Distributed ledger data interactivity

Glossary

Term Definitions P2P network system Peer-to-peer network system, in which nodes can directly connect to each other and share resources Node Computer in a P2P network system, which can be a mobile phone, mining machine, server, etc. Transaction The process of sending data to a database or target node Sub-transaction Multiple data storage operations that may be included in a transaction Witness node Witness the transaction process, data, time, initiator, target object and other information, and package the witnessed transaction data to generate a block Storage node Node that stores the blocks generated by the witness node Directed acyclic graph (DAG) A data structure in which each block has multiple predecessor blocks and multiple successor blocks The block header contains the block information of the predecessor block ID, witness node signature, timestamp, unique identifier Nonce, data chain version, number of blocks and Merkle tree root The block body contains the block information of the transaction data nRW Random witness mechanismA consensus mechanism where the transaction initiating node randomly selects multiple witness nodes to witness the transactionQuery requestA user's request for query data on the distributed ledgerProxy node receives the user's query request and retrieves data from the distributed ledgerNode tree structureA data structure with high fault tolerance and load balancing, used to maintain the root node of the P2P network systemThe top-level node of the tree structureParent nodeThe parent node of a node in the tree structureThe child nodeThe subordinate node of a node in the tree structureExtensible maintenance programA program used to optimize the P2P network system structure, query latency, and query result deduplication verificationFault-tolerant maintenance programA program used to maintain the connectivity of the P2P network system when a node failsActive ListContains a list of nodes that establish a TCP connection with the current nodeEager ListPart of the Active List, containing nodes used to transmit messagesLazy ListPart of the Active List, containing nodes used to transmit message digests or message IDs, used for optimization and fault tolerancePassive ListContains a list of random nodes on the network, used to replace disconnected nodes in the Active ListHyparViewA P2P network topology structure used to build and maintain the P2P network systemKAD (Kademlia)A distributed hash table algorithm used to initialize the node's neighbor node listIHAVE messageMessage containing message ID, used for scalable maintenance programNORMAL messageMessage used to transmit query request or query resultGRAFT messageMessage used to repair P2P network systemTTL (Time to Live)Message lifetime, used to control the propagation range of messages in the networkData deduplication rateIndicator used to measure the deduplication effect of proxy node query resultsQuery latencyThe time from the user initiating the query request to receiving the query resultShort answer question

Please briefly describe the principle of data tamper-proof in distributed ledgers. Answer: Distributed ledgers use multi-node storage and consensus mechanisms to ensure data tamper-proof. Each transaction is witnessed by multiple witness nodes and blocks are generated. Blocks are stored in multiple random storage nodes to form a DAG structure. Tamperers need to find all related blocks and modify them, which is extremely difficult.

Please explain the working principle of the nRW random witness mechanism. Answer: In the nRW random witness mechanism, the transaction initiating node randomly selects multiple witness nodes to witness the transaction. Each witness node independently packages the transaction to generate a block, and randomly selects multiple storage nodes to store the block. This random selection and decentralization method increases the difficulty of tampering.

Please briefly describe the query request processing flow in the distributed ledger. Answer: The user sends the query request to the proxy node, and the proxy node broadcasts the request to all nodes in the P2P network system. Each node retrieves the local database and returns the result to the parent node, the parent node deduplicates and verifies the result, and finally the root node returns the final result to the user.

Please explain the role of the tree structure in the distributed ledger query process. Answer: The tree structure is used to maintain the P2P network system, and realizes the broadcast of query requests and the aggregation of query results through message passing between parent and child nodes. The high fault tolerance and load balancing of the tree structure ensure query efficiency and reliability.

Please explain the role of Eager List, Lazy List and Passive List. Answer: Eager List stores nodes used to transmit messages, Lazy List stores nodes used to transmit message digests or message IDs for optimization and fault tolerance, and Passive List stores random nodes on the network to replace disconnected nodes in Active List.

Please briefly describe the application of HyparView in distributed ledgers. Answer: HyparView is used to build and maintain P2P network systems, and ensures the connectivity of the network by maintaining the neighbor node list of the node.

Please explain the role of the KAD algorithm in the distributed ledger. Answer: The KAD algorithm is used to initialize the neighbor node list of the node, and measures the association between nodes according to the XOR distance of the node ID, so as to achieve efficient node search.

Please explain the role of IHAVE messages, NORMAL messages, and GRAFT messages. Answer: IHAVE messages are used for scalable maintenance programs, NORMAL messages are used to transmit query requests or query results, and GRAFT messages are used to repair P2P network systems.

Please explain the meaning of data deduplication rate. Answer: The data deduplication rate is used to measure the deduplication effect of the query results of the proxy node. The higher the deduplication rate, the lower the processing load of the proxy node.

Please explain the scalability of the distributed ledger query system. Answer: The distributed ledger query system can increase the processing capacity by adding nodes and adjusting the out-degree of nodes to cope with the growing amount of data and query requests.