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To summarize again, Aeolus is based on a problem that doesn't actually exist, its evaluation is inadequate, and it seems likely that the resulting protocol is not competitive.
Author’s Response
One of the Aeolus authors has posted a response to this critique, titled “Severe Loss is not Rare in High speed Datacenter Networks”. This document presents various arguments why packet losses might occur in datacenter networks. I don’t disagree with the issues raised in the document. However, the document makes strong claims such as “Severe packet loss under incast-like traffic is not rare” without providing any data to justify the claims. I followed up with the author to ask if he had any supporting data, and he replied that he did not. The response argues that it will eventually become necessary for all transport protocols to deal with packet loss under incast. I agree that this could happen if link speeds continue to increase faster than switch buffer capacity. But even if this does happen I doubt that Aeolus is the right solution because it penalizes short messages; better to drop packets from the longest messages, where occasional retransmissions will have the smallest effect on performance. In any case, more work is needed in this area, both to understand the degree of the buffer problem and to explore possible solutions.