Byzantine agreement problem in distributed system ppt
Distributed systems are computer systems that consist of multiple nodes or computers that communicate and coordinate with each other to perform a task. These systems are essential in today`s world as they provide the ability to distribute workloads and increase system responsiveness. However, one of the most significant challenges faced by distributed systems is achieving agreement among the nodes.
The Byzantine agreement problem is a challenge that arises in distributed systems when some of the nodes fail or behave maliciously. The term `Byzantine` is used to describe a node that behaves unexpectedly, and this may include sending incorrect information or withholding information altogether. The Byzantine agreement problem aims to find a way to achieve consensus among the nodes, even in the presence of Byzantine nodes.
One of the most popular algorithms used to solve the Byzantine agreement problem in a distributed system is the Byzantine Fault Tolerance (BFT) algorithm. This algorithm was first introduced in the paper „The Byzantine Generals Problem“ by Leslie Lamport, Robert Shostak, and Marshall Pease in 1982. The BFT algorithm is a protocol that allows a group of distributed nodes to agree on a single decision despite the presence of Byzantine nodes.
The BFT algorithm works by dividing the nodes into three groups: primary, backup, and non-replica nodes. The primary nodes are responsible for initiating the agreement and proposing a decision. The backup nodes are designed to ensure the consensus is achieved even if the primary nodes fail or behave maliciously. The non-replica nodes act as observers and do not participate in the consensus process.
The BFT algorithm works by having each node send a message to its neighbor nodes to propose a decision. Each neighbor node then sends the message to its neighbor nodes, and this process continues until eventually, all nodes receive the message. The nodes then send messages to each other to vote on the decision. Once the nodes have received the majority of votes, they agree on the proposed decision.
In conclusion, the Byzantine agreement problem remains a significant challenge in distributed systems. The BFT algorithm provides a solution to the problem by allowing nodes to reach a consensus even in the presence of Byzantine nodes. By using this algorithm, distributed systems can ensure reliability and consistency in their operations.