It's very slow, particularly since introducing byte weaving to introduce chaos in concurrency-sensitive places. Presently it takes a single thread in the region

It's very slow, particularly since introducing byte weaving to introduce chaos in concurrency-sensitive places. Presently it takes a single thread in the region of twenty minutes to simulate a cluster from startup to shutdown, and to run a thousand linearisable operations (down from a couple of minutes prior to those changes). I haven't got any numbers on the rate of context switches per second, but it is certainly a great deal less than 2.5M/s. This kind of approach is in my opinion a _requirement_ for work on distributed consensus protocols, which the Cassandra community is improving at the moment: the upcoming 4.1 release has some major improvements to its Paxos implementation that were validated by this simulation, and the following release is expected to contain a novel distributed consensus protocol we have named Accord, for supporting multi-key transactions. So, I'm not sure it has affected the speed or ease of shipping improvements, rather than enabled a class of work that would have previously been impossible to do safely (IMO).