BigchainDB
Abandoned Project Blockchain
BigchainDB is an open-source blockchain database. It is a NoSQL database that has blockchain properties such as immutability, decentralization and owner-controlled asset. Immutability is the property that once the data is stored in BigchainDB, it can’t be modified or erased. Decentralization means there is no single point of failure in the control and storage process of the data. The owner-controlled asset is the property that only the owner of the asset can transfer the asset. The database provides the user with Byzantine Fault Tolerance (BFT) with no more than one-third arbitrary node failures. There are two main layers in BigchainDB, the consensus layer based on Tendermint the and storage layer based on MongoDB.
History
The first version of BigchainDB was published in February 2016. However, there were many issues with the initial version. For example, the system was not Byzantine Fault tolerant, and there was a single point of failure in the underlying storage database and the system supported only one logical database, which means once got the control of the database the adversary could delete the whole database. BigchainDB 2.0 was published in 2018 and solved all the issues above.
The project was abandoned in 2018 after BigchainDB GmbH laid off the employees working on the DBMS. There has not been any significant update to the system's open-source repository since 2022.
Concurrency Control
Two-Phase Locking (Deadlock Prevention) Optimistic Concurrency Control (OCC)
The consensus layer is based on Tendermint. Tendermint uses LevelDB as blockchain storage. LevelDB uses Two-Phase Locking with Deadlock Prevention, see LevelDB for more details. The storage layer on each node is based on MongoDB. MongoDB uses Two-Phase Locking with Deadlock Prevention and Optimistic Concurrency Control, see MongoDB for more details.
Indexes
B+Tree Skip List Log-Structured Merge Tree
The consensus layer is based on LevelDB, see LevelDB for more details. The storage layer is based on MongoDB, see MongoDB for more details. The B+Tree is the index for main storage.
Isolation Levels
Read Uncommitted Snapshot Isolation
The consensus layer is based on LevelDB, see LevelDB for more details. The storage layer is based on MongoDB, see MongoDB for more details. LevelDB guarantees snapshot isolation for blockchain storage. MongoDB guarantees read uncommitted isolation level for main storage.
Logging
Logical Logging Physiological Logging
The consensus layer is based on LevelDB, see LevelDB for more details. The storage layer is based on MongoDB, see MongoDB for more details. MongoDB uses physiological logging, LevelDB uses logical logging.
Storage Model
N-ary Storage Model (Row/Record) Custom
The consensus layer is based on LevelDB, see LevelDB for more details. The storage layer is based on MongoDB, see MongoDB for more details. MongoDB supports custom storage model. LevelDB uses N-ary Storage Model.
System Architecture
BigchainDB 2.0 has two layers, the consensus layer, and the storage layer. Each node runs its own MongoDB database as the storage layer and uses Tendermint consensus protocol to communicate with each other. Each node maintains its own MongoDB database to store the structured data and handle queries, it also maintains a LevelDB key-value store to keep the blockchain and support the consensus protocol.
Each transaction is proposed by the proposer in each round, and the changes are not committed to the underlying MongoDB until it is settled on the blockchain. The Tendermint protocol can guarantee the BFT under at most one-third arbitrary node failures.
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Website
Source Code
https://github.com/bigchaindb/bigchaindb
Tech Docs
https://docs.bigchaindb.com/en/latest/
Developer
BigchainDB GmbH
Country of Origin
Start Year
2015
End Year
2022