Understanding replication in databases and distributed systems

2011

The necessity of ever-increasing use of distributed data in computer networks is obvious for all. One technique that is performed on the distributed data for increasing of efficiency and reliablity is data rplication. In this paper, after introducing this technique and its advantages, we will examine some dynamic data replication. We will examine their characteristies for some overus scenario and the we will propose some suggestion for their improvement.

International Journal of Current Microbiology and Applied Sciences, 2019

In database replication, primary-copy systems sort out easily the problem of keeping replicate data consistent by allowing only updates at the primary copy. While this kind of systems are very efficient with workloads dominated by read-only transactions, the update-everywhere approach is more suitable for heavy update loads. However, this approach adds a significant overload when working with readonly transactions. We propose a new database replication paradigm, halfway between primary-copy and update-everywhere approaches, which permits improving system performance adapting its configuration to the workload, thanks to a deterministic database replication protocol which ensures that broadcast writesets are always going to be committed.

Bokhari, Syed Mohtashim Abbas, and Oliver Theel. "A flexible hybrid approach to data replication in distributed systems." Intelligent Computing: Proceedings of the 2020 Computing Conference, Volume 1. Springer International Publishing, 2020, 2020

Data replication plays a very important role in distributed computing because a single replica is prone to failure, which is devastating for the availability of the access operations. High availability and low cost for the access operations as well as maintaining data consistency are major challenges for reliable services. Since failures are often inevitable in a distributed paradigm, thereby greatly affecting the availability of services. Data replication mitigates such failures by masking them and makes the system more fault-tolerant. It is the concept by which highly available data access operations can be realized while the cost should be not too high either. There are various state-of-the-art data replication strategies, but there exist infinitely many scenarios which demand designing new data replication strategies. In this regard, this work focuses on this problem and proposes a holistic hybrid approach towards data replication based on voting structures.

Proceedings of the 2009 EDBT/ICDT Workshops on - EDBT/ICDT '09, 2009

In distributed systems, replication is used for ensuring availability and increasing performances. However, the heavy workload of distributed systems such as web2.0 applications or Global Distribution Systems, limits the benefit of replication if its degree (i.e., the number of replicas) is not controlled. Since every replica must perform all updates eventually, there is a point beyond which adding more replicas does not increase the throughput, because every replica is saturated by applying updates. Moreover, if the replication degree exceeds the optimal threshold, the useless replica would generate an overhead due to extra communication messages. In this paper, we propose a suitable replication management solution in order to reduce useless replicas. To this end, we define two mathematical models which approximate the appropriate number of replicas to achieve a given level of performance. Moreover, we demonstrate the feasibility of our replication management model through simulation. The results expose the effectiveness of our models and their accuracy.

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2010

Over this six-year journey, many people have crossed my path. New friendships have been born and others have become stronger. So I want you to know that this work would not be possible without your support. Most importantly, I want you to know that these years were crucial for me not only due to the knowledge that I have acquired with your help but also due to the life experience that they have represented. I have no words to thank you for this opportunity. I want to thank everybody from the GSD for the wonderful work environment, in particular, Luí Soares, José Orlando, and António Sousa for the support when needed and the insightful discussions. Thank you, Rui, for this opportunity and for your friendship and advice.

Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems - PODS '97, 1997

The issue of data replication is considered in the context of a restricted system model motivated by certain distributed data-warehousing applications. A new replica management protocol is defined for this model in which gIobaI serializability is ensured, while message overhead and deadlock frequency are less than in previously published work. The advantages of the protocol arise from its use of a lazy approach to update of secondary copies of replicated data and the use of a new concept, virtual sites, to reduce the potential for conflict among global transactions.

Bioscience Biotechnology Research Communications

Replication structures are research areas of all distributed databases. We provide an overview in this paper for comparing the replication strategies for such database systems. The problems considered are data consistency and scalability. These problems preserve continuity with all its replicas spread across multiple nodes between the actual real time event in the external world and the images. A framework for a replicated real time database is discussed and all time constraints are preserved. To broaden the concept of modeling a large database, a general outline is presented which aims to improve the consistency of the data.

International Journal on Information Theory, 2014

In this paper, a review for consistency of data replication protocols has been investigated. A brief deliberation about consistency models in data replication is shown. Also we debate on propagation techniques such as eager and lazy propagation. Differences of replication protocols from consistency view point are studied. Also the advantages and disadvantages of the replication protocols are shown. We advent into essential technical details and positive comparisons, in order to determine their respective contributions as well as restrictions are made. Finally, some literature research strategies in replication and consistency techniques are reviewed.

2007 International Multi-Conference on Computing in the Global Information Technology (ICCGI'07), 2007

Our approach uses replication and guarantees that all processing replicas achieve state consistency, both in the absence of failures and after a failure heals. We achieve consistency in the former case by defining a data-serializing operator that ensures that the order of tuples to a downstream operator is the same at all the replicas. To achieve consistency after a failure heals, we develop approaches based on checkpoint/redo and undo/redo techniques.