github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/kv/kvserver/closedts/ctpb/entry.proto

// Copyright 2018 The Cockroach Authors.
//
// Use of this software is governed by the Business Source License
// included in the file licenses/BSL.txt.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this software will be governed
// by the Apache License, Version 2.0, included in the file
// licenses/APL.txt.

syntax = "proto3";
package cockroach.kv.kvserver.ctupdate;
option go_package = "ctpb";

import "gogoproto/gogo.proto";
import "google/api/annotations.proto";

import "util/hlc/timestamp.proto";

// An Entry is a closed timestamp update. It consists of a closed timestamp
// (i.e. a timestamp at or below which the origin node guarantees no more new
// writes are going to be permitted), an associated epoch in which the origin
// node promises it was live (for the closed timestamp), a map of minimum lease
// applied indexes (which have to be caught up to before being allowed to use
// the closed timestamp) as well as an indicator of whether this update supplies
// a full initial state or an increment to be merged into a previous state. In
// practice, the first Entry received for each epoch is full, while the remainder
// are incremental. An incremental update represents the implicit promise that
// the state accumulated since the last full Entry is the true full state.
message Entry {
  option (gogoproto.goproto_stringer) = false;

  int64 epoch = 1 [(gogoproto.casttype) = "Epoch"];
  util.hlc.Timestamp closed_timestamp = 2 [(gogoproto.nullable) = false];
  map<int32, int64> mlai = 3 [(gogoproto.castkey) = "github.com/cockroachdb/cockroach/pkg/roachpb.RangeID",
    (gogoproto.castvalue) = "LAI",
    (gogoproto.customname) = "MLAI"];
  // Full is true if the emitter promises that any future write to any range
  // mentioned in this Entry will be reflected in a subsequent Entry before any
  // stale follower reads are possible. For example, if range 1 is assigned an
  // MLAI of 12 in this Entry and isn't mentioned in the five subsequent
  // entries, the recipient may behave as if the MLAI of 12 were repeated across
  // all of these entries.
  //
  // In practice, a Full message is received when a stream of Entries is first
  // established (or the Epoch changes), and all other updates are incremental
  // (i.e. not Full).
  bool full = 4;
}

// Reactions flow in the direction opposite to Entries and request for ranges to
// be included in the next Entry. Under rare circumstances, ranges may be omitted
// from closed timestamp updates, and so serving follower reads from them would
// fail. The Reaction mechanism serves to explicitly request the missing information
// when that happens.
message Reaction {
  option (gogoproto.goproto_stringer) = false;

  repeated int32 Requested = 1 [(gogoproto.casttype) = "github.com/cockroachdb/cockroach/pkg/roachpb.RangeID"];
}