Casper is the blockchain platform purpose-built to scale opportunity for everyone. Building toward blockchain’s next frontier, Casper is designed for real-world applications without sacrificing usability, cost, decentralization, or security. It removes the barriers that prevent mainstream blockchain adoption by making blockchain friendly to use, open to the world, and future-proof to support innovations today and tomorrow. Guided by open-source principles and built from the ground up to empower individuals, the team seeks to provide an equitable foundation made for long-lasting impact. Read more about our mission at: https://casper.network/network/casper-association
The status on development is reported during the Community calls and is found here
The Casper MainNet is live.
- Writing Smart Contracts
- Rust Smart Contract SDK
- Rust Smart Contract API Docs
- AssemblyScript Smart Contract API
This is the core application for the Casper blockchain.
- CMake 3.1.4 or greater
- Rust
- libssl-dev
- pkg-config
- gcc
- g++
- recommended wasm-strip (used to reduce the size of compiled Wasm)
Before building a node, prepare your Rust build environment:
make setup-rs
The node software can be compiled afterwards:
cargo build -p casper-node --release
The result will be a casper-node binary found in target/release. Copy this somewhere into your
PATH, or substitute target/release/casper-node for casper-node in all examples below.
To run a validator node you will need to specify a config file and launch the validator subcommand, for example
casper-node validator /etc/casper-node/config.toml
The node ships with an example configuration file that should be setup first. There is also a template for a local chainspec in the same folder.
For launching, the following configuration values must be properly set:
| Setting | Description |
|---|---|
network.known_addresses |
Must refer to public listening addresses of one or more currently-running nodes. If the node cannot connect to any of these addresses, it will panic. The node can be run with this referring to its own address, but it will be equivalent to specifying an empty list for known_addresses - i.e. the node will run and listen, but will be reliant on other nodes connecting to it in order to join the network. This would be normal for the very first node of a network, but all subsequent nodes should normally specify that first node's public listening address as their known_addresses. |
The node will not run properly without another node to connect to. It is recommended that multiple nodes are run.
There is a tool which automates the process of running multiple nodes on a single machine.
Note that running multiple nodes on a single machine is normally only recommended for test purposes.
In general nodes are configured through a configuration file, typically named config.toml. This
file may reference other files or locations through relative paths. When it does, note that all
paths that are not absolute will be resolved relative to config.toml directory.
Some environments may call for overriding options through the environment. In this
scenario, the NODE_CONFIG environment variable can be used. For example:
alternatively expressed as
export NODE_CONFIG=consensus.secret_key_path=secret_keys/node-1.pem;network.known_addresses=[1.2.3.4:34553, 200.201.203.204:34553]
casper-node validator /etc/casper-node/config.toml
Note how the semicolon is used to separate configuration overrides here.
To set the threshold at which a warn-level log message is generated for a long-running reactor event, use the env var
CL_EVENT_MAX_MICROSECS. For example, to set the threshold to 1 millisecond:
CL_EVENT_MAX_MICROSECS=1000
To set the threshold at which a queue dump will occur, use the env var CL_MEM_DUMP_THRESHOLD_MB. When the process reaches this level of memory allocation a dump will occur, but this will only occur once. Queue dumps can be found in /tmp once they are complete. For example, to set the threshold to 16000 megabytes:
CL_MEM_DUMP_THRESHOLD_MB=16000
Logging can be enabled by setting the environment variable RUST_LOG. This can be set to one of the following levels,
from lowest priority to highest: trace, debug, info, warn, error:
RUST_LOG=info cargo run --release -- validator resources/local/config.toml
If the environment variable is unset, it is equivalent to setting RUST_LOG=error.
A typical log message will look like:
Jun 09 01:40:17.315 INFO [casper_node::components::rpc_server rpc_server.rs:127] starting HTTP server; server_addr=127.0.0.1:7777
This is comprised of the following parts:
- timestamp
- log level
- full module path (not to be confused with filesystem path) of the source of the message
- filename and line number of the source of the message
- message
RUST_LOG can be set to enable varying levels for different modules. Simply set it to a comma-separated list of
module-path=level, where the module path is as shown above in the typical log message, with the end truncated to suit.
For example, to enable trace level logging for the small_network module in components, info level for all other
modules in components, and warn level for the remaining codebase:
RUST_LOG=casper_node::components::small=trace,casper_node::comp=info,warn
Some additional debug functionality is available, mainly allowed for inspections of the internal event queue.
The event queue can be dumped by sending a SIGUSR1 to the running node process, e.g. if the node's process ID was $NODE_PID:
kill -USR1 $NODE_PIDThis will create a queue_dump.json in the working directory of the node. A tool like jq can then be used to format and display it:
$ jq < queue_dump.json
{
"NetworkIncoming": [],
"Network": [],
"Regular": [
"AddressGossiper"
],
"Api": []
}Dump the type of events:
jq 'map_values( map(keys[0] | {"type": ., weight: 1})| group_by(.type) | map ([.[0].type,(.|length)]) | map({(.[0]): .[1]}) )' queue_dump.jsonCount number of events in each queue:
jq 'map_values(map(keys[0]))' queue_dump.jsonSee the client README.
To support upgrades with a network, the casper-node is installed using scripts distributed with the casper-node-launcher.