Cardinal Metrics in Blockchain Functioning

Blockchain technology has been acquiring pace in deployments and implementations across globe vide association with large number of domains apart from widely known finance domain. These deployments are variegated in designs, have various architectures and possess functional differences. The commonality exists in deriving the benefits of blockchain technology through various technical variants of the widely known bitcoin blockchain architecture. Though still in evolving stage, the blockchain technology has been able to make an absolute mark in the industries, corporate and governance mechanisms to affirm that it’s part of a definite future. With devices estimate up to 50 billion in ecosystem of Internet-of-Things by 2025, the blockchain technology is soon going to be an integral part of future smart world. The deployment of any blockchain architecture might be able to accomplish the functional requirements as per design but the measurement of desired blockchain performance persists on a lot of parameters which need a balance and fine tuning established on purpose it has been designed for. In current times, transaction commit delays are being observed in bitcoin ecosystem. This paper identifies parameter effects on a bitcoin blockchain and measures the performance vide a bitcoin simulator effecting into tuning parameters like block size, blocks and number of nodes to analyze performance. The tuning effects into blockchain performance has been quantified, analyzed and discussed with focus on measuring and reducing the transaction propagation delays in a bitcoin environment. The paper concludes with heat map modeling plotted on Jupyter notebook with datasets derived.

Cross-chain Exchange by Transaction Dependence with Conditional Transaction

<div>Cross-chain exchange swaps assets among different blockchains, which facilitates cooperation among blockchains. A cross-chain exchange contains several transactions from different blockchains. It requires to synchronize asset transfers in those associated blockchains to avoid partial transfers. Current cross-chain methods are divided into two main types. One locks the assets first and transfers the frozen asset to receivers later. The second one is the two-phase or three-phase transaction commit protocol. Those methods require at least two steps, which makes those blockchains coherent to synchronize at different time(steps). Serialization is required as the second step has to wait for the completion of the first step, and even some steps in the same stage are required to be serialized. Meanwhile, their implements are either by smart contracts or special blockchain structures/roles. Smart contract based methods require to pre-deploy a smart contract and cannot change dynamically. Special structure or role-based methods force associated blockchains to have those special requirements. In this paper, we propose a new cross-chain exchange model based on the dependence of associated transactions, which is expressed inside a transaction and can change when sending transactions. It saves the step to lock the asset or perform a pre-commit and has no special requirements for blockchains or pre-deployment of smart contracts. The simulation results show the proposed model exchanges asset effectively among different blockchains.</div>

Cross-chain Exchange by Transaction Dependence with Conditional Transaction

<div>Cross-chain exchange swaps assets among different blockchains, which facilitates cooperation among blockchains. A cross-chain exchange contains several transactions from different blockchains. It requires to synchronize asset transfers in those associated blockchains to avoid partial transfers. Current cross-chain methods are divided into two main types. One locks the assets first and transfers the frozen asset to receivers later. The second one is the two-phase or three-phase transaction commit protocol. Those methods require at least two steps, which makes those blockchains coherent to synchronize at different time(steps). Serialization is required as the second step has to wait for the completion of the first step, and even some steps in the same stage are required to be serialized. Meanwhile, their implements are either by smart contracts or special blockchain structures/roles. Smart contract based methods require to pre-deploy a smart contract and cannot change dynamically. Special structure or role-based methods force associated blockchains to have those special requirements. In this paper, we propose a new cross-chain exchange model based on the dependence of associated transactions, which is expressed inside a transaction and can change when sending transactions. It saves the step to lock the asset or perform a pre-commit and has no special requirements for blockchains or pre-deployment of smart contracts. The simulation results show the proposed model exchanges asset effectively among different blockchains.</div>

LIFT- A Linear Two-Phase Commit Protocol

Two phase commit (2PC) protocol is used to coordinate transaction commitment in distributed database system. The 2PC protocol is further classified into linear and centralized versions. The linear version of 2PC i.e. L-2PC protocol runs serially whereas in the centralized version, the commit process allows every site involved in executing the transaction to prepare and commit in parallel. In past, very little efforts have been made to overcome the unfavourable message overhead, poor recovery process and some other problems associated with L-2PC protocol. This paper proposes a Linear and Fast-paced recovery centred Transaction commit (LIFT) protocol to improve the existing recovery mechanism of linear 2PC by allowing autonomy to the participating cohorts to inform the cohort-in-doubt about the distributed transaction’s state instead of always looking for coordinator’s stand. The performance results confirm that proposed protocol will be a better alternative.

A Survey on Efficient Concurrency Control Algorithm in Distributed Database Systems

Transaction commit protocols help in reaching an agreement among the participating nodes when a transaction has to be committed or aborted. To initiate an agreement each participating node is asked to vote its decision on the operations on its transactional fragment. The participating nodes can decide to either commit or abort an ongoing transaction. In case of a node failure, the active participants take essential steps such as running the termination protocol to preserve database correctness. This paper sought to investigate the current distributed databases commit protocols such as 2PC and 3PC in order to pin-point their shortcomings. For instance, 2PC suffers from blocking of participant site in case of coordinator failure and increased latency due to forced writes of logs. On its part, 3PC suffers more communication overhead due to extra pre-commit phase. Based on these setbacks, an efficient protocol is suggested towards the end of this paper that it believed to address some of the challenges such as blocking and extra message exchange between communicating nodes.

A Context-Driven Commit Protocol for Enhancing Transactional Services Performance in Pervasive Environments

The proposed techniques for wireless environments during the last decade have limited support for dynamically changing environments. Due to its nature, the mobile computing environment is extremely dynamic and subject to rapid and unpredictable changes. Similarly, the characteristics of mobile applications affect their transactional requirements. The challenge is to reflect on solutions offering more flexibility and adaptability. In this article, the contribution was focused mainly on the problem of atomic commit that ensures the atomicity property. The trail of adapting mobile transaction commit protocols to context changes has been explored. This has led to the formalization of a flexible transaction model CATSM that supports adaptable properties and a commit protocol CA-TCP that enables adaptation to application requirements and mobile context in terms of transactional properties and execution cost. An architecture based on the concept of adaptation policy has also been designed for the implementation of the proposed solution.