Run

노드 운용 과정을 설명합니다.

참고

노드는 node discovery 프로토콜을 사용해 모든 노드의 주소를 알아낼 수 있습니다.
각 Mitum 모델에는 Digest API가 추가되어 있습니다. 따라서 API 서비스가 기본적으로 제공됩니다.
Digest 설정을 위해 Configuration 를 참고하세요.
Digest가 설정되지 않으면 API 서비스를 위한 데이터가 별도로 처리됩니다.

Running the Standalone Node

노드를 운용하기 전에 Configuration 를 참고해 config 파일을 준비해주세요.

node init

우선, genesis block과 genesis account가 생성되어야 합니다. 메인 currency는 genesis block과 함께 발행되며 genesis account의 잔액으로 저장됩니다.

tutorial.yml : config file

$ ./mitum node init --log-level info <config file>
2021-06-10T05:13:09.232802Z INF dryrun? dryrun=false module=command-init
2021-06-10T05:13:09.235942Z INF prepare to run module=command-init
2021-06-10T05:13:09.236013Z INF prepared module=command-init
2021-06-10T05:13:09.780335419Z INF genesis block created block={"hash":"6HjkXEhTNhPzUTG167jsTEany3dHebDQ5cKGNTNEzcgh","height":0} module=command-init
2021-06-10T05:13:10.786661419Z INF stopped module=command-init
...

참고

만약 이미 저장된 블록이 확인되면 environment already exists: block=0 에러가 발생합니다. 이 에러를 초기화하고 무시하려면 --force 옵션과 함께 실행하세요.

$ ./mitum init <config file> --force

node run

노드가 실행되면 블록체인 스토리지 상태와 합의 참여 상태가 SYNC, JOIN, CONSENSUS 모드로 변경되며 블록 생성이 시작됩니다.

$ ./mitum node run --log-level info <config file>
2021-06-10T05:14:08.225487Z INF dryrun? dryrun=false module=command-run
2021-06-10T05:14:08.228797Z INF prepare to run module=command-run
2021-06-10T05:14:08.228869Z INF prepared module=command-run
2021-06-10T05:14:09.706271049Z INF new blocks found to digest last_block=-2 last_manifest=0 module=command-run
2021-06-10T05:14:09.827980049Z INF digested new blocks module=command-run
2021-06-10T05:14:09.828967049Z INF trying to start http2 server for digest API bind=https://localhost:54320 module=command-run publish=https://localhost:54320
2021-06-10T05:14:11.894638049Z INF new block stored block={"hash":"CC57VpSKPozBRABPnznyMk6QY4GHn7CiSH4zSZBs8Rri","height":1,"round":0} elapsed=17.970959 module=basic-consensus-state proposal_hash=DJBgmoAJ4ef7h7iF6E3gTQ83AjWxbGDGQrmDSiQMrfya voteproof_id=BAg2HCNfBenFebuCM4P4HkDfF1off8FCBcSejdK1j7w6
2021-06-10T05:14:11.907600049Z INF block digested block=1 module=digester

Lookup Genesis Account

파일 시스템에 저장된 블록을 통해 genesis account 정보를 확인할 수 있습니다.

다음은 예시입니다.

$ find blockfs -name "*-states-*" -print | xargs -n 1 gzcat | grep '^{' | jq '. | select(.key == "9g4BAB8nZdzWmrsAomwdvNJU2hA2psvkfTQ5XdLn4F4r-mca:account") | [ "height: "+(.height|tostring), "state_key: " + .key, "address: " + .value.value.address, .operations, .value.value.keys.keys, .value.value.keys.threshold]'
[
    "height: 0",
    "state_key: 9g4BAB8nZdzWmrsAomwdvNJU2hA2psvkfTQ5XdLn4F4r-mca:account",
    "address: CoXPgSxcad3fRAbp2JBEeGcYGEQ7dQhdZGWXLbTHpwuGmca",
    [
        "ECSDvWwxcjbEw2F3E6n6pyQXMsZn2uy7msX19XXDCYi8"
    ],
    [
        {
        "_hint": "mitum-currency-key-v0.0.1",
        "weight": 100,
        "key": "rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu"
        }
    ],
    100
]

$ find blockfs -name "*-states-*" -print | xargs -n 1 gzcat | grep '^{' |jq '. | select(.key == "9g4BAB8nZdzWmrsAomwdvNJU2hA2psvkfTQ5XdLn4F4r-mca-MCC:balance") | [ "height: "+(.height|tostring), "state_key: " + .key, "balance:" + .value.value.amount]'
[
    "height: 0",
    "state_key: 9g4BAB8nZdzWmrsAomwdvNJU2hA2psvkfTQ5XdLn4F4r-mca-MCC:balance",
    "balance:99999999999999999999"
]

height 0 의 genesis account 주소, CoXPgSxcad3fRAbp2JBeeGcYGEQ7dQhdZGWXLTHPwuGmca 가 블록에 저장됩니다.

Lookup using Digest API

Digest API를 통해 계정 정보를 확인할 수 있습니다.

digets 설정 Configuration 에 따른 api 주소는 https://localhost:54320 입니다.

account 정보를 통해 genesis account를 확인하세요.

$ curl --insecure http://localhost:54320/account/CoXPgSxcad3fRAbp2JBEeGcYGEQ7dQhdZGWXLbTHpwuGmca | jq '{_embedded}'
{
    "_embedded": {
        "_hint": "mitum-currency-account-value-v0.0.1",
        "hash": "6vCuuiqaYtNGfPbqfDqA234kiDoueWejd7jMs7dwvq5U",
        "address": "CoXPgSxcad3fRAbp2JBEeGcYGEQ7dQhdZGWXLbTHpwuGmca",
        "keys": {
            "_hint": "mitum-currency-keys-v0.0.1",
            "hash": "9g4BAB8nZdzWmrsAomwdvNJU2hA2psvkfTQ5XdLn4F4r",
            "keys": [
                {
                "_hint": "mitum-currency-key-v0.0.1",
                "weight": 100,
                "key": "rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu"
                }
            ],
            "threshold": 100
        },
        "balance": [
            {
                "_hint": "mitum-currency-amount-v0.0.1",
                "amount": "99999999999999999999",
                "currency": "MCC"
            }
        ],
        "height": 0,
        "previous_height": -2
    }
}

Build Multi Nodes Network

Order of Execution

멀티 노드를 실행할 때 genesis block을 생성하는 첫 노드가 설정되어야 합니다. 첫 노드는 node init 을 통해 genesis block을 생성합니다. genesis block를 만들지 않는 그 외의 노드들은 init 을 실행할 필요가 없습니다.
첫 노드는 init 뒤에 run 을 실행해 노드를 시작합니다.
다른 노드들도 run 로 노드를 시작합니다.
다른 노드들은 sync 과정을 통해 첫 노드의 블록을 따라가며 노드들은 consensus 과정을 통해 블록을 생성합니다.

만약 4 개의 노드가 있고 그 중 n0이 첫 노드라면, 실행 순서는 다음과 같습니다. 모든 4 노드가 suffrage 노드일 때 노드들은 node discovery를 위해 최소 하나의 다른 노드의 publish url을 discovery url로 설정해야 합니다.

# n0 node
$ ./mitum node init <n0 config file>
$ ./mitum node run <n0 config file> --discovery <n1 publish url>

# n1 node
$ ./mitum node run <n1 config file> --discovery <n0 publish url>

# n2 node
$ ./mitum node run <n2 config file> --discovery <n0 publish url>

# n3 node
$ ./mitum node run <n3 config file> --discovery <n0 publish url>

참고

같은 네트워크에서 운용된다면 노드들은 구성 파일의 다음 요소에 대해 같은 값을 가져야 합니다.

genesis-operations
network-id

Four Suffrage Nodes

우리가 네 개의 suffrage 노드들을 운영하려는 상황이라고 가정해봅시다.

우선, 각 노드마다 yml config 파일을 준비하세요.

n0, n1, n2, n3 가 모두 suffrage 노드입니다.

노드에 따라, 합의에 참여하는 노드를 설정해야 합니다.

# Only ``suffrage`` and ``nodes`` part of configuration of suffrage nodes

suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas

nodes:
    - address: n0sas
    publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
    tls-insecure: true
    - address: n1sas
    publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
    tls-insecure: true
    - address: n2sas
    publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
    tls-insecure: true
    - address: n3sas
    publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
    tls-insecure: true

다음은 모든 노드의 전체 yml 구성의 예제입니다.

# n0 node

address: n0sas
genesis-operations:
    - account-keys:
        keys:
            - publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54321
    url: https://127.0.0.1:54321
network-id: mitum
policy:
    threshold: 100
privatekey: Kxt22aSeFzJiDQagrvfXPWbEbrTSPsRxbYm9BhNbNJTsrbPbFnPAmpr
publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
storage:
    blockdata:
        path: ./n0_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27017/n0_mc
suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas
nodes:
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      tls-insecure: true
    - address: n2sas
      publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      tls-insecure: true

# n1 node
address: n1sas
genesis-operations:
    - account-keys:
        keys:
            - privatekey: L5GTSKkRs9NPsXwYgACZdodNUJqCAWjz2BccuR4cAgxJumEZWjokmpr
              publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54331
    url: https://127.0.0.1:54331
network-id: mitum
policy:
    threshold: 100
privatekey: L4R2AZVmxWUiF2FrNEFi6rHwCTdDLQ1JuQHji69SbMcmWUdNMUSFmpr
publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
storage:
    blockdata:
        path: ./n1_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27018/n1_mc
suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas
nodes:
    - address: n0sas
      publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
      tls-insecure: true
    - address: n2sas
      publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      tls-insecure: true

# n2 node
address: n2sas
genesis-operations:
    - account-keys:
        keys:
            - publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54332
    url: https://127.0.0.1:54332
network-id: mitum
policy:
    threshold: 100
privatekey: L3Szj4t3w33YLsGFGeaB3v1vwae82yp5KWPcT7v1Y4WyQkAH7eCRmpr
publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
storage:
    blockdata:
        path: ./n2_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27019/n2_mc
suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas
nodes:
    - address: n0sas
      publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
      tls-insecure: true
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      tls-insecure: true

# n3 node
address: n3sas
genesis-operations:
    - account-keys:
        keys:
            - publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54333
    url: https://127.0.0.1:54333
network-id: mitum
policy:
    threshold: 100
privatekey: KwxfBSzwevSggJz2grf8FWrjvXzrctY3WismTy6GNdJpWXe5tF5Lmpr
publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
storage:
    blockdata:
        path: ./n3_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27020/n3_mc
suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas
nodes:
    - address: n0sas
      publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
      tls-insecure: true
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      tls-insecure: true
    - address: n2sas
      publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
      tls-insecure: true

Four Suffrage Nodes and One Sync Node

네 개의 suffrage 노드와 하나의 sync 노드(non-suffrage)를 운영하는 경우,

각 노드에 대해 yml config 파일을 준비하세요.

n0, n1, n2, n3 는 suffrage 노드이며 n4 가 sync 노드입니다.

suffrage 노드들(n0, n1, n2, n3) 구성의 suffrage 와 nodes 는 다음과 같습니다.

suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas

nodes:
    - address: n0sas
      publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
      tls-insecure: true
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      tls-insecure: true
    - address: n2sas
      publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      tls-insecure: true

sync 노드(n4) 구성의 suffrage 와 nodes 은 다음과 같습니다.

# suffrage and nodes part of configuration

suffrage:
    nodes:
        - n1sas
        - n3sas
nodes:
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      url: https://127.0.0.1:54331
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      url: https://127.0.0.1:54351
      tls-insecure: true

다음은 모든 노드의 전체 yml의 예제입니다.

# n0 node(Suffrage node)

address: n0sas
genesis-operations:
    - account-keys:
        keys:
            - publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54321
    url: https://127.0.0.1:54321
network-id: mitum
policy:
    threshold: 100
privatekey: Kxt22aSeFzJiDQagrvfXPWbEbrTSPsRxbYm9BhNbNJTsrbPbFnPAmpr
publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
storage:
    blockdata:
        path: ./n0_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27017/n0_mc
suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas
nodes:
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      tls-insecure: true
    - address: n2sas
      publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      tls-insecure: true

# n1 node(Suffrage node)

address: n1sas
genesis-operations:
    - account-keys:
        keys:
            - publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54331
    url: https://127.0.0.1:54331
network-id: mitum
policy:
    threshold: 100
privatekey: L4R2AZVmxWUiF2FrNEFi6rHwCTdDLQ1JuQHji69SbMcmWUdNMUSFmpr
publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
storage:
    blockdata:
        path: ./n1_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27018/n1_mc
suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas
nodes:
    - address: n0sas
      publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
      tls-insecure: true
    - address: n2sas
      publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      tls-insecure: true

# n2 node(Suffrage node)

address: n2sas
genesis-operations:
    - account-keys:
        keys:
            - publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54332
    url: https://127.0.0.1:54332
network-id: mitum
policy:
    threshold: 100
privatekey: L3Szj4t3w33YLsGFGeaB3v1vwae82yp5KWPcT7v1Y4WyQkAH7eCRmpr
publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
storage:
    blockdata:
        path: ./n2_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27019/n2_mc
suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas
nodes:
    - address: n0sas
      publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
      tls-insecure: true
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      tls-insecure: true

# n3 node(Suffrage node)

address: n3sas
genesis-operations:
    - account-keys:
        keys:
            - publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54333
    url: https://127.0.0.1:54333
network-id: mitum
policy:
    threshold: 100
privatekey: KwxfBSzwevSggJz2grf8FWrjvXzrctY3WismTy6GNdJpWXe5tF5Lmpr
publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
storage:
    blockdata:
        path: ./n3_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27020/n3_mc
suffrage:
    nodes:
        - n0sas
        - n1sas
        - n2sas
        - n3sas
nodes:
    - address: n0sas
      publickey: skRdC6GGufQ5YLwEipjtdaL2Zsgkxo3YCjp1B6w5V4bDmpu
      tls-insecure: true
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      tls-insecure: true
    - address: n2sas
      publickey: wfVsNvKaGbzB18hwix9L3CEyk5VM8GaogdRT4fD3Z6Zdmpu
      tls-insecure: true

# n4 node(Sync node)

address: n4sas
genesis-operations:
    - account-keys:
        keys:
            - publickey: rcrd3KA2wWNhKdAP8rHRzfRmgp91oR9mqopckyXRmCvGmpu
              weight: 100
        threshold: 100
    currencies:
        - balance: "99999999999999999999"
          currency: MCC
    type: genesis-currencies
network:
    bind: https://0.0.0.0:54334
    url: https://127.0.0.1:54334
network-id: mitum
policy:
    threshold: 67
privatekey: KyKM3JtH8M9iBQrcFx4Lubi13Bg8pUPVYvxhihEfkiiqRRWYjjr4mpr
publickey: 2BQkVjJpMdx4BFEhfTtf1oTaG4nLN148Dfax3ZnWybA2bmpu
storage:
    blockdata:
        path: ./n4_data/blockfs
    database:
        uri: mongodb://127.0.0.1:27021/n4_mc
suffrage:
    nodes:
        - n1sas
        - n3sas
nodes:
    - address: n1sas
      publickey: ktJ4Lb6VcmjrbexhDdJBMnXPXfpGWnNijacdxD2SbvRMmpu
      url: https://127.0.0.1:54331
      tls-insecure: true
    - address: n3sas
      publickey: vAydAnFCHoYV6VDUhgToWaiVEtn5V4SXEFpSJVcTtRxbmpu
      url: https://127.0.0.1:54333
      tls-insecure: true

Node Discovery Scenario

다음은 Node Discovery 시나리오의 한 예제입니다.

case 0

All nodes are looking at each other
discoveries of n0: n1, n2
discoveries of n1: n0, n2
discoveries of n2: n0, n1
all joined

case 1

All nodes are looking at the same node and only one node is looking at the other node.
discoveries of n0: n1
discoveries of n1: n0
discoveries of n2: n0
all joined

case 2

All nodes are looking at each other.
discoveries of n0: n1
discoveries of n1: n2
discoveries of n2: n1
all joined

case 3

One node is looking at no one, but another node is looking at it.
discoveries of n0: none
discoveries of n1: n2
discoveries of n2: n0
all joined

case 4

A node sees no one, but no other nodes see it.
discoveries of n0: none
discoveries of n1: n2
discoveries of n2: n1
n1, n2: connected to each other
n0: disconnected