Background

Today DAOS is designed support multi-tenancy, QoS is an important feature to guarantee fairness of service for tenants. However, today DAOS has no QoS framework and , it simply uses FIFO as I/O requests queue, which can neither guarantee fairness nor support request priority. In addition, the DAOS client has no mechanism to throttle RPC sending. A malicious application (or a legitimate application at large scale) can start hundreds of processes and send millions of RPCs to a server, which will consume significant resources on the server. The DAOS engine has no throttling on RPC receiving either, so an engine may underperform or even be killed by the OOM killer because it can indefinitely allocate resources for incoming I/O requests, unable to keep up with processing those requests.

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