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New Project Grant

PANDAS: Programmable Appliance for Near Data Processing Accelerated Storage

BMBF KMU-Innovativ

Principle Investigators:
PRO DESIGN Electronic GmbH
Xelera Technologies GmbH
Embedded Systems and Applications Group, Technische Universitaet Darmstadt
Data Management Lab, Reutlingen University

Abstract:

...comming soon.

Efficient Data and Indexing Structure for Blockchains in Enterprise Systems

C. Riegger, T. Vincon, I. Petrov.
In Proc. iiWAS 2018

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17.09.2018 Paper Accepted at iiWAS 2017

C. Riegger, T. Vincon, I. Petrov. Efficient Data and Indexing Structure for Blockchains in Enterprise Systems. In Proc. iiWAS 2018.

[Extended Abstract]

Abstract:

Blockchains yield to new workloads in database management systems and K/V-Stores. Distributed Ledger Technology (DLT) is a technique for managing transactions in ’trustless’ distributed systems. Yet, clients of nodes in blockchain networks are backed by ’trustworthy’ K/V-Stores, like LevelDB or RocksDB in Ethereum, which are based on Log-Structured Merge Trees (LSM-Trees). However, LSM-Trees do not fully match the properties of blockchains and enterprise workloads. In this paper, we claim that Partitioned B-Trees (PBT) fit the proper- ties of this DLT: uniformly distributed hash keys, immutability, consensus, invalid blocks, unspent and off-chain transactions, reorganization and data state / version ordering in a distributed log-structure. PBT can locate records of newly inserted key-value pairs, as well as data of unspent transactions, in separate partitions in main memory. Once several blocks acquire consensus, PBTs evict a whole partition, which becomes immutable, to sec- ondary storage. This behavior minimizes write amplification and enables a beneficial sequential write pattern on modern hardware. Furthermore, DLT implicate some type of log-based versioning. PBTs can serve as MV-Store for data storage of logical blocks and indexing in multi-version concurrency control (MVCC) transaction processing.

Two entries in Encyclopedia of Big Data Technologies, Sakr, Sherif, Zomaya, Albert (Eds.), Springer

I. Petrov, T. Vincon, A. Koch, J. Oppermann, S. Hardock, C. Riegger. Active Storage
In Enc. Big Data Technologies Sakr, Zomaya (Eds.) Springer 2018.

I. Petrov, A. Koch, T. Vincon, S. Hardock, C. Riegger. Transaction Processing on NVM
In Enc. Big Data Technologies Sakr, Zomaya (Eds.) Springer 2018.

NoFTL-KV: Tackling Write-Amplification on KV-Stores with Native Storage Management

T. Vincon, S. Hardock C. Riegger, J. Oppermann, A. Koch, I. Petrov.
In Proc. EDBT 2018

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22.12.2017 Paper Accepted at EDBT 2018

T. Vincon, S. Hardock C. Riegger, J. Oppermann, A. Koch, I. Petrov. NoFTL-KV: Tackling Write-Amplification on KV-Stores with Native Storage Management. In Proc. EDBT 2018.

[PDF]

Abstract:

Modern persistent Key/Value stores are designed to meet the demand for high transactional throughput and high data-ingestion rates. Still, they rely on backwards-compatible storage stack and abstractions to ease space management, foster seamless proliferation and system integration. Their dependence on the traditional I/O stack has negative impact on performance, causes unacceptably high write-amplification, and limits the storage longevity.
In the present paper we present NoFTL-KV, an approach that results in a lean I/O stack, integrating physical storage management natively in the Key/Value store. NoFTL-KV eliminates backwards compatibility, allowing the Key/Value store to directly consume the characteristics of modern storage technologies. NoFTL-KV is implemented under RocksDB. The performance evaluation under LinkBench shows that NoFTL-KV improves transactional throughput by 33%, while response times improve up to 2.3x. Furthermore, NoFTL-KV reduces write-amplification 19x and improves storage longevity by imately the same factor.

Multi-Version Indexing and modern Hardware Technologies

A Survey of present Indexing Approaches

C. Riegger, T. Vincon, I. Petrov.
In Proc. iiWAS 2017

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02.10.2017 Paper Accepted at iiWAS 2017

C. Riegger, T. Vincon, I. Petrov. Multi-Version Indexing and modern Hardware Technologies - A Survey of present Indexing Approaches. In Proc. iiWAS 2017.

[PDF]

Abstract:

Characteristics of modern computing and storage technologies fundamentally differ from traditional hardware. There is a need to optimally leverage their performance, endurance and energy consumption characteristics. Therefore, existing architectures and algorithms in modern high performance database management systems have to be redesigned and advanced. Multi Version Concurrency Control (MVCC) approaches in data-base management systems maintain multiple physically independent tuple versions. Snapshot isolation approaches enable high parallelism and concurrency in workloads with almost serializable consistency level. Modern hardware technologies benefit from multi-version approaches. Indexing multi-version data on modern hardware is still an open research area. In this paper, we provide a survey of popular multi-version indexing approaches and an extended scope of high performance single-version approaches. An optimal multi-version index structure brings look-up efficiency of tuple versions, which are visible to transactions, and effort on index maintenance in balance for different workloads on modern hardware technologies.

Write-Optimized Indexing with Partitioned B-Trees

C. Riegger, T. Vincon, I. Petrov.
In Proc. iiWAS 2017

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02.10.2017 Paper Accepted at iiWAS 2017

C. Riegger, T. Vincon, I. Petrov. Write-Optimized Indexing with Partitioned B-Trees. In Proc. iiWAS 2017.

[PDF]

Abstract:

Database management systems (DBMS) are critical performance component in large scale applications under modern update-intensive workloads. Additional access paths accelerate look-up performance in DBMS for frequently queried attributes, but the required maintenance slows down update performance. The ubiquitous B + -Tree is a commonly used key-indexed access path that is able to support many required functionalities with logarithmic access time to requested records. Modern processing and storage technologies and their characteristics require reconsideration of matured indexing approaches for today’s workloads. Partitioned B-Trees (PBT) leverage characteristics of modern hardware technologies and complex memory hierarchies as well as high update rates and changes in workloads by maintaining partitions within one single B + -Tree. This paper includes an experimental evaluation of PBTs optimized write pattern and performance improvements. With PBT transactional throughput under TPC-C increases 30%; PBT results in beneficial sequential write patterns even in presence of updates and maintenance operations.