Key Terminology

VMware Blockchain terminologies and concepts are commonly used throughout the product documentation.

Authenticated Key-Value Ledger

To prove facts about smart contracts on the platform and allow access to a privacy-aware verifiable source of truth, VMware Blockchain stores the state of the blockchain in an authenticated key-value data structure. This data structure is part of the Replica nodes in the Replica network.

The authenticated data structure is implemented as a sparse Merkle tree where the application data keys are the tree leaves. Application data keys have metadata allowing the Replica Network to implement privacy controls.

Block

Shows results of the executed transactions committed to the blockchain ledger.

Blockchain

A data structure that holds a group of records. These groups of records create a block, and these blocks are linked using cryptography.

Each block contains a cryptographic hash of the previous block. The records are saved as a list of keys and their values, which comprise the state of the blockchain.

Client node

Allows sending requests to the Replica Network and receiving the results after running these requests.

BFT protocol

This protocol is the communication between the Replica nodes that allows them to synchronize. The nodes must agree on which requests are executed, the order of execution, and a process to maintain State Machine on all the Replica nodes.

The protocol can tolerate slower Replica nodes than others, disconnected or failing Replica nodes, and even malicious Replica nodes.

Daml

Daml (Digital Asset Modeling Language) is an open-source system for building full-stack smart contract-based distributed applications.

The core smart contract language is a purpose-built functional language specialized in describing composable distributed business workflows.

Daml Ledger API

Daml smart contracts are stored on a Ledger. To exercise choices on those smart contracts, create smart contracts, or read from the Daml Ledger, users use the Daml Ledger API.

Decentralized Applications (DApps)

An application that keeps some or all its state on the blockchain.

Full Copy Client Node

Stores the complete and unfiltered blockchain history since genesis.

Key Rotation

The operation of changing Replica or Client node keys is called key rotation. The key rotation operation does not require any downtime.

ObjectStore

An external storage device that stores the entire blockchain data, starting from the genesis block. The ObjectStore is the platform's source of truth.

Replica Node

Replica nodes participate in the BFT State Machine Replication protocol. Each Replica node has a Daml execution engine and stores its state in an authenticated key-value ledger.

Replica Network

A network consisting of Replica nodes that use an authenticated key-value storage and a deterministic State Machine to run smart contracts. The Replica nodes use the BFT protocol to create consensus and maintain the same state on all the nodes, even if some Replica nodes are down or malicious.

RocksDB

A local database that persists the authenticated key-value ledger on each Replica node.

Smart Contract Execution Engine

Interprets the Daml commands and provides results in a key-value format. Smart Contract Execution Engine is available in every Replica node in the blockchain.

Smart Contract

An application where the code and state are stored on the blockchain.

Transaction

Request sent from the Client node to the Replica Network to be executed, and the results persisted on the ledger.

VMware Blockchain

Distributed trust platform that enables business networks that might not necessarily trust one another, to share data or transact in a permissioned business network. The VMware Blockchain core natively supports pluggable State Machine Replication atop a BFT replication protocol.

VMware Blockchain enables the network to operate correctly even if a subset of Replica nodes behaves dishonestly. These guarantees do not depend on synchrony assumptions of the network, and a violation of message delivery deadlines might only result in a momentary lack of progress, not inconsistency or safety violations.

VMware Blockchain Orchestrator

A standalone virtual appliance (VApp) designed to streamline deployment operations on a private cloud environment. The VApp includes a CLI-based interface to configure the infrastructure and deployment parameters. The defined parameters automate several deployment tasks to simplify the deployment process.