Cloud Setup
Last updated
Last updated
:::info This guide is for mainnet or testnet setups
The below guide will instruct you on how to set up a ZChains network on a cloud provider for a production setup of your testnet or mainnet.
If you would like to setup a ZChains network locally to quickly test the polygon-edge before doing a production-like setup, please refer to Local Setup :::
Refer to Installation to install ZChains.
Depending on your choice of cloud provider, you may set up connectivity and rules between the VMs using a firewall, security groups, or access control lists.
As the only part of the polygon-edge that needs to be exposed to other VMs is the libp2p server, simply allowing all communication between VMs on the default libp2p port 1478 is enough.
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. Each of the 4 nodes will run on their own VM, as the idea of this guide is to give you a fully functional ZChains network while keeping the validator keys private to ensure a trustless network setup.
To achieve that, we will guide you through 4 easy steps:
Take a look at the list of Requirements above
Generate the private keys for each of the validators, and initialize the data directory
Prepare the connection string for the bootnode to be put into the shared genesis.json
Create the genesis.json on your local machine, and send/transfer it to each of the nodes
Start all the nodes
:::info 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.
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To get up and running with ZChains, you need to initialize the data folders, on each node:
Each of these commands will print the node ID. You will need that information for the next step.
:::warning Keep your data directory to yourself!
The data directories generated above, besides initializing the directories for holding the blockchain state, will also generate your validator's private keys. This key should be kept as a secret, as stealing it would render somebody capable of impersonating you as the validator in the network! :::
For a node to successfully establish connectivity, it must know which bootnode server to connect 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 a Polygon Edge node. Every Polygon Edge node can serve as a bootnode and 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.
:::info 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. :::
As the first part of the multiaddr connection string is the <ip_address>, here you will need to enter the IP address as reachable by other nodes, depending on your setup this might be a private or a public IP address, not 127.0.0.1.
For the <port> we will use 1478, since it is the default libp2p port.
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 data-dir command (which was used to generate keys and data directories for the node 1)
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 multiaddr for the second bootnode as shown below
This step can be run on your local machine, but you will need the public validator keys for each of the 4 validators.
Validators can safely share the Public key (address) as displayed below in the output to their secrets init commands, so that you may securely generate the genesis.json with those validators in the initial validator set, identified by their public keys:
Given that you have received all 4 of the validators' public keys, you can run the following command to generate the genesis.json
What this command does:
The --ibft-validator sets the public key of the validator that should be included in the initial validator set in the genesis block. There can be many initial validators.
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, although you can add as many bootnodes as you want, as displayed above.
:::info 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.
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:::info 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 :
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:::info 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 )
Increase open files limit
Localy - affects only current session:
Globaly or per user ( add limits at the end of /etc/security/limits.conf file ) :
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. :::
After specifying the:
Public keys of the validators to be included in the genesis block as the validator set
Bootnode multiaddr connection strings
Premined accounts and balances to be included in the genesis block
and generating the genesis.json, you should copy it over to all of the VMs in the network. Depending on your setup you may copy/paste it, send it to the node operator, or simply SCP/FTP it over.
The structure of the genesis file is covered in the CLI Commands section.
:::note Networking on Cloud providers
Most cloud providers don't expose the IP addresses (especially public ones) as a direct network interface on your VM but rather setup an invisible NAT proxy.
To allow the nodes to connect to each other in this case you would need to listen on the 0.0.0.0 IP address to bind on all interfaces, but you would still need to specify the IP address or DNS address which other nodes can use to connect to your instance. This is achieved either by using the --nat or --dns argument where you can specify your external IP or DNS address respectively.
Example
The associated IP address that you wish to listen on is 192.0.2.1, but it is not directly bound to any of your network interfaces.
To allow the nodes to connect you would pass the following parameters:
polygon-edge ... --libp2p 0.0.0.0:10001 --nat 192.0.2.1
Or, if you wish to specify a DNS address dns/example.io, pass the following parameters:
polygon-edge ... --libp2p 0.0.0.0:10001 --dns dns/example.io
This would make your node listen on all interfaces, but also make it aware that the clients are connecting to it through the specified --nat or --dns address.
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To run the first client:
To run the second client:
To run the third client:
To run the fourth client:
After running the previous commands, you have set up a 4 node Polygon Edge network, capable of sealing blocks and recovering from node failure.
:::info 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 only support json based configuration file, sample config file can be found here
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:::info 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 :
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:::info Specify the price limit A Zchains e 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 than the set price limit, otherwise it will not be included into 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. :::
