LogDog: Handle archive failures.

common/api/logdog_coordinator/services/v1/service.proto

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 syntax = "proto3";
 
 package logdog;
 
 import "state.proto";
 import "github.com/luci/luci-go/common/proto/logdog/logpb/log.proto";
@@ skipping 74 matching lines @@
 // ArchiveStreamRequest is the set of caller-supplied data for the ArchiveStream
 // service endpoint.
 message ArchiveStreamRequest {
   // The path of the log stream that was archived.
   string path = 1;
   // If true, the archive includes the full set of log stream entries between
   // [0..terminal_index].
   bool complete = 2;
   // The highest log stream index that was archived.
   int64 terminal_index = 3;
+  // If true, there was an archival error, and the referenced streams should be
+  // considered invalid.
+  bool error = 4;
 
   // The archive URL of the log stream's stream data.
   string stream_url = 10;
   // The size of the log stream's stream data.
   int64 stream_size = 11;
 
   // The archive URL of the log stream's index data.
   string index_url = 20;
   // The size of the log stream's index data.
   int64 index_size = 21;
@@ skipping 19 matching lines @@
 
   // TerminateStream is an idempotent operation to update the stream's terminal
   // index.
   rpc TerminateStream(TerminateStreamRequest) returns (google.protobuf.Empty);
 
   // ArchiveStream is an idempotent operation to record a log stream's archival
   // parameters. It is used by the Archivist service upon successful stream
   // archival.
   rpc ArchiveStream(ArchiveStreamRequest) returns (google.protobuf.Empty);
 }