Distributed Applications and Interoperable Systems: 22nd IFIP WG 6.1 International Conference, DAIS 2022, Held as Part of the 17th International Federated Conference on Distributed Computing Techniques, DisCoTec 2022, Lucca, Italy, June 13-17, 2022, Proceedings

Foreword
Preface
Organization
Contents
Blockchains and Cryptocurrencies
An Evaluation of Blockchain Application Requirements and Their Satisfaction in Hyperledger Fabric
	1 Introduction
	2 Related Work
	3 Background
	4 Methodology
	5 Requirements Analysis
		5.1 Electronic Voting (EVote)
		5.2 Supply Chains (IBM Food Trust and GoDirect Trade)
		5.3 Healthcare (Change Healthcare)
		5.4 Banking (VISA B2B Connect)
	6 How HLF Meets Enterprise Requirements
		6.1 Resilience Requirements
		6.2 Performance Requirements
	7 Performance Evaluation
		7.1 Multi Ordering Services Performance
		7.2 Mixed Workloads
		7.3 Discussion
	8 Conclusion
	References
Using SGX for Meta-Transactions Support in Ethereum DApps
	1 Introduction
	2 Background
	3 Basic Solution Design
	4 Discussion and Open Directions
	5 Conclusion
	References
Understanding Cryptocoins Trends Correlations
	1 Introduction
	2 Background
	3 Preliminary Evaluation
	4 Related Work
	5 Conclusion and Future Work
	References
Rebop: Reputation-Based Incentives in Committee-Based Blockchains
	1 Introduction
	2 Committee-Based Blockchains
	3 System and Protocol Model
	4 Attacks and Incentives
	5 Rebop: Reputation-Based Reward Opportunity
	6 Incentive Analysis
		6.1 Baseline Analysis
		6.2 Collusion Resistance of Rebop
		6.3 Preventing Byzantine Attacks
	7 Simulation Results
		7.1 Resistance Against Colluding Processes
		7.2 Byzantine Resistance
	8 Related Works
	9 Conclusion
	References
Fault Tolerance
Lesser Evil: Embracing Failure to Protect Overall System Availability
	1 Introduction
	2 Problem Statement
	3 Erlang
	4 Lesser Evil
		4.1 Entities
		4.2 Badness
		4.3 Strategy
		4.4 Compensating Actions
		4.5 Architecture
		4.6 Discussion
		4.7 Note on Applicability
	5 Evaluation
		5.1 Test Subject
		5.2 Configuration
		5.3 Experiments
		5.4 Results
		5.5 Conclusion and Limitations
		5.6 Threats to Validity
	6 Related Work
	7 Conclusion
	References
Failure Root Cause Analysis for Microservices, Explained
	1 Introduction
	2 Motivating Scenario
	3 Declarative Failure Root Cause Analysis
	4 Prototype Implementation
	5 Evaluation
	6 Related Work
	7 Conclusions
	References
Trusted Execution, Deep Learning, and IoT
Attestation Mechanisms for Trusted Execution Environments Demystified
	1 Introduction
	2 Attestation
		2.1 Local Attestation
		2.2 Remote Attestation
		2.3 Mutual Attestation
	3 Issuing Attestations Using TEEs
		3.1 TEE Cornerstone Features
		3.2 Trusted Environments and Remote Attestation
		3.3 Intel SGX
		3.4 Arm TrustZone Architectures
		3.5 AMD SEV
		3.6 RISC-V Architectures
	4 Future Work
	5 Conclusion
	References
Accelerate Model Parallel Deep Learning Training Using Effective Graph Traversal Order in Device Placement
	1 Introduction
	2 Preliminaries
		2.1 Device Placement
		2.2 Placeto
		2.3 Graph Traversal Order
	3 Graph Traversal Orders in Device Placement
		3.1 Challenges in Device Placement
		3.2 Impact of Graph Traversal Orders
	4 Evaluation
		4.1 Datasets
		4.2 Experiment Setup
		4.3 Results and Analysis
		4.4 Discussion and Guidelines
	5 Related Work
	6 Conclusion
	References
Analysis of the Impact of Interaction Patterns and IoT Protocols on Energy Consumption of IoT Consumer Applications
	1 Introduction
	2 Consuming IoT Applications: Architecture, Interaction Patterns and Protocols
		2.1 Distributed IoT Architecture
		2.2 Interaction Patterns
		2.3 IoT Protocols
	3 Related Work
	4 Experimental Methodology
		4.1 Experimental Setup
		4.2 Process to Isolate the Communication Energy Consumption
		4.3 Experimental Plan
		4.4 Threats to Validity
	5 Analysis
		5.1 (RQ1) Impact of the Interaction Pattern
		5.2 (RQ2) Impact of the Application Protocol
		5.3 (RQ3) Impact of the QoS in MQTT
		5.4 (RQ4) Impact of the Payload
		5.5 Guidelines for IoT Consumer Application Designers
	6 Conclusions
	References
Elastic and Scalable Systems
The HDFS Replica Placement Policies: A Comparative Experimental Investigation
	1 Introduction
	2 Data Replication in HDFS
		2.1 Block Re-replication
		2.2 Replica Rearrangement
	3 Replica Placement Policies
	4 Related Work
	5 Experimentation
		5.1 First Stage: Data Load
		5.2 Second Stage: Block Re-replication
		5.3 Third Stage: Replica Rearrangement
	6 Conclusions and Future Work
	References
An Elastic and Scalable Topic-Based Pub/Sub System Using Deep Reinforcement Learning
	1 Introduction
	2 System Architecture and Model
		2.1 Apache Kafka
		2.2 System Architecture and Model
	3 Proposed Methodology
		3.1 Deep Reinforcement Learning
		3.2 Scaling Decisions
	4 Evaluation
	5 Related Work
	6 Conclusions
	References
Invited Paper
Challenges in Automated Measurement of Pedestrian Dynamics
	1 Introduction
	2 Automated Measurement of Pedestrian Behavior
	3 Protecting Privacy Through Detection k-anonymity
		3.1 Approach
		3.2 Evaluation
		3.3 Reflection
	4 Protecting Privacy Through Homomorphically Encrypted Bloom Filters
		4.1 Approach
		4.2 Evaluation
		4.3 Reflection
	5 Other Challenges
		5.1 Behavior of Carry-On Devices and (non)overlapping Sensor Ranges
		5.2 MAC-Address Randomization
		5.3 Stationary Versus Nonstationary Devices
	6 Conclusions
	References
Author Index