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Network

Introduction#

The network layer in aelf is vital for maintaining connections and communication between nodes. It supports higher-level logic like synchronization and allows node operators to monitor and manage network operations. aelf uses gRPC for connections to keep the design simple and flexible.

Architecture#

The network consists of three layers:

  • aelf.OS
  • aelf.OS.Core.Network
  • aelf.OS.Network.Grpc

    • aelf.OS#

    This layer monitors and handles network-related events:

  • Transaction Accepted Event: When a transaction is verified.
  • Block Mined Event: When a block is packaged.
  • Block Accepted Event: When a block is executed successfully.
  • New Irreversible Block Found Event: When a new irreversible block is found.

    • It also performs regular tasks:

  • Peer Health Check: Ensures connected peers are healthy.
  • Peer Retry Connection: Attempts to reconnect with unhealthy peers.
  • Network Node Discovery: Finds new nodes.

    • aelf.OS.Core.Network#

    This core module includes:

  • NetworkService: Manages sending/receiving requests, broadcasting items to peers, and handling network exceptions.
  • IPeerPool/PeerPool: Manages active peer connections.
  • IPeer: Defines peer interactions and metrics.
  • IaelfNetworkServer: Manages network lifecycle and connections.

    • aelf.OS.Network.Grpc#

    Implements the infrastructure layer using gRPC:

  • GrpcPeer: Implements IPeer.
  • GrpcStreamPeer: Client-side IPeer implementation (node version >=1.4.0).
  • GrpcStreamBackPeer: Server-side IPeer implementation (node version >=1.4.0).
  • GrpcNetworkServer: Implements IaelfNetworkServer.
  • GrpcServerService: Manages network service interfaces and data exchange.

    • Extra functionalities include:

  • Serializing and deserializing requests.
  • Implementing request/response mechanisms.
  • Authentication.

    • Protocol#

    Nodes use a defined network interface protocol for normal operation and data synchronization.

    Connection#

    DoHandshake#

    When a node connects, it exchanges handshake information. This includes chain status, current height, and more.

  • Request:
    • 1
    rpc DoHandshake (HandshakeRequest) returns (HandshakeReply) {}
  • Handshake Message:
    • 1
    message Handshake {
    2
        HandshakeData handshake_data = 1;
    3
        bytes signature = 2;
    4
        bytes session_id = 3;
    5
    }
  • HandshakeData Message:
    • 1
    message HandshakeData {
    2
        int32 chain_id = 1;
    3
        int32 version = 2;
    4
        int32 listening_port = 3;
    5
        bytes pubkey = 4;
    6
        aelf.Hash best_chain_hash = 5;
    7
        int64 best_chain_height = 6;
    8
        aelf.Hash last_irreversible_block_hash = 7;
    9
        int64 last_irreversible_block_height = 8;
    10
        google.protobuf.Timestamp time = 9;
    11
    }

    ConfirmHandshake#

    Confirms the handshake with the target node.

  • Request:
    • 1
    rpc ConfirmHandshake (ConfirmHandshakeRequest) returns (VoidReply) {}

    Broadcasting#

    BlockBroadcastStream#

    Receives block information after packaging.

  • Request:
    • 1
    rpc BlockBroadcastStream (stream BlockWithTransactions) returns (VoidReply) {}

    TransactionBroadcastStream#

    Receives forwarded transaction information.

  • Request:
    • 1
    rpc TransactionBroadcastStream (stream aelf.Transaction) returns (VoidReply) {}

    AnnouncementBroadcastStream#

    Receives block announcements.

  • Request:
    • 1
    rpc AnnouncementBroadcastStream (stream BlockAnnouncement) returns (VoidReply) {}

    LibAnnouncementBroadcastStream#

    Receives last irreversible block (LIB) announcements.

  • Request:
    • 1
    rpc LibAnnouncementBroadcastStream (stream LibAnnouncement) returns (VoidReply) {}

    Block Request#

    RequestBlock#

    Requests a single block.

  • Request:
    • 1
    rpc RequestBlock (BlockRequest) returns (BlockReply) {}

    RequestBlocks#

    Requests multiple blocks.

  • Request:
    • 1
    rpc RequestBlocks (BlocksRequest) returns (BlockList) {}

    Peer Management#

    Ping#

    Verifies network availability.

  • Request:
    • 1
    rpc Ping (PingRequest) returns (PongReply) {}

    CheckHealth#

    Performs health checks on peers.

  • Request:
    • 1
    rpc CheckHealth (HealthCheckRequest) returns (HealthCheckReply) {}

    Edited on: 14 July 2024 05:07:42 GMT+0