[Tarantool-patches] [PATCH v2 01/11] applier: store instance_id in struct applier

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Applier is going to need its numeric ID in order to tell the
future Raft module who is a sender of a Raft message. An
alternative would be to add sender ID to each Raft message, but
this looks like a crutch. Moreover, applier still needs to know
its numeric ID in order to notify Raft about heartbeats from the
peer node.

Needed for #1146
---
In the previous version applier set its ID on its own. But that didn't work
somewhy. It happened, that on master the ID was never set after bootstrap. Tbh
I didn't find why, and just moved the ID assignment to another more suitable
place. To the same where replica gets its ID and where an applier is associated
with a replica.

 src/box/applier.h      | 2 ++
 src/box/replication.cc | 7 ++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/box/applier.h b/src/box/applier.h
index 6e979a806..15ca1fcfd 100644
--- a/src/box/applier.h
+++ b/src/box/applier.h
@@ -95,6 +95,8 @@ struct applier {
 	ev_tstamp lag;
 	/** The last box_error_code() logged to avoid log flooding */
 	uint32_t last_logged_errcode;
+	/** Remote instance ID. */
+	uint32_t instance_id;
 	/** Remote instance UUID */
 	struct tt_uuid uuid;
 	/** Remote URI (string) */
diff --git a/src/box/replication.cc b/src/box/replication.cc
index ef0e2411d..744236b99 100644
--- a/src/box/replication.cc
+++ b/src/box/replication.cc
@@ -247,7 +247,8 @@ replica_set_id(struct replica *replica, uint32_t replica_id)
 						   tt_uuid_str(&replica->uuid));
 	}
 	replicaset.replica_by_id[replica_id] = replica;
-
+	if (replica->applier != NULL)
+		replica->applier->instance_id = replica_id;
 	say_info("assigned id %d to replica %s",
 		 replica->id, tt_uuid_str(&replica->uuid));
 	replica->anon = false;
@@ -273,6 +274,8 @@ replica_clear_id(struct replica *replica)
 		instance_id = REPLICA_ID_NIL;
 	}
 	replica->id = REPLICA_ID_NIL;
+	if (replica->applier != NULL)
+		replica->applier->instance_id = 0;
 	say_info("removed replica %s", tt_uuid_str(&replica->uuid));
 
 	/*
@@ -301,12 +304,14 @@ replica_set_applier(struct replica *replica, struct applier *applier)
 	replica->applier = applier;
 	trigger_add(&replica->applier->on_state,
 		    &replica->on_applier_state);
+	applier->instance_id = replica->id;
 }
 
 void
 replica_clear_applier(struct replica *replica)
 {
 	assert(replica->applier != NULL);
+	replica->applier->instance_id = 0;
 	replica->applier = NULL;
 	trigger_clear(&replica->on_applier_state);
 }
-- 
2.21.1 (Apple Git-122.3)