[![Solana crate](https://img.shields.io/crates/v/solana.svg)](https://crates.io/crates/solana) [![Solana documentation](https://docs.rs/solana/badge.svg)](https://docs.rs/solana) [![Build status](https://badge.buildkite.com/d4c4d7da9154e3a8fb7199325f430ccdb05be5fc1e92777e51.svg?branch=master)](https://solana-ci-gate.herokuapp.com/buildkite_public_log?https://buildkite.com/solana-labs/solana/builds/latest/master) [![codecov](https://codecov.io/gh/solana-labs/solana/branch/master/graph/badge.svg)](https://codecov.io/gh/solana-labs/solana) Blockchain, Rebuilt for Scale === Solana™ is a new blockchain architecture built from the ground up for scale. The architecture supports up to 710 thousand transactions per second on a gigabit network. Disclaimer === All claims, content, designs, algorithms, estimates, roadmaps, specifications, and performance measurements described in this project are done with the author's best effort. It is up to the reader to check and validate their accuracy and truthfulness. Furthermore nothing in this project constitutes a solicitation for investment. Introduction === It's possible for a centralized database to process 710,000 transactions per second on a standard gigabit network if the transactions are, on average, no more than 176 bytes. A centralized database can also replicate itself and maintain high availability without significantly compromising that transaction rate using the distributed system technique known as Optimistic Concurrency Control [\[H.T.Kung, J.T.Robinson (1981)\]](http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.65.4735). At Solana, we're demonstrating that these same theoretical limits apply just as well to blockchain on an adversarial network. The key ingredient? Finding a way to share time when nodes can't trust one-another. Once nodes can trust time, suddenly ~40 years of distributed systems research becomes applicable to blockchain! > Perhaps the most striking difference between algorithms obtained by our method and ones based upon timeout is that using timeout produces a traditional distributed algorithm in which the processes operate asynchronously, while our method produces a globally synchronous one in which every process does the same thing at (approximately) the same time. Our method seems to contradict the whole purpose of distributed processing, which is to permit different processes to operate independently and perform different functions. However, if a distributed system is really a single system, then the processes must be synchronized in some way. Conceptually, the easiest way to synchronize processes is to get them all to do the same thing at the same time. Therefore, our method is used to implement a kernel that performs the necessary synchronization--for example, making sure that two different processes do not try to modify a file at the same time. Processes might spend only a small fraction of their time executing the synchronizing kernel; the rest of the time, they can operate independently--e.g., accessing different files. This is an approach we have advocated even when fault-tolerance is not required. The method's basic simplicity makes it easier to understand the precise properties of a system, which is crucial if one is to know just how fault-tolerant the system is. [\[L.Lamport (1984)\]](http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.71.1078) Furthermore, and much to our surprise, it can be implemented using a mechanism that has existed in Bitcoin since day one. The Bitcoin feature is called nLocktime and it can be used to postdate transactions using block height instead of a timestamp. As a Bitcoin client, you'd use block height instead of a timestamp if you don't trust the network. Block height turns out to be an instance of what's being called a Verifiable Delay Function in cryptography circles. It's a cryptographically secure way to say time has passed. In Solana, we use a far more granular verifiable delay function, a SHA 256 hash chain, to checkpoint the ledger and coordinate consensus. With it, we implement Optimistic Concurrency Control and are now well en route towards that theoretical limit of 710,000 transactions per second. Testnet Demos === The Solana repo contains all the scripts you might need to spin up your own local testnet. Depending on what you're looking to achieve, you may want to run a different variation, as the full-fledged, performance-enhanced multinode testnet is considerably more complex to set up than a Rust-only, singlenode testnode. If you are looking to develop high-level features, such as experimenting with smart contracts, save yourself some setup headaches and stick to the Rust-only singlenode demo. If you're doing performance optimization of the transaction pipeline, consider the enhanced singlenode demo. If you're doing consensus work, you'll need at least a Rust-only multinode demo. If you want to reproduce our TPS metrics, run the enhanced multinode demo. For all four variations, you'd need the latest Rust toolchain and the Solana source code: First, install Rust's package manager Cargo. ```bash $ curl https://sh.rustup.rs -sSf | sh $ source $HOME/.cargo/env ``` Now checkout the code from github: ```bash $ git clone https://github.com/solana-labs/solana.git $ cd solana ``` The demo code is sometimes broken between releases as we add new low-level features, so if this is your first time running the demo, you'll improve your odds of success if you check out the [latest release](https://github.com/solana-labs/solana/releases) before proceeding: ```bash $ TAG=$(git describe --tags $(git rev-list --tags --max-count=1)) $ git checkout $TAG ``` Configuration Setup --- The network is initialized with a genesis ledger and leader/validator configuration files. These files can be generated by running the following script. ```bash $ ./multinode-demo/setup.sh ``` Drone --- In order for the leader, client and validators to work, we'll need to spin up a drone to give out some test tokens. The drone delivers Milton Friedman-style "air drops" (free tokens to requesting clients) to be used in test transactions. Start the drone on the leader node with: ```bash $ ./multinode-demo/drone.sh ``` Singlenode Testnet --- Before you start a fullnode, make sure you know the IP address of the machine you want to be the leader for the demo, and make sure that udp ports 8000-10000 are open on all the machines you want to test with. Now start the server in a separate shell: ```bash $ ./multinode-demo/leader.sh ``` Wait a few seconds for the server to initialize. It will print "leader ready..." when it's ready to receive transactions. The leader will request some tokens from the drone if it doesn't have any. The drone does not need to be running for subsequent leader starts. Multinode Testnet --- To run a multinode testnet, after starting a leader node, spin up some validator nodes in separate shells: ```bash $ ./multinode-demo/validator.sh ``` To run a performance-enhanced leader or validator (on Linux), [CUDA 10.0](https://developer.nvidia.com/cuda-downloads) must be installed on your system: ```bash $ ./fetch-perf-libs.sh $ SOLANA_CUDA=1 ./multinode-demo/leader.sh $ SOLANA_CUDA=1 ./multinode-demo/validator.sh ``` Testnet Client Demo --- Now that your singlenode or multinode testnet is up and running let's send it some transactions! In a separate shell start the client: ```bash $ ./multinode-demo/client.sh # runs against localhost by default ``` What just happened? The client demo spins up several threads to send 500,000 transactions to the testnet as quickly as it can. The client then pings the testnet periodically to see how many transactions it processed in that time. Take note that the demo intentionally floods the network with UDP packets, such that the network will almost certainly drop a bunch of them. This ensures the testnet has an opportunity to reach 710k TPS. The client demo completes after it has convinced itself the testnet won't process any additional transactions. You should see several TPS measurements printed to the screen. In the multinode variation, you'll see TPS measurements for each validator node as well. Public Testnet -------------- In this example the client connects to our public testnet. To run validators on the testnet you would need to open udp ports `8000-10000`. ```bash $ ./multinode-demo/client.sh --network $(dig +short testnet.solana.com):8001 --identity config-private/client-id.json --duration 60 ``` You can observe the effects of your client's transactions on our [dashboard](https://metrics.solana.com:3000/d/testnet/testnet-hud?orgId=2&from=now-30m&to=now&refresh=5s&var-testnet=testnet) Linux Snap --- A Linux [Snap](https://snapcraft.io/) is available, which can be used to easily get Solana running on supported Linux systems without building anything from source for evaluation. Note that CUDA is not supported by the Snap so performance will be limited. The `edge` Snap channel is updated daily with the latest development from the `master` branch. To install: ```bash $ sudo snap install solana --edge --devmode ``` Once installed the usual Solana programs will be available as `solona.*` instead of `solana-*`. For example, `solana.fullnode` instead of `solana-fullnode`. Update to the latest version at any time with: ```bash $ snap info solana $ sudo snap refresh solana --devmode ``` ### Daemon support The snap supports running a leader, validator or leader+drone node as a system daemon. Run `sudo snap get solana` to view the current daemon configuration. To view daemon logs: 1. Run `sudo snap logs -n=all solana` to view the daemon initialization log 2. Runtime logging can be found under `/var/snap/solana/current/leader/`, `/var/snap/solana/current/validator/`, or `/var/snap/solana/current/drone/` depending on which `mode=` was selected. Within each log directory the file `current` contains the latest log, and the files `*.s` (if present) contain older rotated logs. Disable the daemon at any time by running: ```bash $ sudo snap set solana mode= ``` Runtime configuration files for the daemon can be found in `/var/snap/solana/current/config`. #### Leader daemon ```bash $ sudo snap set solana mode=leader ``` `rsync` must be configured and running on the leader. 1. Ensure rsync is installed with `sudo apt-get -y install rsync` 2. Edit `/etc/rsyncd.conf` to include the following ``` [config] path = /var/snap/solana/current/config hosts allow = * read only = true ``` 3. Run `sudo systemctl enable rsync; sudo systemctl start rsync` 4. Test by running `rsync -Pzravv rsync:///config solana-config` from another machine. **If the leader is running on a cloud provider it may be necessary to configure the Firewall rules to permit ingress to port tcp:873, tcp:9900 and the port range udp:8000-udp:10000** To run both the Leader and Drone: ```bash $ sudo snap set solana mode=leader+drone ``` #### Validator daemon ```bash $ sudo snap set solana mode=validator ``` By default the validator will connect to **testnet.solana.com**, override the leader IP address by running: ```bash $ sudo snap set solana mode=validator leader-address=127.0.0.1 #<-- change IP address ``` It's assumed that the leader will be running `rsync` configured as described in the previous **Leader daemon** section. Developing === Architecture --- Before you jump into the code, review the [Solana Architecture](https://solana-labs.github.io/solana/). Building --- Install rustc, cargo and rustfmt: ```bash $ curl https://sh.rustup.rs -sSf | sh $ source $HOME/.cargo/env $ rustup component add rustfmt-preview ``` If your rustc version is lower than 1.26.1, please update it: ```bash $ rustup update ``` On Linux systems you may need to install libssl-dev, pkg-config, zlib1g-dev, etc. On Ubuntu: ```bash $ sudo apt-get install libssl-dev pkg-config zlib1g-dev llvm ``` Download the source code: ```bash $ git clone https://github.com/solana-labs/solana.git $ cd solana ``` Building the Solana book --- Install mdbook: ```bash cargo install mdbook ``` Run any Rust tests in the markdown: ```bash mdbook test ``` Render markdown as HTML: ```bash mdbook build ``` Render and view the book: ```bash mdbook build --open ``` Testing --- Run the test suite: ```bash $ cargo test ``` To emulate all the tests that will run on a Pull Request, run: ```bash $ ./ci/run-local.sh ``` Fullnode Debugging --- There are some useful debug messages in the code, you can enable them on a per-module and per-level basis. Before running a leader or validator set the normal RUST\_LOG environment variable. For example * To enable `info` everywhere and `debug` only in the solana::banking_stage module: ```bash $ export RUST_LOG=info,solana::banking_stage=debug ``` * To enable BPF program logging: ```bash $ export RUST_LOG=solana_bpf_loader ``` Generally we are using `debug` for infrequent debug messages, `trace` for potentially frequent messages and `info` for performance-related logging. You can also attach to a running process with GDB. The leader's process is named _solana-fullnode_: ```bash $ sudo gdb attach set logging on thread apply all bt ``` This will dump all the threads stack traces into gdb.txt Testnet Debugging --- We maintain several testnets: * `testnet` - public stable testnet accessible via testnet.solana.com, with an https proxy for web apps at api.testnet.solana.com. Runs 24/7 * `testnet-beta` - public beta channel testnet accessible via beta.testnet.solana.com. Runs 24/7 * `testnet-edge` - public edge channel testnet accessible via edge.testnet.solana.com. Runs 24/7 * `testnet-perf` - permissioned stable testnet running a 24/7 soak test * `testnet-beta-perf` - permissioned beta channel testnet running a multi-hour soak test weekday mornings * `testnet-edge-perf` - permissioned edge channel testnet running a multi-hour soak test weekday mornings ## Deploy process They are deployed with the `ci/testnet-manager.sh` script through a list of [scheduled buildkite jobs](https://buildkite.com/solana-labs/testnet-management/settings/schedules). Each testnet can be manually manipulated from buildkite as well. The `-perf` testnets use a release tarball while the non`-perf` builds use the snap build (we've observed that the snap build runs slower than a tarball but this has yet to be root caused). ## Where are the testnet logs? **TODO: This section is out of date and needs updating** Attach to the testnet first by running one of: ```bash $ net/gce.sh config testnet-solana-com $ net/gce.sh config master-testnet-solana-com $ net/gce.sh config perf-testnet-solana-com ``` Then run: ```bash $ net/ssh.sh ``` for log location details ## How do I reset the testnet? Manually trigger the [testnet-management](https://buildkite.com/solana-labs/testnet-management) pipeline and when prompted select the desired testnet ## How can I scale the tx generation rate? Increase the TX rate by increasing the number of cores on the client machine which is running `bench-tps` or run multiple clients. Decrease by lowering cores or using the rayon env variable `RAYON_NUM_THREADS=` ## How can I test a change on the testnet? Currently, a merged PR is the only way to test a change on the testnet. But you can run your own testnet using the scripts in the `net/` directory. ## Adjusting the number of clients or validators on the testnet Edit `ci/testnet-manager.sh` Benchmarking --- First install the nightly build of rustc. `cargo bench` requires unstable features: ```bash $ rustup install nightly ``` Run the benchmarks: ```bash $ cargo +nightly bench --features="unstable" ``` Release Process --- The release process for this project is described [here](rfcs/0005-branches-tags-and-channels.md). Code coverage --- To generate code coverage statistics, install cargo-cov. Note: the tool currently only works in Rust nightly. ```bash $ cargo +nightly install cargo-cov ``` Run cargo-cov and generate a report: ```bash $ cargo +nightly cov test $ cargo +nightly cov report --open ``` The coverage report will be written to `./target/cov/report/index.html` Why coverage? While most see coverage as a code quality metric, we see it primarily as a developer productivity metric. When a developer makes a change to the codebase, presumably it's a *solution* to some problem. Our unit-test suite is how we encode the set of *problems* the codebase solves. Running the test suite should indicate that your change didn't *infringe* on anyone else's solutions. Adding a test *protects* your solution from future changes. Say you don't understand why a line of code exists, try deleting it and running the unit-tests. The nearest test failure should tell you what problem was solved by that code. If no test fails, go ahead and submit a Pull Request that asks, "what problem is solved by this code?" On the other hand, if a test does fail and you can think of a better way to solve the same problem, a Pull Request with your solution would most certainly be welcome! Likewise, if rewriting a test can better communicate what code it's protecting, please send us that patch!