Copying of the node-info files moved out of Cordform and into NetworkParametersGenerator (which is now called NetworkBootstrapper). This class becomes an external tool to enable deployment of nodes in a test setup on a single filesystem.
4.8 KiB
Creating a Corda network
A Corda network consists of a number of machines running nodes. These nodes communicate using persistent protocols in order to create and validate transactions.
There are three broader categories of functionality one such node may have. These pieces of functionality are provided as services, and one node may run several of them.
- Notary: Nodes running a notary service witness state spends and have the final say in whether a transaction is a double-spend or not
- Oracle: Network services that link the ledger to the outside world by providing facts that affect the validity of transactions
- Regular node: All nodes have a vault and may start protocols communicating with other nodes, notaries and oracles and evolve their private ledger
Setting up your own network
Certificates
Every node in a given Corda network must have an identity certificate signed by the network's root CA. See permissioning
for more information.
Configuration
A node can be configured by adding/editing node.conf
in the node's directory. For details see corda-configuration-file
.
An example configuration:
example-code/src/main/resources/example-node.conf
The most important fields regarding network configuration are:
p2pAddress
: This specifies a host and port to which Artemis will bind for messaging with other nodes. Note that the address bound will NOT bemy-corda-node
, but rather::
(all addresses on all network interfaces). The hostname specified is the hostname that must be externally resolvable by other nodes in the network. In the above configuration this is the resolvable name of a machine in a VPN.rpcAddress
: The address to which Artemis will bind for RPC calls.webAddress
: The address the webserver should bind. Note that the port must be distinct from that ofp2pAddress
andrpcAddress
if they are on the same machine.
Bootstrapping the network
The nodes see each other using the network map. This is a collection of statically signed node-info files, one for each node in the network. Most production deployments will use a highly available, secure distribution of the network map via HTTP.
For test deployments where the nodes (at least initially) reside on the same filesystem, these node-info files can be placed directly in the node's additional-node-infos
directory from where the node will pick them up and store them in its local network map cache. The node generates its own node-info file on startup.
In addition to the network map, all the nodes on a network must use the same set of network parameters. These are a set of constants which guarantee interoperability between nodes. The HTTP network map distributes the network parameters which the node downloads automatically. In the absence of this the network parameters must be generated locally. This can be done with the network bootstrapper. This a tool that scans all the node configurations from a common directory to generate the network parameters file which is copied to the nodes' directories. It also copies each node's node-info file to every other node.
The bootstrapper tool can be built with the command:
gradlew buildBootstrapperJar
The resulting jar can be found in tools/bootstrapper/build/libs/
.
To use it, run the following command, specifying the root directory which hosts all the node directories as the argument:
java -jar network-bootstrapper.jar <nodes-root-dir>
Starting the nodes
You may now start the nodes in any order. You should see a banner, some log lines and eventually Node started up and registered
, indicating that the node is fully started.
In terms of process management there is no prescribed method. You may start the jars by hand or perhaps use systemd and friends.
Logging
Only a handful of important lines are printed to the console. For details/diagnosing problems check the logs.
Logging is standard log4j2 and may be configured accordingly. Logs are by default redirected to files in NODE_DIRECTORY/logs/
.
Connecting to the nodes
Once a node has started up successfully you may connect to it as a client to initiate protocols/query state etc. Depending on your network setup you may need to tunnel to do this remotely.
See the tutorial-clientrpc-api
on how to establish an RPC link.
Sidenote: A client is always associated with a single node with a single identity, which only sees their part of the ledger.