Local Install
Last updated
Last updated
THIS GUIDE IS FOR TESTING PURPOSES ONLY
The below guide will instruct you on how to set up a Polygon Edge network on your local machine for testing and development purposes.
The procedure differs greatly from the way you would want to set up Polygon Edge network for a real use scenario on a cloud provider: Cloud Setup
Refer to Installation to install Polygon Edge.
In this guide, our goal is to establish a working polygon-edge blockchain network working with IBFT consensus protocol. The blockchain network will consist of 4 nodes of whom all 4 are validator nodes, and as such are eligible for both proposing block, and validating blocks that came from other proposers. All 4 nodes will run on the same machine, as the idea of this guide is to give you a fully functional IBFT cluster in the least amount of time.
To achieve that, we will guide you through 4 easy steps:
Initializing data directories will generate both the validator keys for each of the 4 nodes, and initialize empty blockchain data directories. The validator keys are important as we need to bootstrap the genesis block with the initial set of validators using these keys.
Preparing the connection string for the bootnode will be the vital information for every node we will run as to which node to connect to when starting for the first time.
Generating the genesis.json file will require as input both the validator keys generated in step 1 used for setting the initial validators of the network in the genesis block and the bootnode connection string from step 2.
Running all the nodes is the end goal of this guide and will be the last step we do, we will instruct the nodes which data directory to use and where to find the genesis.json which bootstraps the initial network state.
As all four nodes will be running on localhost, during the setup process it is expected that all the data directories for each of the nodes are in the same parent directory.
NUMBER OF VALIDATORS
There is no minimum to the number of nodes in a cluster, which means clusters with only 1 validator node are possible. Keep in mind that with a single node cluster, there is no crash tolerance and no BFT guarantee.
The minimum recommended number of nodes for achieving a BFT guarantee is 4 - since in a 4 node cluster, the failure of 1 node can be tolerated, with the remaining 3 functioning normally.
In order to get up and running with IBFT, you need to initialize the data folders, one for each node:
Each of these commands will print the validator key, bls public key and the node ID. You will need the Node ID of the first node for the next step.
The secrets output can be retrieved again, if needed.
For a node to successfully establish connectivity, it must know which bootnode server to connect to in order to gain information about all the remaining nodes on the network. The bootnode is sometimes also known as the rendezvous server in p2p jargon.
bootnode is not a special instance of the polygon-edge node. Every polygon-edge node can serve as a bootnode, but every polygon-edge node needs to have a set of bootnodes specified which will be contacted to provide information on how to connect with all remaining nodes in the network.
To create the connection string for specifying the bootnode, we will need to conform to the multiaddr format:
In this guide, we will treat the first and second nodes as the bootnodes for all other nodes. What will happen in this scenario is that nodes that connect to the node 1 or node 2 will get information on how to connect to one another through the mutually contacted bootnode.
YOU NEED TO SPECIFY AT LEAST ONE BOOTNODE TO START A NODE
At least one bootnode is required, so other nodes in the network can discover each other. More bootnodes are recommended, as they provide resilience to the network in case of outages. In this guide we will list two nodes, but this can be changed on the fly, with no impact on the validity of the genesis.json file.
Since we are running on localhost, it is safe to assume that the <ip_address> is 127.0.0.1.
For the <port> we will use 10001 since we will configure the libp2p server for node 1 to listen on this port later.
And lastly, we need the <node_id> which we can get from the output of the previously ran command polygon-edge secrets init --data-dir test-chain-1 command (which was used to generate keys and data directories for the node1)
After the assembly, the multiaddr connection string to the node 1 which we will use as the bootnode will look something like this (only the <node_id> which is at the end should be different):
Similarly, we construct the multiaddr for second bootnode as shown below
DNS HOSTNAMES INSTEAD OF IPS
Polygon Edge supports using DNS hostnames for the nodes configuration. This is a very helpful feature for cloud based deployments, as the node's ip may change due to various reasons.
The multiaddr format for the connection string while using DNS hostnames is as it follows: /dns4/sample.hostname.com/tcp/<port>/p2p/nodeid
What this command does:
The --ibft-validators-prefix-path sets the prefix folder path to the one specified which IBFT in Polygon Edge can use. This directory is used to house the consensus/ folder, where the validator's private key is kept. The validator's public key is needed in order to build the genesis file - the initial list of bootstrap nodes. This flag only makes sense when setting up the network on localhost, as in a real-world scenario we cannot expect all the nodes' data directories to be on the same filesystem from where we can easily read their public keys.
The --bootnode sets the address of the bootnode that will enable the nodes to find each other. We will use the multiaddr string of the node 1, as mentioned in step 2.
The result of this command is the genesis.json file which contains the genesis block of our new blockchain, with the predefined validator set and the configuration for which node to contact first in order to establish connectivity.
SWITCH TO ECDSA
BLS is the default validation mode of block headers. If you want your chain to run in ECDSA mode, you can use use the flag —ibft-validator-type, with the argument ecdsa:
PREMINING ACCOUNT BALANCES
You will probably want to set up your blockchain network with some addresses having "premined" balances.
To achieve this, pass as many --premine flags as you want per address that you want to be initialized with a certain balance on the blockchain.
For example, if we would like to premine 1000 ETH to address 0x3956E90e632AEbBF34DEB49b71c28A83Bc029862 in our genesis block, then we would need to supply the following argument:
Note that the premined amount is in WEI, not ETH.
SET THE BLOCK GAS LIMIT
The default gas limit for each block is 5242880. This value is written in the genesis file, but you may want to increase / decrease it.
To do so, you can use the flag --block-gas-limit followed by the desired value as shown below :
SET SYSTEM FILE DESCRIPTOR LIMIT
The default file descriptor limit ( maximum number of open files ) on some operating systems is pretty small. If the nodes are expected to have high throughput, you might consider increasing this limit on the OS level.
For Ubuntu distro the procedure is as follows ( if you're not using Ubuntu/Debian distro, check the official docs for your OS ) :
Check current os limits ( open files )
ulimit -a
Increase open files limit
Localy - affects only current session:
Globaly or per user ( add limits at the end of /etc/security/limits.conf file ) :
/etc/security/limits.conf
Optionaly, modify additional parameters, save the file and restart the system. After restart check file descriptor limit again. It should be set to the value you defined in limits.conf file.
Because we are attempting to run a Polygon Edge network consisting of 4 nodes all on the same machine, we need to take care to avoid port conflicts. This is why we will use the following reasoning for determining the listening ports of each server of a node:
10000 for the gRPC server of node 1, 20000 for the GRPC server of node 2, etc.
10001 for the libp2p server of node 1, 20001 for the libp2p server of node 2, etc.
10002 for the JSON-RPC server of node 1, 20002 for the JSON-RPC server of node 2, etc.
To run the first client (note the port 10001 since it was used as a part of the libp2p multiaddr in step 2 alongside node 1's Node ID):
To run the second client:
To run the third client:
To run the fourth client:
To briefly go over what has been done so far:
The directory for the client data has been specified to be ./test-chain-*
The GRPC servers have been started on ports 10000, 20000, 30000 and 40000, for each node respectively
The libp2p servers have been started on ports 10001, 20001, 30001 and 40001, for each node respectively
The JSON-RPC servers have been started on ports 10002, 20002, 30002 and 40002, for each node respectively
The seal flag means that the node which is being started is going to participate in block sealing
The chain flag specifies which genesis file should be used for chain configuration
The structure of the genesis file is covered in the CLI Commands section.
After running the previous commands, you have set up a 4 node Polygon Edge network, capable of sealing blocks and recovering from node failure.
START THE CLIENT USING CONFIG FILE
Instead of specifying all configuration parameters as CLI arguments, the Client can also be started using a config file by executing the following command:
Example:
Currently, we support yaml and json based configuration files, sample config files can be found here
STEPS TO RUN A NON-VALIDATOR NODE
A Non-validator will always sync the latest blocks received from the validator node, you can start a non-validator node by running the following command.
For example, you can add fifth Non-validator client by executing the following command :
SPECIFY THE PRICE LIMIT
A Polygon Edge node can be started with a set price limit for incoming transactions.
The unit for the price limit is wei.
Setting a price limit means that any transaction processed by the current node will need to have a gas price higher then the set price limit, otherwise it will not be included in a block.
Having the majority of nodes respect a certain price limit enforces the rule that transactions in the network cannot be below a certain price threshold.
The default value for the price limit is 0, meaning it is not enforced at all by default.
Example of using the --price-limit flag:
It is worth noting that price limits are enforced only on non-local transactions, meaning that the price limit does not apply to transactions added locally on the node.
WEBSOCKET URL
By default, when you run the Polygon Edge, it generates a WebSocket URL based on the chain location. The URL scheme wss:// is used for HTTPS links, and ws:// for HTTP.
Localhost WebSocket URL:
Please note that the port number depends on the chosen JSON-RPC port for the node.
Edgenet WebSocket URL:
Now that you've set up at least 1 running client, you can go ahead and interact with the blockchain using the account you premined above and by specifying the JSON-RPC URL to any of the 4 nodes:
Node 1: http://localhost:10002
Node 2: http://localhost:20002
Node 3: http://localhost:30002
Node 4: http://localhost:40002
Follow this guide to issue operator commands to the newly built cluster: How to query operator information (the GRPC ports for the cluster we have built are 10000/20000/30000/40000 for each node respectively)
