Below is a sketch of some of the things we plan to do in upcoming releases of BigchainDB Server (and associated software), i.e. in the near term. It is, of course, subject to change. If you don't see an important feature listed here, please read about how to request a feature in our docs on Contributing to BigchainDB.
The main change in BigchainDB 2.0 (from 1.3) is that consensus, replication and sync are done using Tendermint. That means that BigchainDB 2.0 is Byzantine Fault Tolerant (BFT).
Starting with BigchainDB 2.0, we commit to making it possible to migrate to the next version without loss of data. We will provide documentation and tools to help with migration. This is needed by users who are going into production.
Done in BigchainDB 2.0 Alpha, Released on April 3, 2018
- Finish HTTP API changes
- Simplify & automate the production deployment process
- Consolidate the proposal system (especially COSS)
- Change the allowed transaction version number from "1.0" to "2.0"
- BigchainDB Server CLI updates (not the client-side CLI: deprecate that)
- Compute an app hash for Tendermint (in a dumb way that works).
- Standard process to set up a local node for development & testing, using Docker Compose.
- Set up a network for the AE team to do some performance tests.
bigchaindb upsert-validatorsubcommand to add/change/remove a validator at run time, "insecure" way.
- The Events API ane Events Plugin API: update code & docs.
Done in BigchainDB 2.0 Alpha 2, Released on April 18, 2018
- Implement BEP-8.
- Provide more informative HTTP responses when posting transactions.
Done in BigchainDB 2.0 Alpha 3, Released on May 3, 2018
- Fix all priority-0 bugs, such as issue #2182.
- Integrate the latest verson of Tendermint. This means upgrading the ABCI server software used by BigchainDB (py-abci).
- In our production deployment template, combine Tendermint and BigchainDB inside one Kubernetes StatefulSet (a kind of pod, one with persistent state).
- Documentation about how a node operator can expose the full power of MongoDB to users.
Done in BigchainDB 2.0 Beta 1, Released on June 1, 2018
- Have a second, internal test network, where each node is operated by a different BigchainDB employee.
- Update the Ansible & Vagrant deployment tooling.
- Remove some dead code, e.g. the code for RethinkDB support, and the "pipelines" code.
Done in BigchainDB 2.0 Beta 2, Released on July 16, 2018
- The test networks have run without issue for weeks.
- Performance optimization by fixing the MongoDB index on transaction id.
- New BigchainDB configuration settings: Tendermint host and port.
- Made changes to BigchainDB to keep up with changes in Tendermint.
- Remove a lot of dead code, e.g. the code for voting & blocks.
Done in BigchainDB 2.0 Beta 3, Released on July 18, 2018
Fixed a bug in transaction validation.
Done in BigchainDB 2.0 Beta 4, Released on July 30, 2018
- Implement a clean shutdown procedure for BigchainDB.
- Monit script to manage both BigchainDB and Tendermint as a single service unit.
- Some tests cleanup.
- Implement BEP-14 in the Python driver.
Done in BigchainDB 2.0 Beta 5, Released on August 1, 2018
- Updated the supported Tendermint version to Tendermint 0.22.8.
- Fixed a bug.
Done in BigchainDB 2.0 Beta 6, Released on September 17, 2018
- Have a way to add/remove/update a validator at run-time.
- Create and run more performance tests (benchmarks) and stress tests. Publish all testing software and test results.
- A single Docker container containing BigchainDB, Tendermint and MongoDB.
- Tests cleanup.
- Add support for MongoDB authentication by username & password.
Goals for the Final Stable Release of BigchainDB 2.0
There's a loose collection of some BigchainDB 2.0 "TODO" items in the GitHub organization project board named BigchainDB 2.0 TODO: https://github.com/orgs/bigchaindb/projects/5
- Migration to future versions should be possible: write about how to do that in various cases. See the explanation of what that means in the first paragraph of this section. See BEP-42. Implement one of the options in BEP-42 and test that implementation.
- Ongoing: Make changes to keep up with changes in Tendermint before the release of Tendermint 1.0. See the tendermint/tendermint "launch" milestone
- (Maybe) Change the Dockerfile to use the Alpine (minimal) base image.
Some Goals for BigchainDB 2.1 and Beyond
Short-Term Goals - Low-Hanging Fruits
These are features which are solving a very specific problem. These features, while not scoped, are expected to be small to medium in implementation complexity.
- Better node deployment and setup process.
- Data privacy features with (optional) support for encryption using a more modular plugins-based approach.
- node level encryption
- peer to peer encryption on same node - needs KMS
- Plugin architecture for transaction validation. Refactor the tx code: BEP-9. Generalize the codebase. Dynamic loading of plugins using validator election.
- Defining scale-up and scale-out strategies for nodes in a network expecting larger loads. As a first step, running load tests to find infrastructure limit.
- Propose a new transaction model that:
- doesn't use crypto-conditions
- supports the signature scheme used by Ethereum, i.e. secp256k1 keys
- Support for key management solution for easier access and better integration.
- Ability to delete past transactions. This is an approach to GDPR compliance (e.g. the "right to be forgotten"). If a user has access to keys, let them instigate deletion, otherwise the nodes must vote on deletion. The modified blockchain must still be valid, somehow (when replayed).
- Scale-up and scale-out strategy. Documentation to educate users why there is a limit. Add another local mempool for capacity (i.e. to moderate the load on the existing mempool).
- Privacy using zero-knowledge proofs.
Medium-Term Goals - Journey Projects
These are typically a collection of features which are solving a much broader set of problems. These features can result in several BigchainDB Enhancement Proposals (BEPs) during scoping and are expected to be medium to large in implementation complexity.
- Support smart contracts (and create new marketing channels) via:
- Support for light clients.
- Allow network admins and node admins to define their own MongoDB collections and indexes for better control over schemas.
- System-level and user-level transactions.
Other Goals for BigchainDB 2.1 and Beyond
- Integration with Polkadot.
- Native support for CRUD/CRAB.
- Have only one backend to store all data, i.e. don't store all data in both MongoDB and LevelDB.
- Document how to run a production validator.
- Recommended configuration settings.
- Sentry nodes for public networks, to hide the IP addresses of validators; see issue https://github.com/bigchaindb/bigchaindb/issues/2333).
- More performance optimizations, e.g. by removing unneeded deepcopy operations.
- New network-wide consistent max-transaction-size parameter. See https://github.com/bigchaindb/BEPs/issues/83
- New way to compute the app hash based on the UTXO set, including an efficient way to update the Merkle tree used to compute the app hash from the UTXO set.
- Support hashlock conditions (securely: need to make sure that every transaction is still signed by a client)
- Support timelock conditions
- Test what happens when a node runs out of memory or hard drive space. For example, what happens when there's no more space for MongoDB to write a block?
- Stop using 3scale (currently used by the BigchainDB Testnet).
- Make it possible to run a public BigchainDB network where anyone can add a node (without permission).