SkyStore: Cost-Optimized Object Storage Across Regions and Clouds.

Michael Factor IBM Thomas J. Watson Research Center, Yorktown Heights, USA http://researchweb.watson.ibm.com/people/f/factor/ https://dl.acm.org/profile/81100211658

Shu Liu Xiangxi Mo Moshik Hershcovitch Henric Zhang Audrey Cheng Guy Girmonsky Gil Vernik Michael Factor Tiemo Bang Soujanya Ponnapalli Natacha Crooks Joseph Gonzalez 0001 Danny Harnik Ion Stoica SkyStore: Cost-Optimized Object Storage Across Regions and Clouds. 2084-2096 2025 March 18 Proc. VLDB Endow. 7 https://www.vldb.org/pvldb/vol18/p2084-liu.pdf https://doi.org/10.14778/3734839.3734846 db/journals/pvldb/pvldb18.html#LiuMHZCGVFBPCGHS25 streams/journals/pvldb

Shu Liu Xiangxi Mo Moshik Hershcovitch Henric Zhang Audrey Cheng Guy Girmonsky Gil Vernik Michael Factor Tiemo Bang Soujanya Ponnapalli Natacha Crooks Joseph E. Gonzalez Danny Harnik Ion Stoica SkyStore: Cost-Optimized Object Storage Across Regions and Clouds. 2025 February abs/2502.20818 CoRR https://doi.org/10.48550/arXiv.2502.20818 db/journals/corr/corr2502.html#abs-2502-20818 streams/journals/corr

Matan Orbach Ohad Eytan Benjamin Sznajder Ariel Gera Odellia Boni Yoav Kantor Gal Bloch Omri Levy Hadas Abraham Nitzan Barzilay Eyal Shnarch Michael Factor Shila Ofek-Koifman Paula Ta-Shma Assaf Toledo An Analysis of Hyper-Parameter Optimization Methods for Retrieval Augmented Generation. 2025 May abs/2505.03452 CoRR https://doi.org/10.48550/arXiv.2505.03452 db/journals/corr/corr2505.html#abs-2505-03452 streams/journals/corr

Ronen I. Kat Doron Chen Michael Factor Chris Giblin Avi Ziv Aleksander Slominski Hybrid Cloud Connector: Offloading integration complexities. 196-197 2024 SYSTOR https://doi.org/10.1145/3688351.3689168 conf/systor/2024 db/conf/systor/systor2024.html#KatCFGZS24 Doron Chen Michael Factor Danny Harnik Ronen I. Kat Eliad Tsfadia Length preserving compression: marrying encryption with compression. 15:1-15:12 2021 SYSTOR https://doi.org/10.1145/3456727.3463780 https://www.wikidata.org/entity/Q130849299 conf/systor/2021 db/conf/systor/systor2021.html#ChenFHKT21 Eitan Rosenfeld Aviad Zuck Nadav Amit Michael Factor Dan Tsafrir RAIDP: replication with intra-disk parity. 26:1-26:17 2020 EuroSys https://doi.org/10.1145/3342195.3387546 conf/eurosys/2020 db/conf/eurosys/eurosys2020.html#RosenfeldZAFT20 Gil Vernik Michael Factor Elliot K. Kolodner Pietro Michiardi Effi Ofer Francesco Pace Stocator: Providing High Performance and Fault Tolerance for Apache Spark Over Object Storage. 462-471 2018 CCGrid https://doi.org/10.1109/CCGRID.2018.00073 https://doi.ieeecomputersociety.org/10.1109/CCGRID.2018.00073 https://www.wikidata.org/entity/Q131114737 conf/ccgrid/2018 db/conf/ccgrid/ccgrid2018.html#VernikFKMOP18 Artem Barger Yacov Manevich Vita Bortnikov Yoav Tock Michael Factor Michal Malka Shared Cloud Object Store, governed by permissioned blockchain. 114 2018 SYSTOR https://doi.org/10.1145/3211890.3211915 https://www.wikidata.org/entity/Q111687989 conf/systor/2018 db/conf/systor/systor2018.html#BargerMBTFM18 Gil Vernik Michael Factor Elliot K. Kolodner Effi Ofer Pietro Michiardi Francesco Pace Stocator: an object store aware connector for apache spark. 653 2017 SoCC https://doi.org/10.1145/3127479.3134761 https://www.wikidata.org/entity/Q131114741 conf/cloud/2017 db/conf/cloud/socc2017.html#VernikFKOMP17 Gil Vernik Michael Factor Elliot K. Kolodner Effi Ofer Pietro Michiardi Francesco Pace Stocator: a high performance object store connector for spark. 27:1 2017 SYSTOR https://doi.org/10.1145/3078468.3078496 https://www.wikidata.org/entity/Q131114725 conf/systor/2017 db/conf/systor/systor2017.html#VernikFKOMP17

Gil Vernik Michael Factor Elliot K. Kolodner Pietro Michiardi Effi Ofer Francesco Pace Stocator: A High Performance Object Store Connector for Spark. 2017 abs/1709.01812 CoRR http://arxiv.org/abs/1709.01812 db/journals/corr/corr1709.html#abs-1709-01812

Yonatan Gottesman Joel Nider Ronen I. Kat Yaron Weinsberg Michael Factor Using Storage Class Memory Efficiently for an In-memory Database. 21:1 2016 SYSTOR https://doi.org/10.1145/2928275.2933273 https://www.wikidata.org/entity/Q130853479 conf/systor/2016 db/conf/systor/systor2016.html#GottesmanNKWF16 Michael Factor David Hadas Aner Hamama Nadav Har'El Elliot K. Kolodner Anil Kurmus Alexandra Shulman-Peleg Alessandro Sorniotti Secure Logical Isolation for Multi-tenancy in cloud storage. 1-5 2013 MSST https://doi.org/10.1109/MSST.2013.6558424 https://doi.ieeecomputersociety.org/10.1109/MSST.2013.6558424 conf/mss/2013 db/conf/mss/msst2013.html#FactorHHHKKSS13 Gala Yadgar Michael Factor Assaf Schuster Cooperative caching with return on investment. 1-13 2013 MSST https://doi.org/10.1109/MSST.2013.6558446 https://doi.ieeecomputersociety.org/10.1109/MSST.2013.6558446 conf/mss/2013 db/conf/mss/msst2013.html#YadgarFS13 Muli Ben-Yehuda Michael Factor Eran Rom Avishay Traeger Eran Borovik Ben-Ami Yassour Adding advanced storage controller functionality via low-overhead virtualization. 15 2012 FAST https://www.usenix.org/conference/fast12/adding-advanced-storage-controller-functionality-low-overhead-virtualization conf/fast/2012 db/conf/fast/fast2012.html#Ben-YehudaFRTBY12

Erik Elmroth Michael Factor Ethan L. Miller Margo I. Seltzer Is the Future of Preservation Cloudy? (Dagstuhl Seminar 12472). 102-134 2012 2 Dagstuhl Reports 11 https://doi.org/10.4230/DagRep.2.11.102 db/journals/dagstuhl-reports/dagstuhl-reports2.html#ElmrothFMS12

Gala Yadgar Michael Factor Kai Li 0001 Assaf Schuster Management of Multilevel, Multiclient Cache Hierarchies with Application Hints. 5:1-5:51 2011 29 ACM Trans. Comput. Syst. 2 https://doi.org/10.1145/1963559.1963561 db/journals/tocs/tocs29.html#YadgarFLS11

Orit Edelstein Philip Taylor Eliot E. Salant Thomas Risse 0001 Ross King Michael Factor Evolving Domains, Problems and Solutions for Long Term Digital Preservation. 2011 iPRES https://hdl.handle.net/11353/10.294246 conf/ipres/2011 db/conf/ipres/ipres2011.html#EdelsteinTSRKF11 Muli Ben-Yehuda Michael D. Day Zvi Dubitzky Michael Factor Nadav Har'El Abel Gordon Anthony Liguori Orit Wasserman Ben-Ami Yassour The Turtles Project: Design and Implementation of Nested Virtualization. 423-436 2010 OSDI http://www.usenix.org/events/osdi10/tech/full_papers/Ben-Yehuda.pdf conf/osdi/2010 db/conf/osdi/osdi2010.html#Ben-YehudaDDFHGLWY10 Mohammed G. Khatib Xubin He Michael Factor IEEE 26th Symposium on Mass Storage Systems and Technologies, MSST 2012, Lake Tahoe, Nevada, USA, May 3-7, 2010 IEEE Computer Society 2010 MSST 978-1-4244-7153-9 https://ieeexplore.ieee.org/xpl/conhome/5488875/proceeding http://www.computer.org/csdl/proceedings/msst/2010/7152/00/index.html db/conf/mss/msst2010.html Michael Factor Ealan Henis Dalit Naor Simona Rabinovici-Cohen Petra Reshef Shahar Ronen Giovanni Michetti Maria Guercio Authenticity and Provenance in Long Term Digital Preservation: Modeling and Implementation in Preservation Aware Storage. 2009 Workshop on the Theory and Practice of Provenance http://www.usenix.org/events/tapp09/tech/full_papers/factor/factor.pdf conf/fast/2009tapp db/conf/fast/tapp2009.html#FactorHNRRRMG09 Muli Ben-Yehuda David Breitgand Michael Factor Hillel Kolodner Valentin Kravtsov Dan Pelleg NAP: a building block for remediating performance bottlenecks via black box network analysis. 179-188 2009 ICAC https://doi.org/10.1145/1555228.1555270 conf/icac/2009 db/conf/icac/icac2009.html#Ben-YehudaBFKKP09 Michael Factor Assaf Schuster Konstantin Shagin Tal Zamir Optimistic concurrency for clusters via speculative locking. 1 2009 SYSTOR https://doi.org/10.1145/1534530.1534532 conf/systor/2009 db/conf/systor/systor2009.html#FactorSSZ09 Miriam Allalouf Yuriy Arbitman Michael Factor Ronen I. Kat Kalman Z. Meth Dalit Naor Storage modeling for power estimation. 3 2009 SYSTOR https://doi.org/10.1145/1534530.1534535 conf/systor/2009 db/conf/systor/systor2009.html#AllaloufAFKMN09 Miriam Allalouf Michael Factor Dror G. Feitelson Proceedings of of SYSTOR 2009: The Israeli Experimental Systems Conference 2009, Haifa, Israel, May 4-6, 2009 SYSTOR ACM 2009 db/conf/systor/systor2009.html 978-1-60558-623-6 ACM International Conference Proceeding Series

Simona Rabinovici-Cohen Michael Factor Dalit Naor Leeat Ramati Petra Reshef Shahar Ronen Julian Satran David L. Giaretta Preservation DataStores: New storage paradigm for preservation environments. 389-400 2008 52 IBM J. Res. Dev. 4-5 https://doi.org/10.1147/rd.524.0389 db/journals/ibmrd/ibmrd52.html#Rabinovici-CohenFNRRRSG08

David Nagle Michael Factor Sami Iren Dalit Naor Erik Riedel Ohad Rodeh Julian Satran The ANSI T10 object-based storage standard and current implementations. 401-412 2008 52 IBM J. Res. Dev. 4-5 https://doi.org/10.1147/rd.524.0401 db/journals/ibmrd/ibmrd52.html#NagleFINRRS08

Paula Ta-Shma Guy Laden Muli Ben-Yehuda Michael Factor Virtual machine time travel using continuous data protection and checkpointing. 127-134 2008 42 ACM SIGOPS Oper. Syst. Rev. 1 https://doi.org/10.1145/1341312.1341341 db/journals/sigops/sigops42.html#Ta-ShmaLBF08

Gala Yadgar Michael Factor Kai Li 0001 Assaf Schuster MC2: Multiple Clients on a Multilevel Cache. 722-730 2008 ICDCS https://doi.org/10.1109/ICDCS.2008.29 https://doi.ieeecomputersociety.org/10.1109/ICDCS.2008.29 conf/icdcs/2008 db/conf/icdcs/icdcs2008.html#YadgarFLS08

Michael Factor Dalit Naor Simona Rabinovici-Cohen Leeat Ramati Petra Reshef Julian Satran The need for preservation aware storage: a position paper. 19-23 2007 41 ACM SIGOPS Oper. Syst. Rev. 1 https://doi.org/10.1145/1228291.1228298 db/journals/sigops/sigops41.html#FactorNRRRS07

Guy Laden Paula Ta-Shma Eitan Yaffe Michael Factor Shachar Fienblit Architectures for Controller Based CDP. 107-121 2007 FAST http://www.usenix.org/events/fast07/tech/laden.html conf/fast/2007 db/conf/fast/fast2007.html#LadenTYFF07 Gala Yadgar Michael Factor Assaf Schuster Karma: Know-It-All Replacement for a Multilevel Cache. 169-184 2007 FAST http://www.usenix.org/events/fast07/tech/yadgar.html conf/fast/2007 db/conf/fast/fast2007.html#YadgarFS07 Michael Factor Dalit Naor Simona Rabinovici-Cohen Leeat Ramati Petra Reshef Julian Satran David L. Giaretta Preservation DataStores: Architecture for Preservation Aware Storage. 3-15 2007 conf/mss/2007 MSST https://doi.ieeecomputersociety.org/10.1109/MSST.2007.27 db/conf/mss/msst2007.html#FactorNRRRSG07 Michael Factor Dalit Naor Eran Rom Julian Satran Sivan Tal Capability based Secure Access Control to Networked Storage Devices. 114-128 2007 conf/mss/2007 MSST https://doi.ieeecomputersociety.org/10.1109/MSST.2007.6 db/conf/mss/msst2007.html#FactorNRST07 Michael Factor Konstantin Shagin Assaf Schuster A Transparent Distributed Runtime for Java. 2007 Handbook of Parallel Computing https://doi.org/10.1201/9781420011296.ch42 reference/crc/2007pc db/reference/crc/pc2007.html#FactorSS07

Michael Factor Assaf Schuster Konstantin Shagin A Platform-Independent Distributed Runtime for Standard Multithreaded Java. 113-142 2006 34 Int. J. Parallel Program. 2 https://doi.org/10.1007/s10766-006-0007-0 db/journals/ijpp/ijpp34.html#FactorSS06

Michael Factor David Nagle Dalit Naor Erik Riedel Julian Satran The OSD Security Protocol. 29-39 2005 IEEE Security in Storage Workshop https://doi.org/10.1109/SISW.2005.12 https://doi.ieeecomputersociety.org/10.1109/SISW.2005.12 conf/sisw/2005 db/conf/sisw/sisw2005.html#FactorNNRS05 Michael Factor Assaf Schuster Konstantin Shagin A Distributed Runtime for Java: Yesterday and Today. 2004 conf/ipps/2004 IPDPS https://doi.org/10.1109/IPDPS.2004.1303149 https://doi.ieeecomputersociety.org/10.1109/IPDPS.2004.1303149 db/conf/ipps/ipdps2004-w5.html#FactorSS04 Michael Factor Assaf Schuster Konstantin Shagin Instrumentation of standard libraries in object-oriented languages: the twin class hierarchy approach. 288-300 2004 conf/oopsla/2004p OOPSLA https://doi.org/10.1145/1028976.1029000 https://doi.org/10.1145/1035292.1029000 https://www.wikidata.org/entity/Q130960299 db/conf/oopsla/oopsla2004p.html#FactorSS04

Alain C. Azagury Michael Factor William F. Micka Advanced functions for storage subsystems: Supporting continuous availability. 268-279 2003 42 IBM Syst. J. 2 https://doi.org/10.1147/sj.422.0268 db/journals/ibmsj/ibmsj42.html#AzaguryFM03

Michael Factor Assaf Schuster Konstantin Shagin JavaSplit: A Runtime for Execution of Monolithic Java Programs on Heterogeneous Collections of Commodity Workstations. 110-117 2003 conf/cluster/2003 CLUSTER https://doi.org/10.1109/CLUSTR.2003.1253306 https://doi.ieeecomputersociety.org/10.1109/CLUSTR.2003.1253306 db/conf/cluster/cluster2003.html#FactorSS03 Alain Azagury Vladimir Dreizin Michael Factor Ealan Henis Dalit Naor Noam Rinetzky Ohad Rodeh Julian Satran Ami Tavory Lena Yerushalmi Towards an Object Stor. 165- 2003 conf/mss/2003 IEEE Symposium on Mass Storage Systems https://doi.org/10.1109/MASS.2003.1194853 https://doi.ieeecomputersociety.org/10.1109/MASS.2003.1194853 db/conf/mss/mss2003.html#AzaguryDFHNRRSTY03

Alain Azagury Michael Factor Yoëlle S. Maarek Benny Mandler A novel navigation paradigm for XML repositories. 515-525 2002 53 J. Assoc. Inf. Sci. Technol. 6 db/journals/jasis/jasis53.html#AzaguryFMM02 https://doi.org/10.1002/asi.10062

Mark Silberstein Michael Factor Dean H. Lorenz DYNAMO - DirectorY, Net Archiver and MOver. 256-267 2002 conf/grid/2002 GRID https://doi.org/10.1007/3-540-36133-2_23 db/conf/grid/grid2002.html#SilbersteinFL02 Michael Factor Assaf Schuster Konstantin Shagin Execution of monolithic Java programs on large non-dedicated collections of commodity workstations. 227 2002 conf/java/2002 Java Grande https://doi.org/10.1145/583810.583839 db/conf/java/java2002.html#FactorSS02 Alain Azagury Ran Canetti Michael Factor Shai Halevi Ealan Henis Dalit Naor Noam Rinetzky Ohad Rodeh Julian Satran A Two Layered Approach for Securing an Object Store Network. 10-23 2002 conf/sisw/2002 IEEE Security in Storage Workshop https://doi.org/10.1109/SISW.2002.1183506 https://doi.ieeecomputersociety.org/10.1109/SISW.2002.1183506 db/conf/sisw/sisw2002.html#AzaguryCFHHNRRS02

Yariv Aridor Michael Factor Avi Teperman A distributed implementation of a virtual machine for Java. 221-244 2001 13 Concurr. Comput. Pract. Exp. 3 db/journals/concurrency/concurrency13.html#AridorFT01 https://doi.org/10.1002/cpe.565

Michael Factor Dafna Sheinwald Compression in the presence of shared data. 29-41 2001 135 Inf. Sci. 1-2 db/journals/isci/isci135.html#FactorS01 https://doi.org/10.1016/S0020-0255(01)00099-8

Michael Factor Dafna Sheinwald Ben-Ami Yassour Software Compression in the Client/Server Environment. 233-242 2001 conf/dcc/2001 Data Compression Conference https://doi.org/10.1109/DCC.2001.917154 https://doi.ieeecomputersociety.org/10.1109/DCC.2001.917154 db/conf/dcc/dcc2001.html#FactorSY01 Yariv Aridor Michael Factor Avi Teperman Implementing Java on Clusters. 722-731 2001 conf/europar/2001 Euro-Par https://doi.org/10.1007/3-540-44681-8_104 db/conf/europar/europar2001.html#AridorFT01

Yariv Aridor Michael Factor Avi Teperman Tamar Eilam Assaf Schuster Transparently Obtaining Scalability for Java Applications on a Cluster. 1159-1193 2000 60 J. Parallel Distributed Comput. 10 https://doi.org/10.1006/jpdc.2000.1649 db/journals/jpdc/jpdc60.html#AridorFTES00

Yariv Aridor Michael Factor Avi Teperman Tamar Eilam Assaf Schuster A high performance cluster JVM presenting a pure single system image. 168-177 2000 conf/java/2000 Java Grande https://doi.org/10.1145/337449.337543 db/conf/java/java2000.html#AridorFTES00 Yariv Aridor Michael Factor Avi Teperman cJVM: A Single System Image of a JVM on a Cluster. 4-11 1999 conf/icpp/1999 ICPP https://doi.org/10.1109/ICPP.1999.797382 https://doi.ieeecomputersociety.org/10.1109/ICPP.1999.797382 db/conf/icpp/icpp1999.html#AridorFT99

Michael Factor David Gelernter Craig E. Kolb Perry L. Miller Dean F. Sittig Real-Time Data Fusion in the Intensive Care Unit. 45-54 1991 24 Computer 11 db/journals/computer/computer24.html#FactorGKMS91 https://doi.org/10.1109/2.116850 http://doi.ieeecomputersociety.org/10.1109/2.116850

Michael Factor A Formal Specification of the Process Trellis. 277-294 1991 conf/parle/1991-2 PARLE (2) db/conf/parle/parle91-2.html#Factor91 https://doi.org/10.1007/3-540-54152-7_70 Michael Factor The Process Trellis Architectur for Real-Time Monitors. 147-155 1990 conf/ppopp/1990 PPoPP db/conf/ppopp/ppopp90.html#Factor90 https://doi.org/10.1145/99163.99180 https://doi.org/10.1145/99164.99180 Michael Factor David Gelernter The process trellis: a software architecture for intelligent monitors. 174-181 1989 TAI https://doi.org/10.1109/TAI.1989.65318 https://doi.ieeecomputersociety.org/10.1109/TAI.1989.65318 conf/ictai/1989 db/conf/ictai/ictai1989.html#FactorG89 Hadas Abraham Miriam Allalouf Nadav Amit Yuriy Arbitman Yariv Aridor Alain Azagury Alain C. Azagury Tiemo Bang Artem Barger Nitzan Barzilay Muli Ben-Yehuda Gal Bloch Odellia Boni Eran Borovik Vita Bortnikov David Breitgand Ran Canetti Doron Chen Audrey Cheng Natacha Crooks Michael D. Day Vladimir Dreizin Zvi Dubitzky Orit Edelstein Tamar Eilam Erik Elmroth Ohad Eytan Dror G. Feitelson Shachar Fienblit David Gelernter Ariel Gera David L. Giaretta Chris Giblin Guy Girmonsky Joseph Gonzalez 0001Joseph E. Gonzalez Abel Gordon Yonatan Gottesman Maria Guercio David Hadas Shai Halevi Aner Hamama Nadav Har'El Danny Harnik Xubin He Ealan A. HenisEalan Henis Moshe HershcovitchMoshik Hershcovitch Sami Iren Yoav Kantor Ronen I. Kat Mohammed G. Khatib Ross King Craig E. Kolb Elliot K. Kolodner Hillel Kolodner Valentin Kravtsov Anil Kurmus Guy Laden Omri Levy Kai Li 0001 Anthony Liguori Shu Liu Dean H. Lorenz Yoelle MaarekYoëlle S. Maarek Michal Malka Benny Mandler Yacov Manevich Kalman Z. Meth Giovanni Michetti Pietro Michiardi William F. Micka Ethan L. Miller Perry L. Miller Xiangxi Mo David Nagle Dalit Naor Joel Nider Shila Ofek-Koifman Effi Ofer Matan Orbach Francesco Pace Dan Pelleg Soujanya Ponnapalli Simona Rabinovici-Cohen Leeat Ramati Petra Reshef Erik Riedel Noam Rinetzky Thomas Risse 0001 Ohad Rodeh Eran Rom Shahar Ronen Eitan Rosenfeld Eliot E. Salant Julian Satran Assaf Schuster Margo I. Seltzer Konstantin Shagin Dafna Sheinwald Eyal Shnarch Alexandra Shulman-Peleg Mark Silberstein Dean F. Sittig Aleksander Slominski Alessandro Sorniotti Ion Stoica Benjamin Sznajder Paula Ta-Shma Sivan Tal Ami Tavory Philip Taylor Avi Teperman Yoav Tock Assaf Toledo Avishay Traeger Dan Tsafrir Eliad Tsfadia Gil Vernik Orit Wasserman Yaron Weinsberg Gala Yadgar Eitan Yaffe Ben-Ami Yassour Lena Yerushalmi Tal Zamir Henric Zhang Avi Ziv Aviad Zuck