Refine
Document Type
- Journal article (2)
- Conference proceeding (1)
Language
- English (3)
Has full text
- yes (3)
Is part of the Bibliography
- yes (3)
Institute
- Informatik (3)
Publisher
The manual deployment of applications distributed across the cloud, fog, and edge is error-prone and complex. TOSCA is a standard for modeling the deployment of cloud applications in a vendor-neutral and technology-independent manner that is also suitable for the fog and edge continuum. However, there exist various TOSCA orchestrators with different functionalities. Thus, selecting an appropriate TOSCA orchestrator requires technical expertise since all the available orchestrators must be analyzed regarding technical, functional, legal, and organizational requirements. In this paper, we tackle this issue and present a systematic technology review of TOSCA orchestrators. Our goal is to support project managers, developers, and researchers in selecting a suitable TOSCA orchestrator. For this, we select actively maintained general-purpose open-source TOSCA orchestrators. Moreover, we introduce the TOSCA Orchestrator Classification Framework and present a selection support system.
Blockchains have become increasingly important in recent years and have expanded their applicability to many domains beyond finance and cryptocurrencies. This adoption has particularly increased with the introduction of smart contracts, which are immutable, user-defined programs directly deployed on blockchain networks. However, many scenarios require business transactions to simultaneously access smart contracts on multiple, possibly heterogeneous blockchain networks while ensuring the atomicity and isolation of these transactions, which is not natively supported by current blockchain systems. Therefore, in this work, we introduce the Transactional Cross-Chain Smart Contract Invocation (TCCSCI) approach that supports such distributed business transactions while ensuring their global atomicity and serializability. The approach introduces the concept of Resource Manager Smart Contracts, and 2PC for Blockchains (2PC4BC), a client-driven Atomic Commit Protocol (ACP) specialized for blockchain-based distributed transactions. We validate our approach using a prototypical implementation, evaluate its introduced overhead, and prove its correctness.
The introduction of smart contracts has expanded the applicability of blockchains to many domains beyond finance and cryptocurrencies. Moreover, different blockchain technologies have evolved that target special requirements. As a result, in practice, often a combination of different blockchain systems is required to achieve an overall goal. However, due to the heterogeneity of blockchain protocols, the execution of distributed business transactions that span several blockchains leads to multiple interoperability and integration challenges. Therefore, in this article, we examine the domain of Cross-Chain Smart Contract Invocations (CCSCIs), which are distributed transactions that involve the invocation of smart contracts hosted on two or more blockchain systems. We conduct a systematic multi-vocal literature review to get an overview of the available CCSCI approaches. We select 20 formal literature studies and 13 high-quality gray literature studies, extract data from them, and analyze it to derive the CCSCI Classification Framework. With the help of the framework, we group the approaches into two categories and eight subcategories. The approaches differ in multiple characteristics, e.g., the mechanisms they follow, and the capabilities and transaction processing semantics they offer. Our analysis indicates that all approaches suffer from obstacles that complicate real-world adoption, such as the low support for handling heterogeneity and the need for trusted third parties.
