See #5936 and #5938 for background. The plan was initially to have `DialNext()` and `EvictNext()` return a channel. However, implementing this became unnecessarily complicated and error-prone. As an example, the channel would be both consumed and populated (via method calls) by the same driving method (e.g. `Router.dialPeers()`) which could easily cause deadlocks where a method call blocked while sending on the channel that the caller itself was responsible for consuming (but couldn't since it was busy making the method call). It would also require a set of goroutines in the peer manager that would interact with the goroutines in the router in non-obvious ways, and fully populating the channel on startup could cause deadlocks with other startup tasks. Several issues like these made the solution hard to reason about. I therefore simply made `DialNext()` and `EvictNext()` block until the next peer was available, using internal triggers to wake these methods up in a non-blocking fashion when any relevant state changes occurred. This proved much simpler to reason about, since there are no goroutines in the peer manager (except for trivial retry timers), nor any blocking channel sends, and it instead relies entirely on the existing goroutine structure of the router for concurrency. This also happens to be the same pattern used by the `Transport.Accept()` API, following Go stdlib conventions, so all router goroutines end up using a consistent pattern as well.
Tendermint
Byzantine-Fault Tolerant State Machines. Or Blockchain, for short.
| Branch | Tests | Coverage | Linting |
|---|---|---|---|
| master |
Tendermint Core is Byzantine Fault Tolerant (BFT) middleware that takes a state transition machine - written in any programming language - and securely replicates it on many machines.
For protocol details, see the specification.
For detailed analysis of the consensus protocol, including safety and liveness proofs, see our recent paper, "The latest gossip on BFT consensus".
Releases
Please do not depend on master as your production branch. Use releases instead.
Tendermint is being used in production in both private and public environments, most notably the blockchains of the Cosmos Network. However, we are still making breaking changes to the protocol and the APIs and have not yet released v1.0. See below for more details about versioning.
In any case, if you intend to run Tendermint in production, we're happy to help. You can contact us over email or join the chat.
Security
To report a security vulnerability, see our bug bounty program. For examples of the kinds of bugs we're looking for, see our security policy.
We also maintain a dedicated mailing list for security updates. We will only ever use this mailing list to notify you of vulnerabilities and fixes in Tendermint Core. You can subscribe here.
Minimum requirements
| Requirement | Notes |
|---|---|
| Go version | Go1.15 or higher |
Documentation
Complete documentation can be found on the website.
Install
See the install instructions.
Quick Start
- Single node
- Local cluster using docker-compose
- Remote cluster using Terraform and Ansible
- Join the Cosmos testnet
Contributing
Please abide by the Code of Conduct in all interactions.
Before contributing to the project, please take a look at the contributing guidelines and the style guide. You may also find it helpful to read the specifications, watch the Developer Sessions, and familiarize yourself with our Architectural Decision Records.
Versioning
Semantic Versioning
Tendermint uses Semantic Versioning to determine when and how the version changes. According to SemVer, anything in the public API can change at any time before version 1.0.0
To provide some stability to Tendermint users in these 0.X.X days, the MINOR version is used to signal breaking changes across a subset of the total public API. This subset includes all interfaces exposed to other processes (cli, rpc, p2p, etc.), but does not include the Go APIs.
That said, breaking changes in the following packages will be documented in the CHANGELOG even if they don't lead to MINOR version bumps:
- crypto
- config
- libs
- bits
- bytes
- json
- log
- math
- net
- os
- protoio
- rand
- sync
- strings
- service
- node
- rpc/client
- types
Upgrades
In an effort to avoid accumulating technical debt prior to 1.0.0, we do not guarantee that breaking changes (ie. bumps in the MINOR version) will work with existing Tendermint blockchains. In these cases you will have to start a new blockchain, or write something custom to get the old data into the new chain. However, any bump in the PATCH version should be compatible with existing blockchain histories.
For more information on upgrading, see UPGRADING.md.
Supported Versions
Because we are a small core team, we only ship patch updates, including security updates, to the most recent minor release and the second-most recent minor release. Consequently, we strongly recommend keeping Tendermint up-to-date. Upgrading instructions can be found in UPGRADING.md.
Resources
Tendermint Core
For details about the blockchain data structures and the p2p protocols, see the Tendermint specification.
For details on using the software, see the documentation which is also hosted at: https://docs.tendermint.com/master/
Tools
Benchmarking is provided by tm-load-test.
Additional tooling can be found in /docs/tools.
Applications
- Cosmos SDK; a cryptocurrency application framework
- Ethermint; Ethereum on Tendermint
- Many more
Research
- The latest gossip on BFT consensus
- Master's Thesis on Tendermint
- Original Whitepaper: "Tendermint: Consensus Without Mining"
- Tendermint Core Blog
- Cosmos Blog
Join us!
Tendermint Core is maintained by Interchain GmbH. If you'd like to work full-time on Tendermint Core, we're hiring!
Funding for Tendermint Core development comes primarily from the Interchain Foundation, a Swiss non-profit. The Tendermint trademark is owned by Tendermint Inc., the for-profit entity that also maintains tendermint.com.
