[logdog] Replace Tumble with push queues.

logdog/api/endpoints/coordinator/services/v1/tasks.proto

Index: logdog/api/endpoints/coordinator/services/v1/tasks.proto
diff --git a/logdog/api/endpoints/coordinator/services/v1/tasks.proto b/logdog/api/endpoints/coordinator/services/v1/tasks.proto
index e06a510737ec4324377d7f71d5dcdae0e2d4c61f..9f722e2bba69b47d31480edfe7efabb78924cc1b 100644
--- a/logdog/api/endpoints/coordinator/services/v1/tasks.proto
+++ b/logdog/api/endpoints/coordinator/services/v1/tasks.proto
@@ -9,6 +9,35 @@ package logdog;
 import "google/protobuf/duration.proto";
 import "google/protobuf/timestamp.proto";
 
+// ArchiveDispatchTask is an internal task used by the Coordinator to schedule
+// an archival dispatch.
+message ArchiveDispatchTask {
+  // The hash ID fo the log stream to archive.

[iannucci, 2017/08/03 19:54:20]

nit: s/fo/for

id is a `prefix/+/path`?

[dnj, 2017/08/03 21:05:46]

Nope, it's the hash of the full path. Within Coordinator code, this is well
understood, so shouldn't need elaboration here.

+  string id = 1;
+
+  // The type of archival task.
+  enum Tag {
+    TERMINATED = 0;
+    EXPIRED = 1;
+  }
+  Tag tag = 2;
+
+  // Don't waste time archiving the log stream until it is at least this old.
+  //
+  // This is in place to prevent overly-aggressive archivals from wasting time
+  // trying, then failing, becuase the log stream data is still being collected
+  // into intermediate storage.
+  google.protobuf.Duration settle_delay = 3;

[iannucci, 2017/08/03 19:54:19]

why is this an aspect of the Task and not e.g. a setting in datastore?

[dnj, 2017/08/03 21:05:46]

It starts as a "luci-config" setting, but is propagated along with the archival
parameters.

+
+  // The amount of time after the task was created that log stream completeness
+  // will be used as a success criteria. If the task's age is older than this
+  // value, completeness will not be enforced.
+  //
+  // The task's age can be calculated by subtracting its lease expiration time
+  // (leaseTimestamp) from its enqueued timestamp (enqueueTimestamp).
+  google.protobuf.Duration complete_period = 4;

[iannucci, 2017/08/03 19:54:19]

same

[dnj, 2017/08/03 21:05:46]

(same)

+}
+
 // ArchiveTask is a task queue task description for the archival of a single
 // log stream.
 message ArchiveTask {