seem to consistently replicate this, but when we have it's been when we call SaveChangesAsync and there's been some sort of exception (like truncation).

We are trying to trace through to figure out which call is exactly triggering this, and we're adding some additional logging to help us out and figure out the problem child. Ultimately just want to know something about where this is getting called so we can look for the root cause.

My question is - what's the trigger for EF Core to do something like this? If I know the scenario of when it happens, I can try and look at our code and see where we're hitting that scenario?

We have ClientWarnings as a throw via

optionsBuilder.ConfigureWarnings(warnings => warnings.Throw(RelationalEventId.QueryClientEvaluationWarning));

So to me this shouldn't ever happen. We get no exception or anything in the logs. A snippet of the logs as it loops through every DbSet:

[Debug] Context '"Entity1"' started tracking '"SomeDbContext"' entity. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see key values.
[Debug] Context '"Entity1"' started tracking '"SomeDbContext"' entity. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see key values.
// Repeated for every row in Entity1 table

[Debug] Context '"Entity2"' started tracking '"SomeDbContext"' entity. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see key values.
[Debug] Context '"Entity2"' started tracking '"SomeDbContext"' entity. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see key values.
// Repeated for every row in Entity2 table

// And so on through every DbSet

I suspect we have some sort of mis-config somewhere. This happens super sporadically, so I suspect we have some mis-config/data issue as every query and save has been successful thousands of times. It's just some crazy scenario we can't track down

Further technical details

EF Core version: 2.1.3
Database Provider: Microsoft.EntityFrameworkCore.SqlServer
Operating system: Windows Server 2016
IDE: Visual Studio 2017 15.8