How to Set Up a BigchainDB Network

You can setup or connect to a network once you have a single node running. Until now, everything could be done by a node operator, by themselves. Now the node operators, also called Members, must share some information with each other, so they can form a network.

There is one special Member who helps coordinate everyone: the Coordinator.

Member: Share hostname, pub_key.value and node_id

Each BigchainDB node is identified by its:

• hostname, i.e. the node’s DNS subdomain, such as bnode.example.com, or its IP address, such as 46.145.17.32
• Tendermint pub_key.value
• Tendermint node_id

The Tendermint pub_key.value is stored in the file $HOME/.tendermint/config/priv_validator.json. That file should look like:

{
  "address": "E22D4340E5A92E4A9AD7C62DA62888929B3921E9",
  "pub_key": {
    "type": "tendermint/PubKeyEd25519",
    "value": "P+aweH73Hii8RyCmNWbwPsa9o4inq3I+0fSfprVkZa0="
  },
  "last_height": "0",
  "last_round": "0",
  "last_step": 0,
  "priv_key": {
    "type": "tendermint/PrivKeyEd25519",
    "value": "AHBiZXdZhkVZoPUAiMzClxhl0VvUp7Xl3YT6GvCc93A/5rB4fvceKLxHIKY1ZvA+xr2jiKercj7R9J+mtWRlrQ=="
  }
}

To get your Tendermint node_id, run the command:

tendermint show_node_id

An example node_id is 9b989cd5ac65fec52652a457aed6f5fd200edc22.

Share your hostname, pub_key.value and node_id with all other Members.

Coordinator: Create & Share the genesis.json File

At this point the Coordinator should have received the data from all the Members, and should combine them in the file $HOME/.tendermint/config/genesis.json:

{
   "genesis_time":"0001-01-01T00:00:00Z",
   "chain_id":"test-chain-la6HSr",
   "consensus_params":{
      "block_size_params":{
         "max_bytes":"22020096",
         "max_txs":"10000",
         "max_gas":"-1"
      },
      "tx_size_params":{
         "max_bytes":"10240",
         "max_gas":"-1"
      },
      "block_gossip_params":{
         "block_part_size_bytes":"65536"
      },
      "evidence_params":{
         "max_age":"100000"
      }
   },
   "validators":[
      {
         "pub_key":{
            "type":"tendermint/PubKeyEd25519",
            "value":"<Member 1 public key>"
         },
         "power":10,
         "name":"<Member 1 name>"
      },
      {
         "pub_key":{
            "type":"tendermint/PubKeyEd25519",
            "value":"<Member 2 public key>"
         },
         "power":10,
         "name":"<Member 2 name>"
      },
      {
         "...":{

         },

      },
      {
         "pub_key":{
            "type":"tendermint/PubKeyEd25519",
            "value":"<Member N public key>"
         },
         "power":10,
         "name":"<Member N name>"
      }
   ],
   "app_hash":""
}

Note: The above consensus_params in the genesis.json are default values.

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.

The Member must copy the genesis.json file into their local $HOME/.tendermint/config directory. Every Member now shares the same chain_id and genesis_time (used to identify the Network), and the same list of validators.

Each Member must edit their $HOME/.tendermint/config/config.toml file and make the following changes:

moniker = "Name of our node"
create_empty_blocks = false
log_level = "main:info,state:info,*:error"

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,"

send_rate = 102400000
recv_rate = 102400000

recheck = false

Note: The list of persistent_peers doesn’t have to include all nodes in the network.

Member: Start MongoDB

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.

Member: Start BigchainDB and Tendermint Using Monit

This section describes how to manage the BigchainDB and Tendermint processes using Monit, a small open-source utility for managing and monitoring Unix processes. BigchainDB and Tendermint are managed together, because if BigchainDB is stopped (or crashes) and is restarted, Tendermint won’t try reconnecting to it. (That’s not a bug. It’s just how Tendermint works.)

Install Monit:

sudo apt install monit

If you installed the bigchaindb Python package as above, you should have the bigchaindb-monit-config script in your PATH now. Run the script to build a configuration file for Monit:

bigchaindb-monit-config

Run Monit as a daemon, instructing it to wake up every second to check on processes:

monit -d 1

Monit will run the BigchainDB and Tendermint processes and restart them when they crash. If the root bigchaindb_ process crashes, Monit will also restart the Tendermint process.

You can check the status by running monit status or monit summary.

By default, it will collect program logs into the ~/.bigchaindb-monit/logs folder.

To learn more about Monit, use monit -h (help) or read the Monit documentation.

Check bigchaindb-monit-config -h if you want to arrange a different folder for logs or some of the Monit internal artifacts.

If you want to start and manage the BigchainDB and Tendermint processes yourself, then look inside the file bigchaindb/pkg/scripts/bigchaindb-monit-config to see how it starts BigchainDB and Tendermint.

How Others Can Access Your Node

If you followed the above instructions, then your node should be publicly-accessible with BigchainDB Root URL https://hostname or http://hostname:9984. 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.