TY - GEN A1 - Kolbeck, Björn A1 - Högqvist, Mikael A1 - Stender, Jan A1 - Hupfeld, Felix T1 - Fault-Tolerant and Decentralized Lease Coordination in Distributed Systems N2 - Applications which need exclusive access to a shared resource in distributed systems require a fault-tolerant and scalable mechanism to coordinate this exclusive access. Examples of such applications include distributed file systems and master/slave data replication. We present Flease, an algorithm for decentralized and fault-tolerant lease coordination in distributed systems. Our algorithm allows the processes competing for a resource to coordinate exclusive access through leases among themselves without a central component. The resulting system easily scales with an increasing number of nodes and resources. We prove that Flease ensures exclusive access, i.e. guarantees that there is at most one valid lease at any time. T3 - ZIB-Report - 10-02 Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-11658 SN - 1438-0064 ER - TY - GEN A1 - Moser, Monika A1 - Haridi, Seif A1 - Shafaat, Tallat A1 - Schütt, Thorsten A1 - Högqvist, Mikael A1 - Reinefeld, Alexander T1 - Transactional DHT Algorithms N2 - We present a framework for transactional data access on data stored in a DHT. It allows to atomically read and write items and to run distributed transactions consisting of a sequence of read and write operations on the items. Items are symmetrically replicated in order to achieve durability of data stored in the SON. To provide availability of items despite the unavailability of some replicas, operations on items are quorum-based. They make progress as long as a majority of replicas can be accessed. Our framework processes transactions optimistically with an atomic commit protocol that is based on Paxos atomic commit. We present algorithms for the whole framework with an event based notation. Additionally we discuss the problem of lookup inconsistencies and its implications on the one-copy serializability property of the transaction processing in our framework. T3 - ZIB-Report - 09-34 KW - Distributed System KW - DHT KW - Paxos KW - Algorithms KW - Storage Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-11532 SN - 1438-0064 ER - TY - JOUR A1 - Enke, Harry A1 - Steinmetz, Matthias A1 - Adorf, Hans-Martin A1 - Beck-Ratzka, Alexander A1 - Breitling, Frank A1 - Brüsemeister, Thomas A1 - Carlson, Arthur A1 - Ensslin, Torsten A1 - Högqvist, Mikael A1 - Nickelt, Iliya A1 - Radke, Thomas A1 - Reinefeld, Alexander A1 - Reiser, Angelika A1 - Scholl, Tobias A1 - Spurzem, Rainer A1 - Steinacker, Jürgen A1 - Voges, Wolfgang A1 - Wambsganß, Joachim A1 - White, Steve T1 - AstroGrid-D: Grid technology for astronomical science JF - New Astronomy Y1 - 2011 UR - http://www.sciencedirect.com/science/article/pii/S1384107610000837 U6 - https://doi.org/10.1016/j.newast.2010.07.005 VL - 16 IS - 2 SP - 79 EP - 93 ER - TY - JOUR A1 - Kolbeck, Björn A1 - Högqvist, Mikael A1 - Stender, Jan A1 - Hupfeld, Felix T1 - Flease - Lease Coordination Without a Lock Server JF - Parallel and Distributed Processing Symposium, International Y1 - 2011 U6 - https://doi.org/10.1109/IPDPS.2011.94 VL - 0 SP - 978 EP - 988 PB - IEEE Computer Society CY - Los Alamitos, CA, USA ER - TY - CHAP A1 - Stender, Jan A1 - Högqvist, Mikael A1 - Kolbeck, Björn T1 - Loosely Time-Synchronized Snapshots in Object-Based File Systems T2 - Proceedings of the 29th IEEE International Performance, Computing, and Communications Conference Y1 - 2010 U6 - https://doi.org/10.1109/PCCC.2010.5682311 PB - IEEE Computer Society ER - TY - CHAP A1 - Schäfer, Patrick A1 - Högqvist, Mikael T1 - SFA : a symbolic fourier approximation and index for similarity search in high dimensional datasets T2 - Proceedings of the 15th International Conference on Extending Database Technology Y1 - 2012 UR - http://doi.acm.org/10.1145/2247596.2247656 U6 - https://doi.org/10.1145/2247596.2247656 SP - 516 EP - 527 PB - ACM CY - New York, NY, USA ER - TY - JOUR A1 - Kruber, Nico A1 - Högqvist, Mikael A1 - Schütt, Thorsten T1 - The Benefits of Estimated Global Information in DHT Load Balancing JF - Cluster Computing and the Grid, IEEE International Symposium on Y1 - 2011 U6 - https://doi.org/10.1109/CCGrid.2011.11 VL - 0 SP - 382 EP - 391 PB - IEEE Computer Society CY - Los Alamitos, CA, USA ER - TY - CHAP A1 - Stender, Jan A1 - Kolbeck, Björn A1 - Högqvist, Mikael A1 - Hupfeld, Felix T1 - BabuDB: Fast and Efficient File System Metadata Storage T2 - Storage Network Architecture and Parallel I/Os, IEEE International Workshop on Y1 - 2010 U6 - https://doi.org/10.1109/SNAPI.2010.14 SP - 51 EP - 58 PB - IEEE Computer Society CY - Los Alamitos, CA, USA ER - TY - CHAP A1 - Böse, Joos-Hendrik A1 - Andrzejak, Artur A1 - Högqvist, Mikael T1 - Beyond online aggregation: Parallel and incremental data mining with online Map-Reduce T2 - Proceedings of the 2010 Workshop on Massive Data Analytics on the Cloud Y1 - 2010 U6 - https://doi.org/10.1145/1779599.1779602 SP - 3:1 EP - 3:6 PB - ACM CY - New York, NY, USA ER - TY - CHAP A1 - Högqvist, Mikael A1 - Plantikow, Stefan T1 - Towards Explicit Data Placement in Scalable Key/Value Stores T2 - Architectures and Languages for Self-Managing Distributed Systems (SelfMan@SASO) Y1 - 2009 ER -