SERVER-70395, SUPPORT-2778. The symptom is that queries are spilling to disk way more than they did in the classic engine. In addition to spilling to disk more frequently, SBE was also much slower than classic when spilling to disk. This combination of factors would cause severe performance degradation across the entire cluster.

We can simulate this by adjusting the memory threshold for spilling between engines.

Result - we can run this scenario in the testing harness against the placeholder algorithm.