Polkadot chain load balancer.

Vedran loadbalancer is used in conjunction with Vedran daemon. Suppose the node owner wants to register to loadbalancer, than it is required to install and run Vedran daemon. Daemon executes the registration process and starts providing all relevant information (ping, metrics) to the Vedran loadbalancer. Please check Vedran daemon repo for more details on the daemon itself.

This is dockerized demo of entire setup with loadbalancer, node and daemon

• Install Docker Engine
• Install Docker Compose

Run demo with docker-compose up

After all components have been started and node has sent first valid metrics report (after 30 seconds), you can invoke RPC methods on localhost:4000 using HTTP requests or on localhost:4000/ws using WebSocket request

You can check available rpc methods with:

curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "rpc_methods"}' http://localhost:4000

This demo starts three separate dockerized components:

• Polkadot node (repository)
• Vedran daemon (repository)
• Vedran loadbalancer

Our compose setup runs dev chain and our load balancer uses Allice account to do payout so you don't have to obtain dev DOTs. Polkadot node operator is Bob (he received payout from Allice). Load balancer in this setup runs payout daily, if you don't wan't to wait, you can run following command which will create additional container (in compose network) and trigger payout from Allice account:

docker run --network vedran_default nodefactory/vedran:v0.3.0 payout --private-key 0xe5be9a5092b81bca64be81d212e7f2f9eba183bb7a90954f7b76361f6edb5c0a --payout-reward 100 --load-balancer-url "http://vedran:4000/ws"

Download prebuild binary from releases. Be careful to chose appropriate binary depending on your OS. For more details on how to run vedran loadbalancer see Starting loadbalancer part.

Alternatively, it is possible to get vedran golang package:

1. Install Golang 1.15 or greater
2. Run the command below

go get github.com/NodeFactoryIo/vedran

3. Run vedran from your Go bin directory. For linux systems it will likely be:

~/go/bin/vedran

Note that if you need to do this, you probably want to add your Go bin directory to your $PATH to make things easier!

First download latest prebuilt binaries from releases and unzip it.

Load balancer is started by invoking start command.

For example ./vedran start --auth-secret=supersecret --private-key=lb-wallet-private-key.

For more information you can always run vedran with --help flag. For list of all commands run vedran --help or for list of all options for specific command run vedran start --help.

Load balancer will expose Polkadot RPC API on port 80 by default (can be changed using flag --server-port)

Vedran loadbalancer supports both HTTP and Websockets protocols for Polkadot RPC API.

• HTTP - available on root path /
• WS - available on separate path /ws

For production use certificates (e.g. https://certbot.eff.org/) should be generated and passsed via flags: --key-file, --cert-file and port changed to 443

Start command will start application on 2 ports that need to be exposed to public:

1. RPC entrypoint to nodes and API for nodes to register to load balancer (default: 80)
2. HTTP tunnel server for creating tunnels between the node and load balancer so node operators don't to have expose nodes to public network (default: 5223)

--auth-secret - authentication secret used for generating tokens

--private-key - loadbalancers wallet private key, used for sending founds on payout

If you want to do anything on Polkadot, Kusama, or Westend, then you'll need to get an account and some DOT, KSM, or WND tokens, respectively. When initializing payout, you will provide loadbalancer with created account and from this account rewards will be sent to connected nodes on payout.

For Westend's WND tokens, see the faucet instructions on the Wiki.

When starting vedran loadbalancer it is possible to configure automatic payout by providing these flags:

--private-key - loadbalancers wallet private key (string representation of hex value prefixed with 0x), used for sending rewards on the payout

--payout-interval - automatic payout interval specified as number of days

--payout-reward - defined total reward amount that will be distributed on the payout (amount in Planck). If omitted, the entire balance of lb wallet will be used as a total reward, and in this case --lb-payout-fee-address must be set

--lb-payout-address - address on which load balancer fee will be sent. If omitted, load balancer fee will be left on load balancer wallet after payout. This flag is required if --payout-reward is not set (or set to -1)

If all flags have been provided, then each {payout-interval} days automatic payout will be started.

It is possible to run payout script at any time by invoking vedran payout command through the console.

--private-key - loadbalancers wallet private key (string representation of hex value prefixed with 0x), used for sending rewards on the payout

--payout-reward - defined total reward amount that will be distributed on the payout (amount in Planck). If omitted, the entire balance of lb wallet will be used as a total reward, and in this case --lb-payout-fee-address must be set

--lb-payout-fee-address - address on which load balancer fee will be sent. If omitted, load balancer fee will be left on load balancer wallet after payout. This flag is required if --payout-reward is not set (or set to -1)

Additionally, it is possible to change URL on which payout script will connect with loadbalancer when executing transactions by setting flag (default value will be http://localhost:80)

--load-balancer-url - loadbalancer URL

You can use subkey tool to get private key for your wallet.

After installing subkey tool call subkey inspect "insert your mnemonic here". You can find private key as Secreet seed. See example output of subkey command:

  Secret seed:      0x1a84771145cdcee05e49142aaff2e5d669ce4b29344a09b973b751ae661acabf
  Public key (hex): 0xa4548fa9b3b15dc4d1c59789952f0ccf6138dd63faf802637895c941f0522d35
  Account ID:       0xa4548fa9b3b15dc4d1c59789952f0ccf6138dd63faf802637895c941f0522d35
  SS58 Address:     5FnAq6wrMzri5V6jLfKgBkbR2rSAMkVAHVYWa3eU7TAV5rv9

POST api/v1/nodes

Register node to loadbalancer. Body should contain details about node:

{
  "id": "string",
  "config_hash": "string",
  "payout_address": "string"
}

Returns token used for invoking rest of API and tunnel_server_address on which daemon can open tunnel toward loadbalancer.

{
  "token": "string",
  "tunnel_server_address": "string"
}

POST api/v1/nodes/pings

Ping loadbalancer from node. Auth token should be in header as X-Auth-Header.

PUT api/v1/nodes/metrics

Send metrics for node. Auth token should be in header as X-Auth-Header. Body should contain metrics as:

{
  "peer_count": "int32",
  "best_block_height": "int64",
  "finalized_block_height": "int64",
  "ready_transaction_count": "int32"
}

GET api/v1/stats

Returns statistics for all nodes (mapped on node payout address).

{
  "node_1_payout_address": {
    "total_pings": "float64",
    "total_requests": "float64"
  },
  "node_2_payout_address": {
    "total_pings": "float64",
    "total_requests": "float64"
  },
}

git clone [email protected]:NodeFactoryIo/vedran.git

Golangci-lint is expected to be installed.

make lint

make build

make test

This project is licensed under Apache 2.0:

• Apache License, Version 2.0, (LICENSE-APACHE)