syntax = "proto3";
package cluster;
import "google/protobuf/any.proto";


message GossipRequest {
  string from_member_id = 2;
  GossipState state = 1;
}

//Ack a gossip request
message GossipResponse {
  GossipState state = 1;
}

//string key is member id
//GossipState is the state of that member
message GossipState {
  map<string, GossipMemberState>  members = 1;
}

//string key is the key of the gossip value, e.g. "heartbeat"
//GossipKeyValue is the value of that key
message GossipMemberState {
  map<string, GossipKeyValue> values = 1;
}

//a known key might be heartbeat. if we locally tag each entry with a local timestamp
//this means that we can measure if we have not received a new heartbeat from one member in some time
//even if we don't know the exact time the heartbeat was issued, due to clock differences.
//we still know when _we_ as in this node, got this data.
//and we can measure time from then til now.
//
//if we got a hear-beat from another node, and X seconds pass, we can assume it to be dead
message GossipKeyValue {
  int64 sequence_number = 2; //version is local to the owner member
  google.protobuf.Any value = 4; //value is any format
  int64  local_timestamp_unix_milliseconds = 5;
}

//special datatype that is known by gossip actor
//set key
//remove key
//get keys
message GossipMap {
  map<string, google.protobuf.Any> items = 1;
}