From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtpng3.m.smailru.net (smtpng3.m.smailru.net [94.100.177.149]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id CC082469719 for ; Sat, 19 Sep 2020 18:50:33 +0300 (MSK) From: Vladislav Shpilevoy References: <3c916b9b7e70c4fbfa2b95c4aeb4146e83c82c58.1599693319.git.v.shpilevoy@tarantool.org> Message-ID: <3e56d915-2078-1181-ae6c-1ee1743e0e1c@tarantool.org> Date: Sat, 19 Sep 2020 17:50:31 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Tarantool-patches] [PATCH v2 09/11] raft: introduce state machine List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: tarantool-patches@dev.tarantool.org, sergepetrenko@tarantool.org, gorcunov@gmail.com And my new changes on top of it, in a separate commit. ==================== diff --git a/src/box/applier.cc b/src/box/applier.cc index c352faf5e..10186ab91 100644 --- a/src/box/applier.cc +++ b/src/box/applier.cc @@ -885,6 +885,11 @@ static int applier_handle_raft(struct applier *applier, struct xrow_header *row) { assert(iproto_type_is_raft_request(row->type)); + if (applier->instance_id == 0) { + diag_set(ClientError, ER_PROTOCOL, "Can't apply a Raft request " + "from an instance without an ID"); + return -1; + } struct raft_request req; struct vclock candidate_clock; diff --git a/src/box/raft.c b/src/box/raft.c index 07a49351f..b3ab94bd7 100644 --- a/src/box/raft.c +++ b/src/box/raft.c @@ -347,6 +347,7 @@ raft_process_msg(const struct raft_request *req, uint32_t source) if (req->vote != 0) { switch (raft.state) { case RAFT_STATE_FOLLOWER: + case RAFT_STATE_LEADER: /* * Can't respond on vote requests when Raft is disabled. */ @@ -386,6 +387,12 @@ raft_process_msg(const struct raft_request *req, uint32_t source) "indirect votes are not allowed"); break; } + if (raft.leader != 0) { + say_info("RAFT: vote request is skipped - the " + "leader is already known - %u", + raft.leader); + break; + } /* * Either the term is new, or didn't vote in the current * term yet. Anyway can vote now. @@ -415,16 +422,6 @@ raft_process_msg(const struct raft_request *req, uint32_t source) } raft_sm_become_leader(); break; - case RAFT_STATE_LEADER: - /* - * If the node is still a leader, it ignores all votes. - * Indeed, if the received vote would be from a new - * term, the node would bump its own term and would - * enter the follower state by now. If the vote is from - * the current term, then the leader can freely ignore - * it. - */ - break; default: unreachable(); } @@ -466,6 +463,12 @@ end: void raft_process_heartbeat(uint32_t source) { + /* + * Raft handles heartbeats from all instances, including anon instances + * which don't participate in Raft. + */ + if (source == 0) + return; /* * When not a candidate - don't wait for anything. Therefore do not care * about the leader being dead. @@ -746,6 +749,7 @@ raft_sm_schedule_new_vote(uint32_t new_vote) { say_info("RAFT: vote for %u, follow", new_vote, raft.volatile_term); assert(raft.volatile_vote == 0); + assert(raft.leader == 0); assert(raft.state == RAFT_STATE_FOLLOWER); raft.volatile_vote = new_vote; raft_sm_pause_and_dump(); @@ -929,15 +933,8 @@ raft_cfg_election_quorum(void) return; if (raft.vote_count < raft_election_quorum()) return; - /* - * The node is a candidate. It means its state if fully synced with - * disk. Otherwise it would be a follower. - */ - assert(!raft.is_write_in_progress); - raft.state = RAFT_STATE_LEADER; - raft.leader = instance_id; + raft_sm_become_leader(); raft_broadcast_new_state(); - box_update_ro_summary(); } void