Publications by Moritz Hoffmann
2019
Proceedings of the VLDB 2019, Los Angeles, CA, USA, August 2019
We design and implement Megaphone, a data migration mechanism
for stateful distributed dataflow engines with latency objectives.
When compared to existing migration mechanisms, Megaphone has
the following differentiating characteristics: (i) migrations can be
subdivided to a configurable granularity to avoid latency spikes, and
(ii) migrations can be prepared ahead of time to avoid runtime coordination.
Megaphone is implemented as a library on an unmodified
timely dataflow implementation, and provides an operator interface
compatible with its existing APIs.We evaluate Megaphone on established
benchmarks with varying amounts of state and observe that
compared to naïve approaches Megaphone reduces service latencies
during reconfiguration by orders of magnitude without significantly
increasing steady-state overhead.
@inproceedings{abc, abstract = {We design and implement Megaphone, a data migration mechanism for stateful distributed dataflow engines with latency objectives. When compared to existing migration mechanisms, Megaphone has the following differentiating characteristics: (i) migrations can be subdivided to a configurable granularity to avoid latency spikes, and (ii) migrations can be prepared ahead of time to avoid runtime coordination. Megaphone is implemented as a library on an unmodified timely dataflow implementation, and provides an operator interface compatible with its existing APIs.We evaluate Megaphone on established benchmarks with varying amounts of state and observe that compared to na{\"\i}ve approaches Megaphone reduces service latencies during reconfiguration by orders of magnitude without significantly increasing steady-state overhead.}, author = {Moritz Hoffmann and Andrea Lattuada and Frank McSherry}, booktitle = {Proceedings of the VLDB 2019}, title = {Megaphone: Latency-conscious state migration for distributed streaming dataflows}, venue = {Los Angeles, CA, USA}, year = {2019} }
2017
Proceedings of the 16th Workshop on Hot Topics in Operating Systems, Whistler, BC, Canada, May 2017
It is time to reconsider memory protection. The emergence of large non-volatile main memories, scalable interconnects, and rack-scale computers running large numbers of small "micro services" creates significant challenges for memory protection based solely on MMU mechanisms. Central to this is a tension between protection and translation: optimizing for translation performance often comes with a cost in protection flexibility.
We argue that a key-based memory protection scheme, complementary to but separate from regular page-level translation, is a better match for this new world. We present MaKC, a new architecture which combines two levels of capability-based protection to scale fine-grained memory protection at both user and kernel level to large numbers of protection domains without compromising efficiency at scale or ease of revocation.
@inproceedings{abc, abstract = {It is time to reconsider memory protection. The emergence of large non-volatile main memories, scalable interconnects, and rack-scale computers running large numbers of small "micro services" creates significant challenges for memory protection based solely on MMU mechanisms. Central to this is a tension between protection and translation: optimizing for translation performance often comes with a cost in protection flexibility. We argue that a key-based memory protection scheme, complementary to but separate from regular page-level translation, is a better match for this new world. We present MaKC, a new architecture which combines two levels of capability-based protection to scale fine-grained memory protection at both user and kernel level to large numbers of protection domains without compromising efficiency at scale or ease of revocation.}, author = {Reto Achermann and Chris Dalton and Paolo Faraboschi and Moritz Hoffmann and Dejan S. Milojicic and Geoffrey Ndu and Alexander Richardson and Timothy Roscoe and Adrian L. Shaw and Robert N. M. Watson}, booktitle = {Proceedings of the 16th Workshop on Hot Topics in Operating Systems}, title = {Separating Translation from Protection in Address Spaces with Dynamic Remapping}, venue = {Whistler, BC, Canada}, year = {2017} }
2016
12th USENIX Symposium on Operating Systems Design and Implementation, OSDI 2016, Savannah, GA, USA, November 2016
@inproceedings{abc, author = {Stefan Kaestle and Reto Achermann and Roni Haecki and Moritz Hoffmann and Sabela Ramos and Timothy Roscoe}, booktitle = {12th USENIX Symposium on Operating Systems Design and Implementation, OSDI 2016, Savannah, GA, USA}, title = {Machine-Aware Atomic Broadcast Trees for Multicores.}, url = {https://www.usenix.org/conference/osdi16/technical-sessions/presentation/kaestle}, year = {2016} }
2014
Systems Group Master's Thesis, no. 115; Department of Computer Science, September 2014
Supervised by: Prof. Dr. Donald Kossmann
Supervised by: Prof. Dr. Donald Kossmann
@mastersthesis{abc, author = {Moritz Hoffmann}, school = {115}, title = {Completeness is in the eye of the beholder: A sandbox concept for databases}, year = {2014} }