VLDB 2026 Research / reviewers in the wild / expert
Xiaoqi Ren
dblp:146/8107
· DBLP profile ↗
12ranked-venue papers
5as first author
4since 2021 · last 2026
0000-0002-1121-9046ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Systems, architecture and hardware · 5 · 2 first-author · 1 since 2021Artificial intelligence and machine learning · 4 · 1 first-author · 4 since 2021Computer networks · 4 · 3 first-authorGraphics, computer vision, multimedia, augmented reality and games · 2 · 2 since 2021Software engineering, systems software and programming languages · 1 · 1 first-author
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.
| Artificial intelligence
3 papers |
Language models and text generation · 32% Learning paradigms · 32% Multi-agent systems · 14% | |
| Computer architecture, parallel and distributed computing, and storage systems
5 papers |
Cloud and datacenter computing · 55% Energy-efficient computing · 29% Distributed systems · 16% | |
| Databases, data mining, and information retrieval
2 papers |
Distributed and cloud data management · 100% |
Topics — the 21 heaviest of 24, each with the papers that count most for it
| Topic | Weight | Papers | Last | Evidence papers |
|---|---|---|---|---|
Machine learning › Learning paradigms
continual learning |
1.1 | 2 | 2022 | DualPrompt: Complementary Prompting for Rehearsal-Free Continual Learning · ECCV (26) 2022 Learning to Prompt for Continual Learning · CVPR 2022 |
Knowledge, reasoning and agents › Planning, search and constraint satisfaction › planning
agent planning |
1.0 | 1 | 2026 | COMPASS: Enhancing Agent Long-Horizon Reasoning with Evolving Context · ACL (1) 2026 |
Natural language and speech › Language models and text generation
large language model reasoning |
1.0 | 1 | 2026 | COMPASS: Enhancing Agent Long-Horizon Reasoning with Evolving Context · ACL (1) 2026 |
Knowledge, reasoning and agents › Multi-agent systems
LLM-based multi-agent systems |
1.0 | 1 | 2026 | COMPASS: Enhancing Agent Long-Horizon Reasoning with Evolving Context · ACL (1) 2026 |
Natural language and speech › Language models and text generation › large language model reasoning › multi-step reasoning
long-horizon reasoning |
1.0 | 1 | 2026 | COMPASS: Enhancing Agent Long-Horizon Reasoning with Evolving Context · ACL (1) 2026 |
Distributed and cloud data management
data placement |
0.6 | 2 | 2018 | Datum: Managing Data Purchasing and Data Placement in a Geo-Distributed Data Market · IEEE/ACM Trans. Netw. 2018 Joint Data Purchasing and Data Placement in a Geo-Distributed Data Market · SIGMETRICS 2016 |
Energy-efficient computing
datacenter power management |
0.6 | 2 | 2018 | A Spot Capacity Market to Increase Power Infrastructure Utilization in Multi-tenant Data Centers · HPCA 2018 A market approach for handling power emergencies in multi-tenant data center · HPCA 2016 |
Cloud and datacenter computing › multi-tenancy
multi-tenant datacenter |
0.6 | 2 | 2018 | A Spot Capacity Market to Increase Power Infrastructure Utilization in Multi-tenant Data Centers · HPCA 2018 A market approach for handling power emergencies in multi-tenant data center · HPCA 2016 |
Machine learning › Learning paradigms › continual learning
prompt-based continual learning |
0.6 | 1 | 2022 | DualPrompt: Complementary Prompting for Rehearsal-Free Continual Learning · ECCV (26) 2022 |
Computer vision › Vision and language › vision-language model
prompt learning |
0.6 | 1 | 2022 | Learning to Prompt for Continual Learning · CVPR 2022 |
Machine learning › Learning paradigms › continual learning
rehearsal-free continual learning |
0.6 | 1 | 2022 | DualPrompt: Complementary Prompting for Rehearsal-Free Continual Learning · ECCV (26) 2022 |
Distributed systems › distributed data processing
straggler mitigation |
0.3 | 2 | 2015 | GRASS: Trimming Stragglers in Approximation Analytics · NSDI 2014 Hopper: Decentralized Speculation-aware Cluster Scheduling at Scale · SIGCOMM 2015 |
Distributed and cloud data management › data placement
geo-distributed data placement |
0.2 | 1 | 2016 | Joint Data Purchasing and Data Placement in a Geo-Distributed Data Market · SIGMETRICS 2016 |
Cloud and datacenter computing
data market |
0.2 | 1 | 2016 | Joint Data Purchasing and Data Placement in a Geo-Distributed Data Market · SIGMETRICS 2016 |
Cloud and datacenter computing
geo-distributed cloud |
0.2 | 1 | 2016 | Joint Data Purchasing and Data Placement in a Geo-Distributed Data Market · SIGMETRICS 2016 |
Energy-efficient computing › power management
power capping |
0.2 | 1 | 2016 | A market approach for handling power emergencies in multi-tenant data center · HPCA 2016 |
Cloud and datacenter computing
resource management |
0.2 | 1 | 2016 | Joint Data Purchasing and Data Placement in a Geo-Distributed Data Market · SIGMETRICS 2016 |
Cloud and datacenter computing
cluster resource management and scheduling |
0.2 | 1 | 2015 | Hopper: Decentralized Speculation-aware Cluster Scheduling at Scale · SIGCOMM 2015 |
Distributed systems
distributed scheduling |
0.2 | 1 | 2015 | Hopper: Decentralized Speculation-aware Cluster Scheduling at Scale · SIGCOMM 2015 |
Network optimization and economics › mechanism design
market mechanism |
0.2 | 2 | 2018 | A Spot Capacity Market to Increase Power Infrastructure Utilization in Multi-tenant Data Centers · HPCA 2018 A market approach for handling power emergencies in multi-tenant data center · HPCA 2016 |
Cloud and datacenter computing › cluster resource management and scheduling
cluster scheduling |
0.1 | 1 | 2014 | GRASS: Trimming Stragglers in Approximation Analytics · NSDI 2014 |
Methods — techniques the papers use, named apart from their topics
supply function bidding · 1.2prompt tuning · 1.1test-time scaling · 1.0post-training · 1.0hierarchical agent architecture · 1.0vision transformer · 0.6pre-trained model · 0.6approximation algorithm · 0.5NP-hardness analysis · 0.5speculative execution · 0.2
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | COMPASS: Enhancing Agent Long-Horizon Reasoning with Evolving ContextabstractLong-horizon tasks that require sustained reasoning and multiple tool interactions remain challenging for LLM agents: small errors compound across steps, and even state-of-the-art models often hallucinate or lose coherence.We identify context management as the central bottleneck-extended histories cause agents to overlook critical evidence or become distracted by irrelevant information, thus failing to replan or reflect from previous mistakes.To address this, we propose COMPASS (Context-Organized Multi-Agent Planning and Strategy System), a lightweight hierarchical framework that separates tactical execution, strategic oversight, and context organization into three specialized components: (1) a Main Agent that performs reasoning and tool use, (2) a Meta-Thinker that monitors progress and issues strategic interventions, and (3) a Context Manager that maintains concise, relevant progress briefs for different reasoning stages.Across three challenging benchmarks-GAIA, BrowseComp, and Humanity's Last Exam-COMPASS improves accuracy by up to 20% relative to both single-and multi-agent baselines.We further introduce a test-time scaling extension that elevates performance to match established DeepResearch agents, and a posttraining pipeline that delegates context management to smaller models for enhanced efficiency. Guangya Wan, Mingyang Ling 0001, Xiaoqi Ren, Rujun Han, Sheng Li 0001 |
ACL (1) | 3 |
| 2025 | Scalable MARL for Cooperative Exploration with Dynamic Robot Populations via Graph-Based Information AggregationabstractThis study addresses the challenge of multi-robot cooperative exploration under limited local observations in environments with dynamic robot populations. To achieve efficient area coverage within constrained timeframes, we propose the Multi-Robot Informative Planner (MIP), a novel reinforcement learning (RL)-based planning module. The core component of MIP is the Neighborhood Information Aggregator, which employs a graph neural network (GNN) to integrate local neighborhood information for each robot. Our design enhances sample efficiency by minimizing information requirements while ensuring scalability across environments with varying robot numbers. To generate high-quality, expressive neighborhood feature representations, we utilize Graphical Mutual Information (GMI) to maximize the correlation between neighboring robots’ input features and their high-level hidden representations. Furthermore, MIP incorporates the Spatial-Neighborhood Transformer, which captures spatial features and inter-robot interactions through spatial self-attention mechanisms. These components collectively form the Multi-Robot Neural Informative Mapping (MRNIM) framework, outperforming traditional benchmarks in Habitat simulator. Xiaoqi Ren, Guanglong Du, Zhuoyao Wang 0001, Xueqian Wang 0001, Quanlong Guan, Xiaojian Qiu |
IROS | 1 |
| 2022 | Learning to Prompt for Continual LearningabstractThe mainstream paradigm behind continual learning has been to adapt the model parameters to non-stationary data distributions, where catastrophic forgetting is the central challenge. Typical methods rely on a rehearsal buffer or known task identity at test time to retrieve learned knowl-edge and address forgetting, while this work presents a new paradigm for continual learning that aims to train a more succinct memory system without accessing task identity at test time. Our method learns to dynamically prompt (L2P) a pre-trained model to learn tasks sequen-tially under different task transitions. In our proposed framework, prompts are small learnable parameters, which are maintained in a memory space. The objective is to optimize prompts to instruct the model prediction and ex-plicitly manage task-invariant and task-specific knowledge while maintaining model plasticity. We conduct comprehen-sive experiments under popular image classification bench-marks with different challenging continual learning set-tings, where L2P consistently outperforms prior state-of-the-art methods. Surprisingly, L2P achieves competitive results against rehearsal-based methods even without a re-hearsal buffer and is directly applicable to challenging task-agnostic continual learning. Source code is available at https://github.com/google-research/12p. Zifeng Wang 0002, Chen-Yu Lee, Han Zhang 0010, Ruoxi Sun 0002, Xiaoqi Ren, Guolong Su, Vincent Perot, Jennifer G. Dy, Tomas Pfister |
CVPR | 6 |
| 2022 | DualPrompt: Complementary Prompting for Rehearsal-Free Continual Learning
Zifeng Wang 0002, Sayna Ebrahimi, Ruoxi Sun 0002, Han Zhang 0010, Chen-Yu Lee, Xiaoqi Ren, Guolong Su, Vincent Perot, Jennifer G. Dy, Tomas Pfister |
ECCV (26) | 7 |
| 2018 | A Spot Capacity Market to Increase Power Infrastructure Utilization in Multi-tenant Data CentersabstractDespite the common practice of oversubscription, power capacity is largely under-utilized in data centers. A significant factor driving this under-utilization is fluctuation of the aggregate power demand, resulting in unused “spot (power) capacity”. In this paper, we tap into spot capacity for improving power infrastructure utilization in multi-tenant data centers, an important but under-explored type of data center where multiple tenants house their own physical servers. We propose a novel market, called SpotDC, to allocate spot capacity to tenants on demand. Specifically, SpotDC extracts tenants' racklevel spot capacity demand through an elastic demand function, based on which the operator sets the market price for spot capacity allocation. We evaluate SpotDC using both testbed experiments and simulations, demonstrating that SpotDC improves power infrastructure utilization and creates a “win-win” situation: the data center operator increases its profit (by nearly 10%), while tenants improve their performance (by 1.2-1.8x on average compared to the no spot capacity case, yet at a marginal cost). Mohammad A. Islam 0001, Xiaoqi Ren, Shaolei Ren, Adam Wierman |
HPCA | 2 |
| 2018 | Datum: Managing Data Purchasing and Data Placement in a Geo-Distributed Data Market
Xiaoqi Ren, Palma London, Juba Ziani, Adam Wierman |
IEEE/ACM Trans. Netw. | 1 |
| 2016 | A market approach for handling power emergencies in multi-tenant data centerabstractPower oversubscription in data centers may occasionally trigger an emergency when the aggregate power demand exceeds the capacity. Handling such an emergency requires a graceful power capping solution that minimizes the performance loss. In this paper, we study power capping in a multi-tenant data center where the operator supplies power to multiple tenants that manage their own servers. Unlike owner-operated data centers, the operator lacks control over tenants' servers. To address this challenge, we propose a novel market mechanism based on supply function bidding, called COOP, to financially incentivize and coordinate tenants' power reduction for minimizing total performance loss (quantified in performance cost) while satisfying multiple power capping constraints. We build a prototype to show that COOP is efficient in terms of minimizing the total performance cost, even compared to the ideal but infeasible case that assumes the operator has full control over tenants' servers. We also demonstrate that COOP is "win-win", increasing the operator's profit (through oversubscription) and reducing tenants' cost (through financial compensation for their power reduction during emergencies). Mohammad A. Islam 0001, Xiaoqi Ren, Shaolei Ren, Adam Wierman |
HPCA | 2 |
| 2016 | Joint Data Purchasing and Data Placement in a Geo-Distributed Data MarketabstractThis paper studies design challenges faced by a geo-distributed cloud data market: which data to purchase (data purchasing) and where to place/replicate the data (data placement). We show that the joint problem of data purchasing and data placement within a cloud data market is NP-hard in general. However, we give a provably optimal algorithm for the case of a data market made up of a single data center, and then generalize the structure from the single data center setting and propose Datum, a near-optimal, polynomial-time algorithm for a geo-distributed data market. Xiaoqi Ren, Palma London, Juba Ziani, Adam Wierman |
SIGMETRICS | 1 |
| 2015 | Hopper: Decentralized Speculation-aware Cluster Scheduling at ScaleabstractAs clusters continue to grow in size and complexity, providing scalable and predictable performance is an increasingly important challenge. A crucial roadblock to achieving predictable performance is stragglers, i.e., tasks that take significantly longer than expected to run. At this point, speculative execution has been widely adopted to mitigate the impact of stragglers. However, speculation mechanisms are designed and operated independently of job scheduling when, in fact, scheduling a speculative copy of a task has a direct impact on the resources available for other jobs. In this work, we present Hopper, a job scheduler that is speculation-aware, i.e., that integrates the tradeoffs associated with speculation into job scheduling decisions. We implement both centralized and decentralized prototypes of the Hopper scheduler and show that 50% (66%) improvements over state-of-the-art centralized (decentralized) schedulers and speculation strategies can be achieved through the coordination of scheduling and speculation. Xiaoqi Ren, Ganesh Ananthanarayanan, Adam Wierman, Minlan Yu |
SIGCOMM | 1 |
| 2015 | Greening multi-tenant data center demand response
Niangjun Chen, Xiaoqi Ren, Shaolei Ren, Adam Wierman |
Perform. Evaluation | 2 |
| 2014 | GRASS: Trimming Stragglers in Approximation Analytics
Ganesh Ananthanarayanan, Chien-Chun Hung, Xiaoqi Ren, Ion Stoica, Adam Wierman, Minlan Yu |
NSDI | 3 |
| 2013 | Sampling-based Smoothed Analysis for network algorithm evaluationabstractAccurate performance evaluation for network algorithms is vital to meet various requirements of different applications, such as QoS, network security, traffic engineering. Although worst-case and average-case analysis are widely used in algorithm evaluation, they are often insufficient due to the lack of practicality. Smoothed Analysis (SA) introduces a new concept of smoothed complexity, remedying the shortcomings in worst-case and average-case analysis. However, recent research towards SA focuses on theoretical evaluation, and thus those methods tend to be too complicated for the analysis of network algorithms. To address the problem, Sampling-based Smoothed Analysis (SSA) for network algorithm evaluation is proposed. SSA extends feasibility for practical performance evaluation and achieves promising experimental results. As examples, two algorithms for typical network problem are evaluated using the proposed SSA framework, and the results explicitly illustrate their significant performance difference in spite of the same theoretical worst-case complexity. Besides evaluation accuracy, SSA also provide more insight for algorithms to facilitate current algorithms improvement and new algorithms design. Xiaoqi Ren, Zhi Liu 0001, Yaxuan Qi, Jun Li 0003, Shanghua Teng |
GLOBECOM | 1 |