void TestRaft_election_start_increments_term(CuTest * tc)
{
void *r = raft_new();
raft_set_current_term(r, 1);
raft_election_start(r);
CuAssertTrue(tc, 2 == raft_get_current_term(r));
}
void TestRaft_follower_recv_appendentries_add_new_entries_not_already_in_log(
CuTest * tc)
{
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
raft_set_current_term(r, 1);
msg_appendentries_t ae;
msg_appendentries_response_t aer;
memset(&ae, 0, sizeof(msg_appendentries_t));
ae.term = 1;
ae.prev_log_idx = 0;
ae.prev_log_term = 1;
/* include entries */
msg_entry_t e[2];
memset(&e, 0, sizeof(msg_entry_t) * 2);
e[0].id = 1;
e[1].id = 2;
ae.entries = e;
ae.n_entries = 2;
raft_recv_appendentries(r, 1, &ae, &aer);
CuAssertTrue(tc, 1 == aer.success);
CuAssertTrue(tc, 2 == raft_get_log_count(r));
}
/* 5.1 */
void
TestRaft_follower_recv_appendentries_reply_false_if_term_less_than_currentterm(
CuTest * tc)
{
msg_appendentries_t ae;
msg_appendentries_response_t aer, *aerr;
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
void *sender = sender_new(NULL);
/* no leader known at this point */
CuAssertTrue(tc, -1 == raft_get_current_leader(r));
/* term is low */
memset(&ae, 0, sizeof(msg_appendentries_t));
ae.term = 1;
/* higher current term */
raft_set_current_term(r, 5);
raft_recv_appendentries(r, 1, &ae, &aer);
aerr = sender_poll_msg_data(sender);
CuAssertTrue(tc, NULL != aerr);
CuAssertTrue(tc, 0 == aerr->success);
/* rejected appendentries doesn't change the current leader. */
CuAssertTrue(tc, -1 == raft_get_current_leader(r));
}
/* TODO: check if test case is needed */
void
TestRaft_follower_recv_appendentries_updates_currentterm_if_term_gt_currentterm(
CuTest * tc)
{
msg_appendentries_t ae;
msg_appendentries_response_t aer;
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
/* older currentterm */
raft_set_current_term(r, 1);
CuAssertTrue(tc, -1 == raft_get_current_leader(r));
/* newer term for appendentry */
memset(&ae, 0, sizeof(msg_appendentries_t));
/* no prev log idx */
ae.prev_log_idx = 0;
ae.term = 2;
/* appendentry has newer term, so we change our currentterm */
raft_recv_appendentries(r, 1, &ae, &aer);
CuAssertTrue(tc, 1 == aer.success);
/* term has been updated */
CuAssertTrue(tc, 2 == raft_get_current_term(r));
/* and leader has been updated */
CuAssertTrue(tc, 1 == raft_get_current_leader(r));
}
/* Candidate 5.2 */
void TestRaft_follower_dont_grant_vote_if_candidate_has_a_less_complete_log(
CuTest * tc)
{
msg_requestvote_t rv;
msg_requestvote_response_t rvr;
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
/* request vote */
/* vote indicates candidate's log is not complete compared to follower */
memset(&rv, 0, sizeof(msg_requestvote_t));
rv.term = 1;
rv.candidate_id = 1;
rv.last_log_idx = 1;
rv.last_log_term = 1;
/* server's term and idx are more up-to-date */
raft_set_current_term(r, 1);
raft_entry_t ety;
ety.term = 1;
ety.id = 100;
ety.data.len = 4;
ety.data.buf = (unsigned char*)"aaa";
raft_append_entry(r, &ety);
ety.id = 101;
raft_append_entry(r, &ety);
/* vote not granted */
raft_recv_requestvote(r, 1, &rv, &rvr);
CuAssertTrue(tc, 0 == rvr.vote_granted);
}
/* If commitidx > lastApplied: increment lastApplied, apply log[lastApplied]
* to state machine (§5.3) */
void TestRaft_server_increment_lastApplied_when_lastApplied_lt_commitidx(
CuTest* tc)
{
raft_entry_t ety;
void *r = raft_new();
/* must be follower */
raft_set_state(r, RAFT_STATE_FOLLOWER);
raft_set_current_term(r, 1);
raft_set_commit_idx(r, 1);
raft_set_last_applied_idx(r, 0);
/* need at least one entry */
ety.term = 1;
ety.id = 1;
ety.data.buf = "aaa";
ety.data.len = 3;
raft_append_entry(r, &ety);
/* let time lapse */
raft_periodic(r, 1);
CuAssertTrue(tc, 0 != raft_get_last_applied_idx(r));
CuAssertTrue(tc, 1 == raft_get_last_applied_idx(r));
}
/* 5.3 */
void
TestRaft_follower_recv_appendentries_delete_entries_if_conflict_with_new_entries(
CuTest * tc)
{
msg_appendentries_t ae;
msg_appendentries_response_t aer;
raft_entry_t *ety_appended;
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
raft_set_current_term(r, 1);
raft_entry_t ety;
/* increase log size */
char *str1 = "111";
ety.data.buf = str1;
ety.data.len = 3;
ety.id = 1;
ety.term = 1;
raft_append_entry(r, &ety);
CuAssertTrue(tc, 1 == raft_get_log_count(r));
/* this log will be overwritten by the appendentries below */
char *str2 = "222";
ety.data.buf = str2;
ety.data.len = 3;
ety.id = 2;
ety.term = 1;
raft_append_entry(r, &ety);
CuAssertTrue(tc, 2 == raft_get_log_count(r));
CuAssertTrue(tc, NULL != (ety_appended = raft_get_entry_from_idx(r, 2)));
CuAssertTrue(tc, !strncmp(ety_appended->data.buf, str2, 3));
/* pass a appendentry that is newer */
msg_entry_t mety;
memset(&ae, 0, sizeof(msg_appendentries_t));
ae.term = 2;
ae.prev_log_idx = 1;
ae.prev_log_term = 1;
/* include one entry */
memset(&mety, 0, sizeof(msg_entry_t));
char *str3 = "333";
mety.data.buf = str3;
mety.data.len = 3;
mety.id = 3;
ae.entries = &mety;
ae.n_entries = 1;
raft_recv_appendentries(r, 1, &ae, &aer);
CuAssertTrue(tc, 1 == aer.success);
CuAssertTrue(tc, 2 == raft_get_log_count(r));
CuAssertTrue(tc, NULL != (ety_appended = raft_get_entry_from_idx(r, 1)));
CuAssertTrue(tc, !strncmp(ety_appended->data.buf, str1, 3));
}
void TestRaft_server_increase_votes_for_me_when_receive_request_vote_response(
CuTest * tc
)
{
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
raft_set_current_term(r, 1);
CuAssertTrue(tc, 0 == raft_get_nvotes_for_me(r));
msg_requestvote_response_t rvr;
memset(&rvr, 0, sizeof(msg_requestvote_response_t));
rvr.term = 1;
rvr.vote_granted = 1;
raft_recv_requestvote_response(r, 1, &rvr);
CuAssertTrue(tc, 1 == raft_get_nvotes_for_me(r));
}
int raft_recv_requestvote_response(raft_server_t* me_,
raft_node_t* node,
msg_requestvote_response_t* r)
{
raft_server_private_t* me = (raft_server_private_t*)me_;
__log(me_, node, "node responded to requestvote status: %s",
r->vote_granted == 1 ? "granted" : "not granted");
if (!raft_is_candidate(me_))
{
return 0;
}
else if (raft_get_current_term(me_) < r->term)
{
raft_set_current_term(me_, r->term);
raft_become_follower(me_);
return 0;
}
else if (raft_get_current_term(me_) != r->term)
{
/* The node who voted for us would have obtained our term.
* Therefore this is an old message we should ignore.
* This happens if the network is pretty choppy. */
return 0;
}
__log(me_, node, "node responded to requestvote: %d status: %s ct:%d rt:%d",
node, r->vote_granted == 1 ? "granted" : "not granted",
me->current_term,
r->term);
if (1 == r->vote_granted)
{
if (node)
raft_node_vote_for_me(node, 1);
int votes = raft_get_nvotes_for_me(me_);
if (raft_votes_is_majority(me->num_nodes, votes))
raft_become_leader(me_);
}
return 0;
}
void TestRaft_server_recv_requestvote_candidate_step_down_if_term_is_higher_than_current_term(
CuTest * tc
)
{
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
raft_become_candidate(r);
raft_set_current_term(r, 1);
/* current term is less than term */
msg_requestvote_t rv;
memset(&rv, 0, sizeof(msg_requestvote_t));
rv.term = 2;
rv.last_log_idx = 1;
msg_requestvote_response_t rvr;
raft_recv_requestvote(r, 1, &rv, &rvr);
CuAssertTrue(tc, 1 == raft_is_follower(r));
}
/* Reply false if term < currentTerm (§5.1) */
void TestRaft_server_recv_requestvote_reply_false_if_term_less_than_current_term(
CuTest * tc
)
{
msg_requestvote_response_t rvr;
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
raft_set_current_term(r, 2);
/* term is less than current term */
msg_requestvote_t rv;
memset(&rv, 0, sizeof(msg_requestvote_t));
rv.term = 1;
raft_recv_requestvote(r, 1, &rv, &rvr);
CuAssertTrue(tc, 0 == rvr.vote_granted);
}
/* If votedFor is null or candidateId, and candidate's log is at
* least as up-to-date as local log, grant vote (§5.2, §5.4) */
void TestRaft_server_dont_grant_vote_if_we_didnt_vote_for_this_candidate(
CuTest * tc
)
{
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
raft_set_current_term(r, 1);
raft_vote(r, 0);
msg_requestvote_t rv;
memset(&rv, 0, sizeof(msg_requestvote_t));
rv.term = 1;
rv.candidate_id = 1;
rv.last_log_idx = 1;
rv.last_log_term = 1;
msg_requestvote_response_t rvr;
raft_recv_requestvote(r, 1, &rv, &rvr);
CuAssertTrue(tc, 0 == rvr.vote_granted);
}
/* Reply true if term >= currentTerm (§5.1) */
void TestRaft_server_recv_requestvote_reply_true_if_term_greater_than_or_equal_to_current_term(
CuTest * tc
)
{
msg_requestvote_t rv;
msg_requestvote_response_t rvr;
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
raft_set_current_term(r, 1);
/* term is less than current term */
memset(&rv, 0, sizeof(msg_requestvote_t));
rv.term = 2;
rv.last_log_idx = 1;
raft_recv_requestvote(r, 1, &rv, &rvr);
CuAssertTrue(tc, 1 == rvr.vote_granted);
}
/* 5.3 */
void
TestRaft_follower_recv_appendentries_reply_false_if_doesnt_have_log_at_prev_log_idx_which_matches_prev_log_term(
CuTest * tc)
{
msg_entry_t ety;
char *str = "aaa";
msg_appendentries_t ae;
msg_appendentries_response_t aer;
void *r = raft_new();
raft_add_node(r, (void*)1, 1);
raft_add_node(r, (void*)2, 0);
/* term is different from appendentries */
raft_set_current_term(r, 2);
raft_set_commit_idx(r, 1);
raft_set_last_applied_idx(r, 1);
// TODO at log manually?
/* log idx that server doesn't have */
memset(&ae, 0, sizeof(msg_appendentries_t));
ae.term = 2;
ae.prev_log_idx = 1;
/* prev_log_term is less than current term (ie. 2) */
ae.prev_log_term = 1;
/* include one entry */
memset(&ety, 0, sizeof(msg_entry_t));
ety.data.buf = str;
ety.data.len = 3;
ety.id = 1;
ae.entries = &ety;
ae.n_entries = 1;
/* trigger reply */
raft_recv_appendentries(r, 1, &ae, &aer);
/* reply is false */
CuAssertTrue(tc, 0 == aer.success);
}
void raft_become_candidate(raft_server_t* me_)
{
raft_server_private_t* me = (raft_server_private_t*)me_;
int i;
__log(me_, NULL, "becoming candidate");
raft_set_current_term(me_, raft_get_current_term(me_) + 1);
for (i = 0; i < me->num_nodes; i++)
raft_node_vote_for_me(me->nodes[i], 0);
raft_vote(me_, me->node);
me->current_leader = NULL;
raft_set_state(me_, RAFT_STATE_CANDIDATE);
/* we need a random factor here to prevent simultaneous candidates */
/* TODO: this should probably be lower */
me->timeout_elapsed = rand() % me->election_timeout;
for (i = 0; i < me->num_nodes; i++)
if (me->node != me->nodes[i] && raft_node_is_voting(me->nodes[i]))
raft_send_requestvote(me_, me->nodes[i]);
}
int raft_recv_requestvote(raft_server_t* me_,
raft_node_t* node,
msg_requestvote_t* vr,
msg_requestvote_response_t *r)
{
raft_server_private_t* me = (raft_server_private_t*)me_;
if (raft_get_current_term(me_) < vr->term)
{
raft_set_current_term(me_, vr->term);
raft_become_follower(me_);
}
if (__should_grant_vote(me, vr))
{
/* It shouldn't be possible for a leader or candidate to grant a vote
* Both states would have voted for themselves */
assert(!(raft_is_leader(me_) || raft_is_candidate(me_)));
raft_vote_for_nodeid(me_, vr->candidate_id);
r->vote_granted = 1;
/* there must be in an election. */
me->current_leader = NULL;
me->timeout_elapsed = 0;
}
else
r->vote_granted = 0;
__log(me_, node, "node requested vote: %d replying: %s",
node, r->vote_granted == 1 ? "granted" : "not granted");
r->term = raft_get_current_term(me_);
return 0;
}
int raft_recv_appendentries(
raft_server_t* me_,
const int node,
msg_appendentries_t* ae)
{
int i;
raft_server_private_t* me = (void*)me_;
msg_appendentries_response_t r;
me->timeout_elapsed = 0;
__log(me_, NULL, "received appendentries from: %d", node);
r.term = me->current_term;
/* we've found a leader who is legitimate */
if (raft_is_leader(me_) && me->current_term <= ae->term)
raft_become_follower(me_);
/* 1. Reply false if term < currentTerm (�1) */
if (ae->term < me->current_term)
{
__log(me_, NULL, "AE term is less than current term");
r.success = 0;
goto done;
}
#if 0
if (-1 != ae->prev_log_idx &&
ae->prev_log_idx < raft_get_current_idx(me_))
{
__log(me_, NULL, "AE prev_idx is less than current idx");
r.success = 0;
goto done;
}
#endif
/* not the first appendentries we've received */
if (0 != ae->prev_log_idx)
{
raft_entry_t* e;
if ((e = raft_get_entry_from_idx(me_, ae->prev_log_idx)))
{
/* 2. Reply false if log doesn抰 contain an entry at prevLogIndex
whose term matches prevLogTerm (�3) */
if (e->term != ae->prev_log_term)
{
__log(me_, NULL, "AE term doesn't match prev_idx");
r.success = 0;
goto done;
}
/* 3. If an existing entry conflicts with a new one (same index
but different terms), delete the existing entry and all that
follow it (�3) */
raft_entry_t* e2;
if ((e2 = raft_get_entry_from_idx(me_, ae->prev_log_idx+1)))
{
log_delete(me->log, ae->prev_log_idx+1);
}
}
else
{
__log(me_, NULL, "AE no log at prev_idx");
r.success = 0;
goto done;
//assert(0);
}
}
/* 5. If leaderCommit > commitIndex, set commitIndex =
min(leaderCommit, last log index) */
if (raft_get_commit_idx(me_) < ae->leader_commit)
{
raft_entry_t* e;
if ((e = log_peektail(me->log)))
{
raft_set_commit_idx(me_, e->id < ae->leader_commit ?
e->id : ae->leader_commit);
while (1 == raft_apply_entry(me_));
}
}
if (raft_is_candidate(me_))
raft_become_follower(me_);
raft_set_current_term(me_, ae->term);
/* append all entries to log */
for (i=0; i<ae->n_entries; i++)
{
msg_entry_t* cmd;
raft_entry_t* c;
cmd = &ae->entries[i];
/* TODO: replace malloc with mempoll/arena */
c = malloc(sizeof(raft_entry_t));
c->term = me->current_term;
c->len = cmd->len;
c->id = cmd->id;
c->data = malloc(cmd->len);
memcpy(c->data, cmd->data, cmd->len);
if (0 == raft_append_entry(me_, c))
{
__log(me_, NULL, "AE failure; couldn't append entry");
r.success = 0;
goto done;
}
}
r.success = 1;
r.current_idx = raft_get_current_idx(me_);
r.first_idx = ae->prev_log_idx + 1;
done:
if (me->cb.send)
me->cb.send(me->cb_ctx, me, node, RAFT_MSG_APPENDENTRIES_RESPONSE,
(void*)&r, sizeof(msg_appendentries_response_t));
return 1;
}
int raft_recv_appendentries(
raft_server_t* me_,
const int node,
msg_appendentries_t* ae,
msg_appendentries_response_t *r
)
{
raft_server_private_t* me = (raft_server_private_t*)me_;
me->timeout_elapsed = 0;
__log(me_, "received appendentries from: %d", node);
r->term = me->current_term;
/* we've found a leader who is legitimate */
if (raft_is_leader(me_) && me->current_term <= ae->term)
raft_become_follower(me_);
/* 1. Reply false if term < currentTerm (§5.1) */
if (ae->term < me->current_term)
{
__log(me_, "AE term is less than current term");
r->success = 0;
return 0;
}
#if 0
if (-1 != ae->prev_log_idx &&
ae->prev_log_idx < raft_get_current_idx(me_))
{
__log(me_, "AE prev_idx is less than current idx");
r->success = 0;
return 0;
}
#endif
/* not the first appendentries we've received */
if (0 != ae->prev_log_idx)
{
raft_entry_t* e = raft_get_entry_from_idx(me_, ae->prev_log_idx);
if (e)
{
/* 2. Reply false if log doesn't contain an entry at prevLogIndex
whose term matches prevLogTerm (§5.3) */
if (e->term != ae->prev_log_term)
{
__log(me_, "AE term doesn't match prev_idx");
r->success = 0;
return 0;
}
/* 3. If an existing entry conflicts with a new one (same index
but different terms), delete the existing entry and all that
follow it (§5.3) */
raft_entry_t* e2;
e2 = raft_get_entry_from_idx(me_, ae->prev_log_idx + 1);
if (e2)
log_delete(me->log, ae->prev_log_idx + 1);
}
else
{
__log(me_, "AE no log at prev_idx");
r->success = 0;
return 0;
}
}
/* 5. If leaderCommit > commitIndex, set commitIndex =
min(leaderCommit, last log index) */
if (raft_get_commit_idx(me_) < ae->leader_commit)
{
raft_entry_t* e = log_peektail(me->log);
if (e)
{
int id = e->id < ae->leader_commit ? e->id : ae->leader_commit;
raft_set_commit_idx(me_, id);
while (0 == raft_apply_entry(me_))
;
}
}
if (raft_is_candidate(me_))
raft_become_follower(me_);
raft_set_current_term(me_, ae->term);
int i;
/* append all entries to log */
for (i = 0; i < ae->n_entries; i++)
{
msg_entry_t* cmd = &ae->entries[i];
/* TODO: replace malloc with mempoll/arena */
raft_entry_t* c = (raft_entry_t*)malloc(sizeof(raft_entry_t));
c->term = me->current_term;
c->len = cmd->len;
c->id = cmd->id;
c->data = (unsigned char*)malloc(cmd->len);
memcpy(c->data, cmd->data, cmd->len);
if (-1 == raft_append_entry(me_, c))
{
__log(me_, "AE failure; couldn't append entry");
r->success = 0;
return -1;
}
}
r->success = 1;
r->current_idx = raft_get_current_idx(me_);
r->first_idx = ae->prev_log_idx + 1;
return 0;
}
void TestRaft_server_set_currentterm_sets_term(CuTest * tc)
{
void *r = raft_new();
raft_set_current_term(r, 5);
CuAssertTrue(tc, 5 == raft_get_current_term(r));
}
int raft_recv_appendentries(
raft_server_t* me_,
raft_node_t* node,
msg_appendentries_t* ae,
msg_appendentries_response_t *r
)
{
raft_server_private_t* me = (raft_server_private_t*)me_;
me->timeout_elapsed = 0;
if (0 < ae->n_entries)
__log(me_, node, "recvd appendentries from: %lx, t:%d ci:%d lc:%d pli:%d plt:%d #%d",
node,
ae->term,
raft_get_current_idx(me_),
ae->leader_commit,
ae->prev_log_idx,
ae->prev_log_term,
ae->n_entries);
r->term = me->current_term;
if (raft_is_candidate(me_) && me->current_term == ae->term)
{
me->voted_for = -1;
raft_become_follower(me_);
}
else if (me->current_term < ae->term)
{
raft_set_current_term(me_, ae->term);
r->term = ae->term;
raft_become_follower(me_);
}
else if (ae->term < me->current_term)
{
/* 1. Reply false if term < currentTerm (§5.1) */
__log(me_, node, "AE term %d is less than current term %d",
ae->term, me->current_term);
goto fail_with_current_idx;
}
/* Not the first appendentries we've received */
/* NOTE: the log starts at 1 */
if (0 < ae->prev_log_idx)
{
raft_entry_t* e = raft_get_entry_from_idx(me_, ae->prev_log_idx);
if (!e)
{
__log(me_, node, "AE no log at prev_idx %d", ae->prev_log_idx);
goto fail_with_current_idx;
}
/* 2. Reply false if log doesn't contain an entry at prevLogIndex
whose term matches prevLogTerm (§5.3) */
if (raft_get_current_idx(me_) < ae->prev_log_idx)
goto fail_with_current_idx;
if (e->term != ae->prev_log_term)
{
__log(me_, node, "AE term doesn't match prev_term (ie. %d vs %d) ci:%d pli:%d",
e->term, ae->prev_log_term, raft_get_current_idx(me_), ae->prev_log_idx);
assert(me->commit_idx < ae->prev_log_idx);
/* Delete all the following log entries because they don't match */
log_delete(me->log, ae->prev_log_idx);
r->current_idx = ae->prev_log_idx - 1;
goto fail;
}
}
/* 3. If an existing entry conflicts with a new one (same index
but different terms), delete the existing entry and all that
follow it (§5.3) */
if (ae->n_entries == 0 && 0 < ae->prev_log_idx && ae->prev_log_idx + 1 < raft_get_current_idx(me_))
{
assert(me->commit_idx < ae->prev_log_idx + 1);
log_delete(me->log, ae->prev_log_idx + 1);
}
r->current_idx = ae->prev_log_idx;
int i;
for (i = 0; i < ae->n_entries; i++)
{
msg_entry_t* ety = &ae->entries[i];
int ety_index = ae->prev_log_idx + 1 + i;
raft_entry_t* existing_ety = raft_get_entry_from_idx(me_, ety_index);
r->current_idx = ety_index;
if (existing_ety && existing_ety->term != ety->term)
{
assert(me->commit_idx < ety_index);
log_delete(me->log, ety_index);
break;
}
else if (!existing_ety)
break;
}
/* Pick up remainder in case of mismatch or missing entry */
for (; i < ae->n_entries; i++)
{
int e = raft_append_entry(me_, &ae->entries[i]);
if (-1 == e)
goto fail_with_current_idx;
r->current_idx = ae->prev_log_idx + 1 + i;
}
/* 4. If leaderCommit > commitIndex, set commitIndex =
min(leaderCommit, index of most recent entry) */
if (raft_get_commit_idx(me_) < ae->leader_commit)
{
int last_log_idx = max(raft_get_current_idx(me_), 1);
raft_set_commit_idx(me_, min(last_log_idx, ae->leader_commit));
}
/* update current leader because we accepted appendentries from it */
me->current_leader = node;
r->success = 1;
r->first_idx = ae->prev_log_idx + 1;
return 0;
fail_with_current_idx:
r->current_idx = raft_get_current_idx(me_);
fail:
r->success = 0;
r->first_idx = 0;
return -1;
}
int raft_recv_appendentries_response(raft_server_t* me_,
raft_node_t* node,
msg_appendentries_response_t* r)
{
raft_server_private_t* me = (raft_server_private_t*)me_;
__log(me_, node,
"received appendentries response %s ci:%d rci:%d 1stidx:%d",
r->success == 1 ? "SUCCESS" : "fail",
raft_get_current_idx(me_),
r->current_idx,
r->first_idx);
/* Stale response -- ignore */
if (r->current_idx != 0 && r->current_idx <= raft_node_get_match_idx(node))
return 0;
if (!raft_is_leader(me_))
return -1;
/* If response contains term T > currentTerm: set currentTerm = T
and convert to follower (§5.3) */
if (me->current_term < r->term)
{
raft_set_current_term(me_, r->term);
raft_become_follower(me_);
return 0;
}
else if (me->current_term != r->term)
return 0;
/* stop processing, this is a node we don't have in our configuration */
if (!node)
return 0;
if (0 == r->success)
{
/* If AppendEntries fails because of log inconsistency:
decrement nextIndex and retry (§5.3) */
assert(0 <= raft_node_get_next_idx(node));
int next_idx = raft_node_get_next_idx(node);
assert(0 <= next_idx);
if (r->current_idx < next_idx - 1)
raft_node_set_next_idx(node, min(r->current_idx + 1, raft_get_current_idx(me_)));
else
raft_node_set_next_idx(node, next_idx - 1);
/* retry */
raft_send_appendentries(me_, node);
return 0;
}
assert(r->current_idx <= raft_get_current_idx(me_));
raft_node_set_next_idx(node, r->current_idx + 1);
raft_node_set_match_idx(node, r->current_idx);
if (!raft_node_is_voting(node) &&
-1 == me->voting_cfg_change_log_idx &&
raft_get_current_idx(me_) <= r->current_idx + 1 &&
me->cb.node_has_sufficient_logs &&
0 == raft_node_has_sufficient_logs(node)
)
{
raft_node_set_has_sufficient_logs(node);
me->cb.node_has_sufficient_logs(me_, me->udata, node);
}
/* Update commit idx */
int votes = 1; /* include me */
int point = r->current_idx;
int i;
for (i = 0; i < me->num_nodes; i++)
{
if (me->node == me->nodes[i] || !raft_node_is_voting(me->nodes[i]))
continue;
int match_idx = raft_node_get_match_idx(me->nodes[i]);
if (0 < match_idx)
{
raft_entry_t* ety = raft_get_entry_from_idx(me_, match_idx);
if (ety->term == me->current_term && point <= match_idx)
votes++;
}
}
if (me->num_nodes / 2 < votes && raft_get_commit_idx(me_) < point)
raft_set_commit_idx(me_, point);
/* Aggressively send remaining entries */
if (raft_get_entry_from_idx(me_, raft_node_get_next_idx(node)))
raft_send_appendentries(me_, node);
/* periodic applies committed entries lazily */
return 0;
}
