Demo Data from SIGIR 2026 / reviewers in the wild / expert
Zsolt István
dblp:50/10703
· DBLP profile ↗
37ranked-venue papers
11as first author
15since 2021 · last 2026
0000-0002-4127-8573ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Systems, architecture and hardware · 16 · 5 first-author · 4 since 2021Databases, data management, data science and information retrieval · 16 · 5 first-author · 9 since 2021Computer networks · 2 · 1 first-author · 1 since 2021
Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.
| Computer architecture, parallel and distributed computing, and storage systems
9 papers |
Reconfigurable computing and FPGAs · 25% Hardware accelerators and domain-specific architectures · 19% Storage systems · 19% | |
| Databases, data mining, and information retrieval
6 papers |
Query processing and optimization · 54% Distributed and cloud data management · 36% Data mining · 7% | |
| Network and information security
2 papers |
Privacy and data protection · 61% Cryptographic protocols and secure computation · 39% | |
| Computer networks
1 paper |
Datacenter networks · 100% |
Topics — the 22 heaviest of 27, each with the papers that count most for it
| Topic | Weight | Papers | Last | Evidence papers |
|---|---|---|---|---|
Reconfigurable computing and FPGAs
FPGA accelerator |
1.2 | 5 | 2019 | I Can't Believe It's Not (Only) Software! Bionic Distributed Storage for Parquet Files · Proc. VLDB Endow. 2019 doppioDB: A Hardware Accelerated Database · SIGMOD Conference 2017 Accelerating Pattern Matching Queries in Hybrid CPU-FPGA Architectures · SIGMOD Conference 2017 |
Query processing and optimization
secure query processing |
0.9 | 1 | 2025 | Demonstration of Reflex: How SMPC Query Execution can be sped up through Efficient and Flexible Intermediate Result Size Trimming · Proc. VLDB Endow. 2025 |
Privacy and data protection › privacy-preserving query processing
oblivious query processing |
0.9 | 1 | 2025 | Demonstration of Reflex: How SMPC Query Execution can be sped up through Efficient and Flexible Intermediate Result Size Trimming · Proc. VLDB Endow. 2025 |
Cryptographic protocols and secure computation
secure multiparty computation |
0.9 | 1 | 2025 | Demonstration of Reflex: How SMPC Query Execution can be sped up through Efficient and Flexible Intermediate Result Size Trimming · Proc. VLDB Endow. 2025 |
Distributed and cloud data management
data shuffling |
0.8 | 1 | 2024 | Zero-sided RDMA: Network-driven Data Shuffling for Disaggregated Heterogeneous Cloud DBMSs · Proc. ACM Manag. Data 2024 |
Datacenter networks
RDMA |
0.8 | 1 | 2024 | Zero-sided RDMA: Network-driven Data Shuffling for Disaggregated Heterogeneous Cloud DBMSs · Proc. ACM Manag. Data 2024 |
Privacy and data protection
policy compliance |
0.5 | 1 | 2021 | Software-Defined Data Protection: Low Overhead Policy Compliance at the Storage Layer is Within Reach! · Proc. VLDB Endow. 2021 |
Storage systems
distributed storage |
0.5 | 2 | 2019 | I Can't Believe It's Not (Only) Software! Bionic Distributed Storage for Parquet Files · Proc. VLDB Endow. 2019 Caribou: Intelligent Distributed Storage · Proc. VLDB Endow. 2017 |
Hardware accelerators and domain-specific architectures › domain-specific accelerator
storage accelerator |
0.4 | 1 | 2019 | I Can't Believe It's Not (Only) Software! Bionic Distributed Storage for Parquet Files · Proc. VLDB Endow. 2019 |
Query processing and optimization
pattern matching query |
0.3 | 1 | 2017 | Accelerating Pattern Matching Queries in Hybrid CPU-FPGA Architectures · SIGMOD Conference 2017 |
Memory systems › processing-in-memory
near-data processing |
0.3 | 1 | 2017 | Caribou: Intelligent Distributed Storage · Proc. VLDB Endow. 2017 |
Memory systems
processing-in-memory |
0.3 | 1 | 2017 | Caribou: Intelligent Distributed Storage · Proc. VLDB Endow. 2017 |
Distributed systems
consensus |
0.2 | 1 | 2016 | Consensus in a Box: Inexpensive Coordination in Hardware · NSDI 2016 |
Query processing and optimization
cardinality estimation |
0.2 | 1 | 2014 | Histograms as a side effect of data movement for big data · SIGMOD Conference 2014 |
Data mining › data reduction › data summarization
histogram construction |
0.2 | 1 | 2014 | Histograms as a side effect of data movement for big data · SIGMOD Conference 2014 |
Distributed and cloud data management
query offloading |
0.2 | 1 | 2014 | Ibex - An Intelligent Storage Engine with Support for Advanced SQL Off-loading · Proc. VLDB Endow. 2014 |
Hardware accelerators and domain-specific architectures › database accelerator
FPGA-based query processing |
0.2 | 1 | 2014 | Ibex - An Intelligent Storage Engine with Support for Advanced SQL Off-loading · Proc. VLDB Endow. 2014 |
Parallel and multicore computing
histogram computation |
0.2 | 1 | 2014 | Histograms as a side effect of data movement for big data · SIGMOD Conference 2014 |
Parallel and multicore computing
dataflow computing |
0.1 | 1 | 2019 | I Can't Believe It's Not (Only) Software! Bionic Distributed Storage for Parquet Files · Proc. VLDB Endow. 2019 |
Query processing and optimization › query execution
hardware-accelerated query processing |
0.1 | 1 | 2017 | doppioDB: A Hardware Accelerated Database · SIGMOD Conference 2017 |
Information retrieval › pattern matching
regular expression matching |
0.1 | 1 | 2017 | doppioDB: A Hardware Accelerated Database · SIGMOD Conference 2017 |
Memory systems
data movement |
0.1 | 1 | 2014 | Histograms as a side effect of data movement for big data · SIGMOD Conference 2014 |
Methods — techniques the papers use, named apart from their topics
programmable switch · 2.3RDMA · 2.3secure multiparty computation · 1.7query planning · 1.7selective column reads · 0.4data deduplication · 0.4hardware-software hybrid · 0.4FPGA prototyping · 0.4FPGA · 0.4
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Efficient Parquet Parsing on FPGAs
Si Jun Kwon, Zsolt István, Daniel Ritter 0001, Norman May, Christian Färber |
DaMoN | 2 |
| 2026 | How to make Secure Storage fast for DBMSs in Intel SGXv2abstractRecent Trusted Execution Environments based on Intel SGXv2 enable fast and confidential in-memory processing for DBMSs. However, secure persistence remains a major performance and security challenge. While native SGX-based storage mechanisms provide confidentiality and integrity out of the box, they incur high overheads for DBMSs. In this paper, we analyze the overheads and introduce novel techniques for secure and fast DBMS storage. As we show, these techniques reduce the high storage overheads of native SGX storage mechanisms to negligible overheads, enabling practical, high-performance, secure storage for cloud databases. Adrian Lutsch, Christian Franck, Muhammad El-Hindi, Norman May, Zsolt István, Carsten Binnig |
DaMoN | 5 |
| 2025 | Model-Driven Right-Sizing of Offloading in Data Processing PipelinesabstractThe performance of modern Big Data systems used for data processing is often bottlenecked by data movement across various components.Offloading part of the processing closer to the storage and network to reduce this bottleneck is a compelling idea, and in today's hardware landscape, there are many different types of Smart Storage, Smart NIC, or Smart Switch devices one could choose from.One challenge, however, is that it is often unclear at design time what improvements of the end workload one can achieve with a given hardware.Co-design is typically mentioned in related work as the solution, but it is far from obvious what this entails in practice: what information about the hardware, software system, and workload is taken into account for decision-making is often implicit in related work.In this work, we propose a model-driven methodology for rightsizing offloading to benefit an end workload.Our methodology determines the target processing rate an offload device should have in a specific data processing system, without over-fitting.This helps designers pick the right hardware for offloading.Our methodology relies on modeling the system as a network of queues, based on different levels of information about the system, which allows determining the general usefulness of offload and the specific benefits to a workload of interest.We demonstrate how our methodology avoids under-or over-provisioning offload devices in a case study. Faeze Faghih, Maximilian Hüttner, Florin Dinu, Zsolt István |
DaMoN | 4 |
| 2025 | An Analysis of AWS Nitro Enclaves for Database WorkloadsabstractCloud databases have become prevalent, as evidenced by the rapid growth of systems such as BigQuery, Snowflake, and Databricks.Concurrently, there has been a significant increase in the requirements for secure data processing when outsourcing databases to the cloud.For this, Trusted Execution Environments (TEEs) have emerged as a key technology in the cloud, which is witnessed by the fact that all cloud providers offer TEEs in their service portfolios.However, Amazon Web Services' (AWS) approach to TEEs based on Nitro Enclaves fundamentally differs from that of other cloud providers like Microsoft and Google or standard technologies such as Intel SGX.In this paper, we thus set out the goal to understand the implications of using AWS Nitro Enclaves for cloud databases.Although Nitro Enclaves initially appear to be a promising platform for pure TEE performance, they come with significant limitations regarding communication with the Nitro Enclave.Our benchmark results provide insight into the performance and practical challenges of deploying database workloads in AWS Nitro Enclaves, offering valuable guidance for practitioners and researchers. Adrian Lutsch, Christian Franck, Muhammad El-Hindi, Zsolt István, Carsten Binnig |
DaMoN | 4 |
| 2025 | Benchmarking Analytical Query Processing in Intel SGXv2
Adrian Lutsch, Muhammad El-Hindi, Daniel Ritter 0001, Zsolt István, Carsten Binnig |
EDBT | 5 |
| 2025 | Analytical Buffer Sizing for Neural Network Inference Applications on FPGAsabstractA crucial and challenging step of implementing neural network inference on FPGAs is the sizing of intermediate buffers between the pipeline stages. Under-sizing buffers can lead to throughput loss and deadlocks, over-sizing wastes valuable device resources. Typically, buffer sizing is performed either with exhaustive search or solvers, accompanied by simulations. With modern neural networks rapidly growing in size, these approaches become infeasibly time consuming. In this work, we show how given the specialized domain of machine learning on FPGAs, it is feasible to dramatically speedup buffer sizing by avoiding the use of simulations and solvers. This is done by replacing them with analytical modeling and heuristics respectively. We incorporate our approach into the FINN compiler for neural network inference on FPGAs and show over three orders of magnitude speed up with buffer sizes closely matching exhaustive search results for a wide range of example models such as mobilenet-v1 and resnet50. Lukas Stasytis, Felix Paul Jentzsch, Zsolt István |
FPL | 3 |
| 2025 | Demonstration of Reflex: How SMPC Query Execution can be sped up through Efficient and Flexible Intermediate Result Size TrimmingabstractThere is growing interest in Secure Collaborative Analytics, but fully oblivious query execution in Secure Multi-Party Computation (MPC) settings is prohibitively expensive. Recent related works proposed different approaches to trimming the size of intermediate results between oblivious query operators, resulting in significant speedups at the cost of some controlled information leakage. In Reflex, we generalize these ideas into a flexible and efficient trimming method for the output of the oblivious operators, that we call Resizer. Resizers can be seamlessly integrated between MPC-based query operators. This allows for precisely controlling the security/performance trade-off on a per-operator and per-query basis. Our method has the potential to accelerate the performance of current oblivious query execution by up to 200 times compared to fully oblivious query execution, and by approximately 7 times compared to existing approaches with the same security guarantees. Our work lays down the foundation for a future MPC query planner that can pick different performance and security targets when composing physical plans. This demonstration showcases the benefits of Reflex. More precisely, it focuses on the integration of our proposed resizers into the oblivious query plan, significantly enhancing performance. Conference attendees will have the opportunity to observe the efficient trimming of intermediate results and, additionally, they will be able to configure the oblivious execution settings, ranging from fully oblivious to fully revealed. This hands-on experience will highlight the benefits of our proposal in various obliviousness scenarios. Long Gu, Shaza Zeitouni, Carsten Binnig, Zsolt István |
Proc. VLDB Endow. | 4 |
| 2024 | Workshop: Customizing Pre-Processing Algorithms for Streaming Sensor Data on Embedded Networked Devices
Dragos Lazea, Tudor Cioara, Anca Hangan, Zsolt István |
EWSN | 4 |
| 2024 | Zero-sided RDMA: Network-driven Data Shuffling for Disaggregated Heterogeneous Cloud DBMSsabstractIn this paper, we present a novel communication scheme called zero-sided RDMA, enabling data exchange as a native network service using a programmable switch. In contrast to one- or two-sided RDMA, in zero-sided RDMA, neither the sender nor the receiver is actively involved in data exchange. Zero-sided RDMA thus enables efficient RDMA-based data shuffling between heterogeneous hardware devices in a disaggregated setup without the need to implement a complete RDMA stack on each heterogeneous device or the need for a CPU that is co-located with the accelerator to coordinate the data transfer. As such, we think that zero-sided RDMA is a major building block to make efficient use of heterogeneous accelerators in future cloud DBMSs. In our evaluation, we show that zero-sided RDMA can outperform existing one-sided RDMA-based schemes for accelerator-to-accelerator communication and thus speed up typical distributed database operations such as joins. Matthias Jasny, Lasse Thostrup, Sajjad Tamimi, Andreas Koch 0001, Zsolt István, Carsten Binnig |
Proc. ACM Manag. Data | 5 |
| 2023 | Optimization Techniques for Hestenes-Jacobi SVD on FPGAsabstractMatrix decomposition, such as the Singular Value Decomposition (SVD) is an important compute-intensive task in a wide variety of fields, from radar and simulation to image processing and compression. In light of growing data sizes, accelerators, such as FPGAs, are often considered for SVD, with the goal of increasing the compute efficiency. However, to achieve high-performance computation of SVD, we need high parallelism. For that, a thorough reevaluation of the complexities involved in implementing the algorithm is necessary in light of hardware and algorithm advances. In this work, we investigate the Hestenes-Jacobi SVD (HJSVD) on FPGAs. Our findings show that the Hestenes-Jacobi method, while highly parallelizable, can become constrained in its hardware resource costs and requires careful tuning to achieve high throughput with input matrix sizes and degree of parallelism having an important effect on efficient pipelining of the architecture. We identify the key challenges in parallelizing the algorithm for modern workloads and incorporate three key optimizations: pipelining, the use of fixed-point arithmetic instead of floating-point, and the use of heterogeneous resources for vector rotations, not only DSPs. Lukas Stasytis, Zsolt István |
FPL | 2 |
| 2023 | Hybrid Anomaly Detection Model on Trusted IoT DevicesabstractMost machine learning proposals in the Internet of Things (IoT) are designed and evaluated on pre-processed datasets, where data acquisition and cleaning steps are often considered a black box. In addition, IoT environments have numerous challenges related to acquiring data from sensors, where sensitive data can be threatened by malicious users who seek to interfere with the communication channel or storage. Additionally, sensor data can also be affected by noise. Therefore, differentiating the type of threat/anomaly requires additional energy and computational resources. We propose to carry out data cleaning/anomaly techniques on the IoT device itself, not in the cloud servers but closer to the data source. Therefore, the IoT device sends trusted data to the Cloud. Among the benefits of this is the considerable reduction in the cost of implementation due to less movement of data between IoT devices and the Cloud. Consequently, we define three anomaly detection steps using smoothing filters, unsupervised learning, and deep learning techniques (i.e., hybrid model) to detect different variations of anomalies and threats while focusing on a small computational/memory footprint. The deployment of the hybrid model on AVR, Tensilica, and ARM microcontrollers showed that the last ones are an adequate target to implement the model because they best satisfy the necessary hardware requirements. The proposed model consumes 50KB of Flash and 12KB of RAM and processes data locally, achieving a bandwidth reduction of 60%. Finally, the hybrid model was tested in external datasets. P. Rosero-Montalvo, Zsolt István, Pinar Tözün, Wilmar Hernandez |
IEEE Internet Things J. | 2 |
| 2021 | Tutorial on the Internals of Permissioned Blockchains and on How to Build Applications with Hyperledger FabricabstractBlockchain is an emerging technology, considered increasingly often beyond the cryptocurrency world for business-to-business use-cases. In contrast to public blockchains such as Bitcoin, that are open systems in which anyone can participate, in business-to-business scenarios the membership of the service is controlled (permissioned blockchain). This permits the use of Byzantine fault tolerant (BFT) consensus protocols at the core of the service to establish a total order of transactions, instead of the more expensive Proof-of-Work-based consensus protocols. Permissioned blockchains typically set out to solve problems in the space where databases have traditionally resided, with the main difference being that the former decentralizes trust. There are numerous research proposals in the intersection of databases and blockchains. Sadly, there are still many misconceptions about this technology which leads to confusion in the community. The main goal of this primer is to give an overview of the relevant topics and provide pointers for further reading. Zsolt István |
EDBT | 1 |
| 2021 | In-Storage Computation of Histograms with differential privacyabstractNetwork-attached Smart Storage is becoming increasingly common in data analytics applications. It relies on processing elements, such as FPGAs, close to the storage medium to offload compute-intensive operations, reducing data movement across distributed nodes in the system. As a result, it can offer outstanding performance and energy efficiency. Modern data analytics systems are not only becoming more distributed they are also increasingly focusing on privacy policy compliance. This means that, in the future, Smart Storage will have to offload more and more privacy-related processing. In this work, we explore how the computation of differentially private (DP) histograms, a basic building block of privacy-preserving analytics, can be offloaded to FPGAs. By performing DP aggregation on the storage side, untrusted clients can be allowed to query the data in aggregate form without risking the leakage of personally identifiable information. We prototype our idea by extending an FPGA-based distributed key-value store with three new components. First, a histogram module, that processes values at 100Gbps line-rate. Second, a random noise generator that adds noise to final histogram according to the rules dictated by DP. Third, a mechanism to limit the rate at which key-value pairs can be used in histograms, to stay within the DP privacy budget. Andrei Tosa, Anca Hangan, Gheorghe Sebestyen, Zsolt István |
FPT | 4 |
| 2021 | The case for adding privacy-related offloading to smart storageabstractIt is important to ensure that personally identifiable information (PII) is protected within large distributed systems and is used only for intended purposes. Achieving this is challenging and several techniques have been proposed for privacy-preserving analytics, but they typically focus on the end hosts only. We argue that future storage solutions should include, in addition to emerging compute offload, also privacy-related operators. Since many privacy operators, such as perturbation and anonymization, take place as the very first step before other computations, query offload to a Smart Storage device might be only feasible in the future if privacy-related operators can also be offloaded. Claudiu Mihali, Anca Hangan, Gheorghe Sebestyen, Zsolt István |
SYSTOR | 4 |
| 2021 | Software-Defined Data Protection: Low Overhead Policy Compliance at the Storage Layer is Within Reach!abstractMost modern data processing pipelines run on top of a distributed storage layer, and securing the whole system, and the storage layer in particular, against accidental or malicious misuse is crucial to ensuring compliance to rules and regulations. Enforcing data protection and privacy rules, however, stands at odds with the requirement to achieve higher and higher access bandwidths and processing rates in large data processing pipelines. In this work we describe our proposal for the path forward that reconciles the two goals. We call our approach "Software-Defined Data Protection" (SDP). Its premise is simple, yet powerful: decoupling often changing policies from request-level enforcement allows distributed smart storage nodes to implement the latter at line-rate. Existing and future data protection frameworks can be translated to the same hardware interface which allows storage nodes to offload enforcement efficiently both for company-specific rules and regulations, such as GDPR or CCPA. While SDP is a promising approach, there are several remaining challenges to making this vision reality. As we explain in the paper, overcoming these will require collaboration across several domains, including security, databases and specialized hardware design. Zsolt István, Soujanya Ponnapalli, Vijay Chidambaram |
Proc. VLDB Endow. | 1 |
| 2020 | Let's add transactions to FPGA-based key-value stores!abstractIn recent years we have seen a proliferation of FPGA-based key value stores (KVSs) [1--3, 5--7, 10] driven by the need for more efficient large-scale data management and storage solutions. In this context, FPGAs are useful because they offer network-bound performance even with small key-value pairs and near-data processing in a fraction of the energy budget of regular servers. Even though the first FPGA-based key-value stores started appearing already in 2013 and have evolved significantly in the meantime, almost no attention has been paid to offering transactions. Today, however, that such systems are becoming increasingly practical, we need to ensure consistency guarantees for concurrent clients (transactions). This position paper makes the case that adding transaction support is not particularly expensive, compared to other parts of these systems, and in the future all FPGA-based KVSs should provide some form of transactional guarantees. Zsolt István |
DaMoN | 1 |
| 2019 | Design Patterns for Code Reuse in HLS Packet Processing PipelinesabstractHigh-level synthesis (HLS) allows developers to be more productive in designing FPGA circuits thanks to familiar programming languages and high-level abstractions. In order to create high-performance circuits, HLS tools, such as Xilinx Vivado HLS, require following specific design patterns and techniques. Unfortunately, when applied to network packet processing tasks, these techniques limit code reuse and modularity, requiring developers to use deprecated programming conventions. We propose a methodology for developing high-speed networking applications using Vivado HLS for C++, focusing on reusability, code simplicity, and overall performance. Following this methodology, we implement a class library (ntl) with several building blocks that can be used in a wide spectrum of networking applications. We evaluate the methodology by implementing two applications: a UDP stateless firewall and a key-value store cache designed for FPGA-based SmartNICs, both processing packets at 40Gbps line-rate. Haggai Eran, Lior Zeno, Zsolt István, Mark Silberstein |
FCCM | 3 |
| 2019 | Storing Parquet Tile by Tile: Application-Aware Storage with DeduplicationabstractDistributed storage in the cloud needs to offer both low latency and high bandwidth access to data and efficient use of storage capacity in order to keep up with emerging big data workloads. Deduplication has been successfully used to help with the latter requirement but it is often at odds with low latency data access. Deduplication ratios can be significantly increased if the storage nodes are aware of the file format and the ways clients interact with it - but implementing different file-type specific parsing on FPGAs for multiple tenants can be unfeasible due to area constraints. We show the benefits of making the storage system aware of the application through the example of Parquet files, a columnar format used in machine learning and big data frameworks to store and transfer datasets. We achieve high deduplication ratios by using a companion software library that allows Parquet files to be stored in a "divided" way. This makes deduplication more efficient and enables clients to access individual columns or meta-data fields selectively. At the same time, the storage nodes remain general purpose and can store and deduplicate arbitrary data. This work paves the way for in-storage processing for Parquet files and other columnar formats because the different columns can be accessed in a streaming fashion and their processing requires no specialized logic on the FPGA. Lucas Kuhring, Zsolt István |
FPL | 2 |
| 2019 | Specialize in Moderation - Building Application-aware Storage Services using FPGAs in the Datacenter
Lucas Kuhring, Eva García, Zsolt István |
HotStorage | 3 |
| 2019 | I Can't Believe It's Not (Only) Software! Bionic Distributed Storage for Parquet FilesabstractThere is a steady increase in the size of data stored and processed as part of data science applications, leading to bottlenecks and inefficiencies at various layers of the stack. One way of reducing such bottlenecks and increasing energy efficiency is by tailoring the underlying distributed storage solution to the application domain, using resources more efficiently. We explore this idea in the context of a popular column-oriented storage format used in big data workloads, namely Apache Parquet. Our prototype uses an FPGA-based storage node that offers high bandwidth data deduplication and a companion software library that exposes an API for Parquet file access. This way the storage node remains general purpose and could be shared by applications from different domains, while, at the same time, benefiting from deduplication well suited to Apache Parquet files and from selective reads of columns in the file. In this demonstration we show, on the one hand, that by relying on the FPGA's dataflow processing model, it is possible to implement in-line deduplication without increasing latencies significantly or reducing throughput. On the other hand, we highlight the benefits of implementing the application-specific aspects in a software library instead of FPGA circuits and how this enables, for instance, regular data science frameworks running in Python to access the data on the storage node and to offload filtering operations. Lucas Kuhring, Zsolt István |
Proc. VLDB Endow. | 2 |
| 2018 | A Flexible K-Means Operator for Hybrid DatabasesabstractThe K-means algorithm is widely used in unsupervised learning and data exploration. It is less used in analytical databases due to its high computational cost. K-means has been explored in great detail, mostly focusing on performance. However, in emerging hybrid CPU-FPGA databases where memory bandwidth is shared across software and hardware operators, two additional requirements arise. One is parameterization to avoid frequent reprogramming. The other is concurrent use to balance memory bandwidth and computation. Our design supports two operational modes that can be chosen at runtime, one for high query throughput and one for evaluating multiple clusters concurrently. The former targets speed up, while the latter targets efficient bandwidth utilization by increasing the amount of computation per input byte. Our design is competitive when compared to both existing FPGA-based solutions as well as highly optimized multi-core software implementations. Zhenhao He, David Sidler, Zsolt István, Gustavo Alonso |
FPL | 3 |
| 2018 | Providing Multi-tenant Services with FPGAs: Case Study on a Key-Value StoreabstractFPGAs can be used to speed up computation and data management tasks in various application domains. In cloud settings, however, high utilization is as important as high performance. In software it is common to co-locate different tenants' workloads on the same servers to increase utilization. Sharing an FPGA is more complex because applications take up physical space on the chip. Even though it is possible to physically partition the FPGA, tenants can have widely different requirements and their needs can also fluctuate over time. In this paper, we take a different approach and provide flexibility to the tenants who are interested in the same type of application but have different workloads and quality of service requirements. We demonstrate our approach of multi-tenant design using a key-value store service but the ideas generalize to other network-facing services as well. A key challenge of multi-tenancy is to efficiently share the underlying hardware while enforcing strict data and performance isolation between tenants. In this paper we demonstrate that, by following a single-pipeline design principle, it is possible to control each tenant's share of network bandwidth and computational resources even for complex, distributed operations. Furthermore, we show how state-machine based logic on the FPGA can be made tenant-aware without introducing significant context-switching overhead. Finally, our hardware design provides flexibility for changing per-tenant shares, allowing the same circuit to be used by one or multiple tenants without performance loss. Zsolt István, Gustavo Alonso, Ankit Singla |
FPL | 1 |
| 2017 | doppioDB: A hardware accelerated databaseabstractRelational databases provide a wealth of functionality to a wide range of applications. Yet, there are tasks for which they are less than optimal, for instance when processing becomes more complex (e.g., regular expression evaluation, data analytics) or the data is less structured (e.g., text or long strings). With the increasing amount of user-generated data stored in relational databases, there is a growing need to analyze unstructured text data. At the same time more complex analytical operators are required to extract useful information from the vast amount of collected data. However, many analytical operators incur a significant compute complexity not suitable to database engines where multiple queries share the available resources. In this demonstration we show the benefit of using specialized hardware for such tasks and highlight the importance of a flexible, reusable mechanism for extending database engines with hardware-based operators. Our hybrid database engine, doppioDB, is deployed on an emerging Xeon+FPGA multicore architecture where the CPU and FPGA have cache-coherent access to the same memory, such that the hardware operators can directly access the database tables. The demonstration is illustrating the acceleration benefits of hardware operators, as well as doppioDB's flexibility in accommodating changing workloads. David Sidler, Muhsen Owaida, Zsolt István, Kaan Kara, Gustavo Alonso |
FPL | 3 |
| 2017 | Accelerating Pattern Matching Queries in Hybrid CPU-FPGA ArchitecturesabstractTaking advantage of recently released hybrid multicore architectures, such as the Intel's Xeon+FPGA machine, where the FPGA has coherent access to the main memory through the QPI bus, we explore the benefits of specializing operators to hardware. We focus on two commonly used SQL operators for strings: LIKE, and REGEXP_LIKE, and provide a novel and efficient implementation of these operators in reconfigurable hardware. We integrate the hardware accelerator into MonetDB, a main-memory column store, and demonstrate a significant improvement in response time and throughput. Our Hardware User Defined Function (HUDF) can speed up complex pattern matching by an order of magnitude in comparison to the database running on a 10-core CPU. The insights gained from integrating hardware based string operators into MonetDB should also be useful for future designs combining hardware specialization and databases. David Sidler, Zsolt István, Muhsen Owaida, Gustavo Alonso |
SIGMOD Conference | 2 |
| 2017 | doppioDB: A Hardware Accelerated DatabaseabstractRelational databases provide a wealth of functionality to a wide range of applications. Yet, there are tasks for which they are less than optimal, for instance when processing becomes more complex (e.g., matching regular expressions) or the data is less structured (e.g., text or long strings). In this demonstration we show the benefit of using specialized hardware for such tasks and highlight the importance of a flexible, reusable mechanism for extending database engines with hardware-based operators. David Sidler, Zsolt István, Muhsen Owaida, Kaan Kara, Gustavo Alonso |
SIGMOD Conference | 2 |
| 2017 | Caribou: Intelligent Distributed StorageabstractThe ever increasing amount of data being handled in data centers causes an intrinsic inefficiency: moving data around is expensive in terms of bandwidth, latency, and power consumption, especially given the low computational complexity of many database operations. In this paper we explore near-data processing in database engines, i.e., the option of offloading part of the computation directly to the storage nodes. We implement our ideas in Caribou, an intelligent distributed storage layer incorporating many of the lessons learned while building systems with specialized hardware. Caribou provides access to DRAM/NVRAM storage over the network through a simple key-value store interface, with each storage node providing high-bandwidth near-data processing at line rate and fault tolerance through replication. The result is a highly efficient, distributed, intelligent data storage that can be used to both boost performance and reduce power consumption and real estate usage in the data center thanks to the micro-server architecture adopted. Zsolt István, David Sidler, Gustavo Alonso |
Proc. VLDB Endow. | 1 |
| 2016 | Runtime Parameterizable Regular Expression Operators for DatabasesabstractRelational databases execute user queries through operator trees, where each operator has a well defined interface and a specific task (e.g., arithmetic function, pattern matching, aggregation, etc.). Hardware acceleration of compute intensive operators is a promising prospect but it comes with challenges. Databases execute tens of thousands of different queries per second. Thus, if only one specific instantiation of an operator is supported by the accelerator, it will have little effect on the overall workload. In this paper we explore the tradeoff between resource efficiency and expression complexity for an FPGA accelerator targeting string-matching operators (LIKE and REGEXP_LIKE in SQL). This tradeoff is complex. For instance, the FPGA not always wins: simple queries that can be answered from indexes run faster on the CPU. On complex regular expressions, the FPGA is faster but needs to be parametrized at runtime to be able to support different queries. For very long patterns, the entire expression might not fit into the FPGA circuit and a combined mode CPU-FPGA must be chosen. We evaluate our design on a heterogeneous multi-core machine in which the FPGA has cache coherent access to the CPU memory. In addition to the string matching circuit, we also show how to implement database page parsing logic so as to be able to work directly on the same memory data structures as the database engine. Zsolt István, David Sidler, Gustavo Alonso |
FCCM | 1 |
| 2016 | Low-latency TCP/IP stack for data center applicationsabstractTCP/IP is widely used both in the Internet as well as in data centers. The protocol makes very few assumptions about the underlying network and provides useful guarantees such as reliable transmission, in-order delivery, or control flow. The price for this functionality is complexity, latency, and computational overhead, which is especially pronounced in software implementations. While for Internet communication this is acceptable, the overhead is too high in data centers. In this paper, we explore how to optimize a TCP/IP stack running on an FPGA for data center applications with an emphasis on data processing (e.g., key value stores). Using a key-value store and a low-latency consensus protocol implemented on an FPGA as an example of the requirements that arise in data centers, we provide an extensive analysis of the overheads of TCP/IP and the solutions that can be adopted to minimize such an overhead. The proposed optimized TCP/IP stack minimizes tail latencies (a key metric in distributed data processing) and is efficiently implemented so as to be able to share the FPGA with application logic. David Sidler, Zsolt István, Gustavo Alonso |
FPL | 2 |
| 2016 | Consensus in a Box: Inexpensive Coordination in Hardware
Zsolt István, David Sidler, Gustavo Alonso, Marko Vukolic |
NSDI | 1 |
| 2015 | Building a distributed key-value store with FPGA-based microserversabstractEnergy efficiency is one of the major challenges in datacenters, and a promising way to tackle it are microservers. These scaled down machines with smaller CPUs, less peripherals and tighter integration improve energy efficiency, but often at the expense of lower performance. In this work we explore the tailoring of standard software components to specialized hardware as a way to get the energy efficiency of microservers without compromising performance. Our specialized microserver implements memcached, a common component in many web stacks, on a cluster of FPGAs. The design explores aspects such as pipelining techniques, tight integration with the network stack, dealing with the memory bottleneck, and shows how to build a complete system out of individual microservers. To our knowledge this is the first stand-alone FPGA-based solution that can be used as a drop-in replacement for the software version. Beyond the per-node performance, in this demo we focus on the replication and the integration aspects of our system. We run a common benchmark on a PostgreSQL database with a two-node deployment of FPGAs acting as a cache for query results. Zsolt István, David Sidler, Gustavo Alonso |
FPL | 1 |
| 2015 | A Hash Table for Line-Rate Data ProcessingabstractFPGA-based data processing is becoming increasingly relevant in data centers, as the transformation of existing applications into dataflow architectures can bring significant throughput and power benefits. Furthermore, a tighter integration of computing and network is appealing, as it overcomes traditional bottlenecks between CPUs and network interfaces, and dramatically reduces latency. In this article, we present the design of a novel hash table, a fundamental building block used in many applications, to enable data processing on FPGAs close to the network. We present a fully pipelined design capable of sustaining consistent 10Gbps line-rate processing by deploying a concurrent mechanism to handle hash collisions. We address additional design challenges such as support for a broad range of key sizes without stalling the pipeline through careful matching of lookup time with packet reception time. Finally, the design is based on a scalable architecture that can be easily parameterized to work with different memory types operating at different access speeds and latencies. We have tested the proposed hash table in an FPGA-based memcached appliance implementing a main-memory key-value store in hardware. The hash table is used to index 2 million entries in 24GB of external DDR3 DRAM while sustaining 13 million requests per second, the maximum packet rate that can be achieved with UDP packets on a 10Gbps link for this application. Zsolt István, Gustavo Alonso, Michaela Blott, Kees A. Vissers |
ACM Trans. Reconfigurable Technol. Syst. | 1 |
| 2014 | Histograms as a side effect of data movement for big dataabstractHistograms are a crucial part of database query planning but their computation is resource-intensive. As a consequence, generating histograms on database tables is typically performed as a batch job, separately from query processing. In this paper, we show how to calculate statistics as a side effect of data movement within a DBMS using a hardware accelerator in the data path. This accelerator analyzes tables as they are transmitted from storage to the processing unit, and provides histograms on the data retrieved for queries at virtually no extra performance cost. To evaluate our approach, we implemented this accelerator on an FPGA. This prototype calculates histograms faster and with similar or better accuracy than commercial databases. Moreover, the FPGA can provide various types of histograms such as Equi-depth, Compressed, or Max-diff on the same input data in parallel, without additional overhead. Zsolt István, Louis Woods, Gustavo Alonso |
SIGMOD Conference | 1 |
| 2014 | Ibex - An Intelligent Storage Engine with Support for Advanced SQL Off-loadingabstractModern data appliances face severe bandwidth bottlenecks when moving vast amounts of data from storage to the query processing nodes. A possible solution to mitigate these bottlenecks is query off-loading to an intelligent storage engine , where partial or whole queries are pushed down to the storage engine. In this paper, we present Ibex , a prototype of an intelligent storage engine that supports off-loading of complex query operators. Besides increasing performance, Ibex also reduces energy consumption, as it uses an FPGA rather than conventional CPUs to implement the off-load engine. Ibex is a hybrid engine, with dedicated hardware that evaluates SQL expressions at line-rate and a software fallback for tasks that the hardware engine cannot handle. Ibex supports GROUP BY aggregation, as well as projection - and selection - based filtering. GROUP BY aggregation has a higher impact on performance but is also a more challenging operator to implement on an FPGA. Louis Woods, Zsolt István, Gustavo Alonso |
Proc. VLDB Endow. | 2 |
| 2013 | Multi-threaded Active Objects
Ludovic Henrio, Fabrice Huet, Zsolt István |
COORDINATION | 3 |
| 2013 | A flexible hash table design for 10GBPS key-value stores on FPGASabstractCommon web infrastructure relies on distributed main memory key-value stores to reduce access load on databases, thereby improving both performance and scalability of web sites. As standard cloud servers provide sub-linear scalability and reduced power efficiency to these kinds of scale-out workloads, we have investigated a novel dataflow architecture for key-value stores with the aid of FPGAs which can deliver consistent 10Gbps throughput. In this paper, we present the design of a novel hash table which forms the centre piece of this dataflow architecture. The fully pipelined design can sustain consistent 10Gbps line-rate performance by deploying a concurrent mechanism to handle hash collisions. We address problems such as support for a broad range of key sizes without stalling the pipeline through careful matching of lookup time with packet reception time. Finally, the design is based on a scalable architecture that can be easily parametrized to work with different memory types operating at different access speeds and latencies. We deployed this hash table in a memcached prototype to index 2 million entries in 24GBytes of external DDR3 DRAM while sustaining 13 million requests per second for UDP binary encoded memcached packets which is the maximum packet rate that can be achieved with memcached on a 10Gbps link. Zsolt István, Gustavo Alonso, Michaela Blott, Kees A. Vissers |
FPL | 1 |
| 2013 | Hybrid FPGA-accelerated SQL query processingabstractIbex [1] is a novel database storage engine featuring hybrid, FPGA-accelerated query processing. The first prototype of Ibex has been implemented within the open-source MySQL database. In Ibex, an FPGA is inserted into the data path between disk and CPU to act as a query off-loading engine, operating on the stream of data towards the query processor. As a result, the volume of data hitting the CPU is substantially reduced, thereby decreasing energy consumption while increasing performance at the same time. Louis Woods, Zsolt István, Gustavo Alonso |
FPL | 2 |
| 2011 | Adapting Active Objects to Multicore ArchitecturesabstractThere are several programming paradigms that help programmers write efficient and verifiable code for distributed environments. These solutions, however, often lack proper support for local parallelism. In this article we try to improve existing solutions for providing a distributed, highly parallel framework that is easy to program. We propose an extension to the active object programming model which optimizes the local performance of applications by harnessing the full computing power of multi-core CPUs. The need for explicit locking mechanisms is reduced by the addition of meta-information to the methods in the source code. This paper describes this language-independent meta-information, and the way we intend to use it for parallelizing execution inside an active object. Ludovic Henrio, Fabrice Huet, Zsolt István, Gheorghe Sebestyen |
ISPDC | 3 |