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How to Set Up a BigchainDB Network
Note 1: These instructions will also work for a "network" with only one node.
Note 2: You might not need to set up your own network yet. You should start by creating a proof-of-concept app that writes to the BigchainDB Testnet, and if that goes well, then you can look into setting up your own network.
Note 3: If you want to set up a node or network so that you can contribute to developing and testing the BigchainDB code, then see the docs about contributing to BigchainDB.
The process to create a network is both social and technical: social because someone (that we will call Coordinator) needs to find at least three other Members willing to join the network, and coordinate the effort; technical because each member of the network needs to set up a machine running BigchainDB. (Note: a Coordinator is a Member as well.)
A BigchainDB Network (or just Network) is a set of 4 or more BigchainDB Nodes (or Nodes). Every Node is independently managed by a Member, and runs an instance of the BigchainDB Server software. At the Genesis of a Network, there MUST be at least 4 Nodes ready to connect. After the Genesis, a Network can dynamically add new Nodes or remove old Nodes.
A Network will stop working if more than one third of the Nodes are down or faulty in any way. The bigger a Network, the more failures it can handle. A Network of size 4 can tolerate only 1 failure, so if 3 out of 4 Nodes are online, everything will work as expected. Eventually, the Node that was offline will automatically sync with the others.
Before We Start
This tutorial assumes you have basic knowledge on how to manage a GNU/Linux machine. The commands are tailored for an up-to-date Debian-like distribution. (We use an Ubuntu 18.04 LTS Virtual Machine on Microsoft Azure.) If you are on a different Linux distribution then you might need to adapt the names of the packages installed.
We don't make any assumptions about where you run the Node. You can run BigchainDB Server on a Virtual Machine on the cloud, on a machine in your data center, or even on a Raspberry Pi. Just make sure that your Node is reachable by the other Nodes. Here's a non-exhaustive list of examples:
- good: all Nodes running in the cloud using public IPs.
- bad: some Nodes running in the cloud using public IPs, some Nodes in a private network.
- good: all Nodes running in a private network.
The rule of thumb is: if Nodes can ping each other, then you are good to go.
The next sections are labelled with Member or Coordinator, depending on who should follow the instructions. Remember, a Coordinator is also a Member.
Member: Set Up a Node
Every Member in the Network must set up its own Node. The process consists of installing three components, BigchainDB Server, Tendermint Core, and MongoDB, and configuring the firewall.
Important note on security: it's up to the Member to harden their system.
Install the Required Software
Make sure your system is up to date.
sudo apt update
sudo apt full-upgrade
Install BigchainDB Server
BigchainDB Server requires Python 3.6+, so make sure your system has it. Install the required packages:
sudo apt install -y python3-pip libssl-dev
Now install the latest version of BigchainDB. Check the project page on PyPI for the last version (which was 2.0.0a6 at the time of writing) and install it:
sudo pip3 install bigchaindb==2.0.0a6
Check that you installed the correct version of BigchainDB Server using bigchaindb --version.
Install (and Start) MongoDB
Install a recent version of MongoDB. BigchainDB Server requires version 3.4 or newer.
sudo apt install mongodb
If you install MongoDB using the above command (which installs the mongodb package), it also configures MongoDB, starts MongoDB (in the background), and installs a MongoDB startup script (so that MongoDB will be started automatically when the machine is restarted).
Note: The mongodb package is not the official MongoDB package from MongoDB the company. If you want to install the official MongoDB package, please see the MongoDB documentation. Note that installing the official package doesn't also start MongoDB.
Install Tendermint
Install a recent version of Tendermint. BigchainDB Server requires version 0.19.9 or newer.
sudo apt install -y unzip
wget https://github.com/tendermint/tendermint/releases/download/v0.19.9/tendermint_0.19.9_linux_amd64.zip
unzip tendermint_0.19.9_linux_amd64.zip
rm tendermint_0.19.9_linux_amd64.zip
sudo mv tendermint /usr/local/bin
Set Up the Firewall
Make sure to accept inbound connections on ports 9984, 9985, and 26656. You might also want to add port 22 so that you can continue to access the machine via SSH.
sudo ufw allow 22/tcp
sudo ufw allow 9984/tcp
sudo ufw allow 9985/tcp
sudo ufw allow 26656/tcp
sudo ufw enable
Some cloud providers, like Microsoft Azure, require you to change "security groups" (virtual firewalls) using their portal or other APIs (such as their CLI).
Member: Configure BigchainDB Server
To configure BigchainDB Server, run:
bigchaindb configure
The first question is API Server bind? (default `localhost:9984`). To expose the API to the public, bind the API Server to 0.0.0.0:9984. Unless you have specific needs, you can keep the default value for all other questions.
Member: Generate the Private Key and Node id
A Node is identified by the triplet <hostname, node_id, public_key>.
As a Member, it's your duty to create and store securely your private key, and share your hostname, node_id, and public_key with the other members of the network.
To generate all of that, run:
tendermint init
The public_key is stored in the file .tendermint/config/priv_validator.json, and it should look like:
{
"address": "5943A9EF6285791A504918E1D117BC7F6A615C98",
"pub_key": {
"type": "AC26791624DE60",
"value": "W3tqeMCU3d4SHDKqrwQWTahTW/wpieIAKZQxUxLv6rI="
},
"last_height": 0,
"last_round": 0,
"last_step": 0,
"priv_key": {
"type": "954568A3288910",
"value": "3sv9aExgME6MMjx0JoKVy7KtED8PBiPcyAgsYmVizslbe2p4wJTd3hIcMqqvBBZNqFNb/CmJ4gAplDFTEu/qsg=="
}
}
To extract your node_id, run the command:
tendermint show_node_id
An example node_id is 9b989cd5ac65fec52652a457aed6f5fd200edc22.
An example hostname is charlie5.cloudservers.company.com. You can also use a public IP addres, like 46.145.17.32, instead of a hostname, but make sure that IP address won't change.
Share the node_id, pub_key.value and hostname of your Node with all other Members.
Important note on security: each Member should take extra steps to verify the public keys they receive from the other Members have not been tampered with, e.g. a key signing party would be one way.
Coordinator: Initialize the Network
At this point the Coordinator should have received the data from all the Members, and should combine them in the .tendermint/config/genesis.json file:
{
"genesis_time": "0001-01-01T00:00:00Z",
"chain_id": "test-chain-la6HSr",
"validators": [
{
"pub_key": {
"type": "AC26791624DE60",
"value": "<Member 1 public key>"
},
"power": 10,
"name": "<Member 1 name>"
},
{
"pub_key": {
"type": "AC26791624DE60",
"value": "<Member 2 public key>"
},
"power": 10,
"name": "<Member 2 name>"
},
{
"...": { },
},
{
"pub_key": {
"type": "AC26791624DE60",
"value": "<Member N public key>"
},
"power": 10,
"name": "<Member N name>"
}
],
"app_hash": ""
}
The new genesis.json file contains the data that describes the Network. The key name is the Member's moniker; it can be any valid string, but put something human-readable like "Alice's Node Shop".
At this point, the Coordinator must share the new genesis.json file with all Members.
Member: Connect to the Other Members
At this point the Member should have received the genesis.json file.
Important note on security: each Member should verify that the genesis.json file contains the correct public keys.
The Member must copy the genesis.json file in the local .tendermint/config directory. Every Member now shares the same chain_id, genesis_time, used to identify the Network, and the same list of validators.
The Member must edit the .tendermint/config/config.toml file and make the following changes:
...
create_empty_blocks = false
...
persistent_peers = "<Member 1 node id>@<Member 1 hostname>:26656,\
<Member 2 node id>@<Member 2 hostname>:26656,\
<Member N node id>@<Member N hostname>:26656,"
Member: Start MongoDB, BigchainDB and Tendermint
If you installed MongoDB using sudo apt install mongodb, then MongoDB should already be running in the background. You can check using systemctl status mongodb.
If MongoDB isn't running, then you can start it using the command mongod, but that will run it in the foreground. If you want to run it in the background (so it will continue running after you logout), you can use mongod --fork --logpath /var/log/mongodb.log. (You might have to create the /var/log directory if it doesn't already exist.)
If you installed MongoDB using sudo apt install mongodb, then a MongoDB startup script should already be installed (so MongoDB will start automatically when the machine is restarted). Otherwise, you should install a startup script for MongoDB.
To start BigchainDB, one uses the command bigchaindb start but that will run it in the foreground. If you want to run it in the background (so it will continue running after you logout), you can use nohup, tmux, or screen. For example, nohup bigchaindb start 2>&1 > bigchaindb.log &
The recommended approach is to create a startup script for BigchainDB, so it will start right after the boot of the operating system. (As mentioned earlier, MongoDB should already have a startup script.)
To start Tendermint, one uses the command tendermint node but that will run it in the foreground. If you want to run it in the background (so it will continue running after you logout), you can use nohup, tmux, or screen. For example, nohup tendermint node 2>&1 > tendermint.log &
The recommended approach is to create a startup script for Tendermint, so it will start right after the boot of the operating system.
Note: We'll share some example startup scripts in the future. This document is a work in progress.
If you followed the recommended approach and created startup scripts for BigchainDB and Tendermint, then you can reboot the machine now. MongoDB, BigchainDB and Tendermint should all start.
How Others Can Access Your Node
If you followed the above instructions, then your node should be publicly-accessible with BigchainDB Root URL http://hostname:9984 (where hostname is something like bdb7.canada.vmsareus.net or 17.122.200.76). That is, anyone can interact with your node using the BigchainDB HTTP API exposed at that address. The most common way to do that is to use one of the BigchainDB Drivers.
Refreshing Your Node
If you want to refresh your node back to a fresh empty state, then your best bet is to terminate it and deploy a new virtual machine, but if that's not an option, then you can:
- drop the
bigchaindatabase in MongoDB usingbigchaindb drop(but that only works if MongoDB is running) - reset Tendermint using
tendermint unsafe_reset_all - delete the directory
$HOME/.tendermint
Member: Dynamically Add a New Member to the Network
TBD.