[Tarantool-patches] [PATCH 03/12] raft: stop using replication_disconnect_timeout()

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

Raft is being moved to a separate library in src/lib. It means,
it can't depend on anything from box/, including global
replication parameters such as replication_timeout, and functions
like replication_disconnect_timeout().

The patch makes raft stop using replication_disconnect_timeout().
Instead, it stores death timeout in struct raft. It is configured
by box simultaneously with replication_timeout.

Part of #5303
---
 src/box/box.cc    |  2 +-
 src/box/raftlib.c | 13 ++++++-------
 src/box/raftlib.h | 10 +++++++---
 3 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/box/box.cc b/src/box/box.cc
index 8dd92a5f5..25673ed42 100644
--- a/src/box/box.cc
+++ b/src/box/box.cc
@@ -890,7 +890,7 @@ void
 box_set_replication_timeout(void)
 {
 	replication_timeout = box_check_replication_timeout();
-	raft_cfg_death_timeout(box_raft());
+	raft_cfg_death_timeout(box_raft(), replication_disconnect_timeout());
 }
 
 void
diff --git a/src/box/raftlib.c b/src/box/raftlib.c
index 3867c63e0..c156d6f46 100644
--- a/src/box/raftlib.c
+++ b/src/box/raftlib.c
@@ -804,8 +804,7 @@ raft_sm_wait_leader_dead(struct raft *raft)
 	assert(raft->is_candidate);
 	assert(raft->state == RAFT_STATE_FOLLOWER);
 	assert(raft->leader != 0);
-	double death_timeout = replication_disconnect_timeout();
-	ev_timer_set(&raft->timer, death_timeout, death_timeout);
+	ev_timer_set(&raft->timer, raft->death_timeout, raft->death_timeout);
 	ev_timer_start(loop(), &raft->timer);
 }
 
@@ -817,8 +816,7 @@ raft_sm_wait_leader_found(struct raft *raft)
 	assert(raft->is_candidate);
 	assert(raft->state == RAFT_STATE_FOLLOWER);
 	assert(raft->leader == 0);
-	double death_timeout = replication_disconnect_timeout();
-	ev_timer_set(&raft->timer, death_timeout, death_timeout);
+	ev_timer_set(&raft->timer, raft->death_timeout, raft->death_timeout);
 	ev_timer_start(loop(), &raft->timer);
 }
 
@@ -1012,14 +1010,14 @@ raft_cfg_election_quorum(struct raft *raft)
 }
 
 void
-raft_cfg_death_timeout(struct raft *raft)
+raft_cfg_death_timeout(struct raft *raft, double death_timeout)
 {
+	raft->death_timeout = death_timeout;
 	if (raft->state == RAFT_STATE_FOLLOWER && raft->is_candidate &&
 	    raft->leader != 0) {
 		assert(ev_is_active(&raft->timer));
-		double death_timeout = replication_disconnect_timeout();
 		double timeout = ev_timer_remaining(loop(), &raft->timer) -
-				 raft->timer.at + death_timeout;
+				 raft->timer.at + raft->death_timeout;
 		ev_timer_stop(loop(), &raft->timer);
 		ev_timer_set(&raft->timer, timeout, timeout);
 		ev_timer_start(loop(), &raft->timer);
@@ -1080,6 +1078,7 @@ raft_create(struct raft *raft)
 		.volatile_term = 1,
 		.term =	1,
 		.election_timeout = 5,
+		.death_timeout = 5,
 	};
 	ev_timer_init(&raft->timer, raft_sm_schedule_new_election_cb, 0, 0);
 	raft->timer.data = raft;
diff --git a/src/box/raftlib.h b/src/box/raftlib.h
index 805f69d64..b33a20326 100644
--- a/src/box/raftlib.h
+++ b/src/box/raftlib.h
@@ -156,6 +156,11 @@ struct raft {
 	struct fiber *worker;
 	/** Configured election timeout in seconds. */
 	double election_timeout;
+	/**
+	 * Leader death timeout, after which it is considered dead and new
+	 * elections can be started.
+	 */
+	double death_timeout;
 	/**
 	 * Trigger invoked each time any of the Raft node visible attributes are
 	 * changed.
@@ -229,11 +234,10 @@ raft_cfg_election_quorum(struct raft *raft);
 
 /**
  * Configure Raft leader death timeout. I.e. number of seconds without
- * heartbeats from the leader to consider it dead. There is no a separate
- * option. Raft uses replication timeout for that.
+ * heartbeats from the leader to consider it dead.
  */
 void
-raft_cfg_death_timeout(struct raft *raft);
+raft_cfg_death_timeout(struct raft *raft, double death_timeout);
 
 /**
  * Bump the term. When it is persisted, the node checks if there is a leader,
-- 
2.24.3 (Apple Git-128)