aos/network/message_bridge_server.fbs

include "aos/configuration.fbs";

namespace aos.message_bridge;

// Per-channel statistics for any channels being forwarded to other nodes by the
// message bridge server.
table ServerChannelStatistics {
  // Index into the configuration channels list for this channel.
  channel_index:uint64 (id: 0);
  // Total number of messages that were sent (this does not necessarily
  // mean that the message made it to the client).
  sent_packets:uint (id: 1);
  // Total number of messages that were dropped while sending (e.g.,
  // those dropped by the kernel).
  dropped_packets:uint (id: 2);
  // Count of the total number of retries attempted on this channel.
  retry_count:uint (id: 3);
}

// State of the connection.
enum State: ubyte {
  CONNECTED,
  DISCONNECTED,
}

// Statistics from a single connection to a client from this server.
table ServerConnection {
  // The node that we are connected to.
  node:Node (id: 0);

  // Health of this connection.  Connected or not?
  state:State (id: 1);

  // Number of packets that have been dropped (if known).
  dropped_packets:uint (id: 2);

  // Number of packets sent on all channels.
  sent_packets:uint (id: 3);

  // This is the measured monotonic offset for the connected node in
  // nanoseconds.  Add this to our monotonic time to get their
  // monotonic time.
  monotonic_offset:int64 (id: 4);

  // Boot UUID of the client.
  boot_uuid:string (id: 5);

  // Number of extra calls needed to receive a single message
  // (indicates congestion)
  partial_deliveries:uint (id: 6);

  // Time at which we connected to the client as nanoseconds on the local
  // monotonic clock.  This is not populated when not connected, and defaults
  // to monotonic_clock::min_time.
  connected_since_time:int64 = -9223372036854775808 (id: 7);

  // Number of times we've established a connection to the server.
  connection_count:uint (id: 8);

  // Number of times we've had an invalid connection with something wrong in
  // the connection message, but we were able to match which node it was.
  invalid_connection_count:uint (id: 9);

  // Statistics for every channel being forwarded to this node. Ordering is arbitrary;
  // the channels are identified by an index in the ServerChannelStatistics.
  channels:[ServerChannelStatistics] (id: 10);

  // Total number of retries attempted on all channels. Typically due to kernel
  // send buffers filling up.
  retry_count:uint (id: 11);
}

// Statistics for all connections to all the clients.
table ServerStatistics {
  connections:[ServerConnection] (id: 0);

  // Count of timestamp send failures
  timestamp_send_failures:uint64 (id: 1);

  // Number of times we've had an invalid connection with something wrong in
  // the connection message.  The most likely cause is that the config sha256
  // doesn't match between nodes.
  invalid_connection_count:uint (id: 2);
}

root_type ServerStatistics;