fix always loop when no log need to send

src/kvstore/raftex/Host.cpp

@@ -276,11 +276,24 @@ Host::prepareAppendLogRequest() {
  }
 
  if (lastLogIdSent_ + 1 > part_->wal()->lastLogId()) {
+ // send an emtpy log, if the remote host return error and committedLogId, we try again with the
+ // new lastLogIdSent=committedLogId, then if it still has lastLogIdSent_ + 1 >
+ // part_->wal()->lastLogId(),the committedLogId must be equal to lastLogIdSent, so try again and
+ // the remote host would return success this time.
  LOG_IF(INFO, FLAGS_trace_raft)
  << idStr_ << "My lastLogId in wal is " << part_->wal()->lastLogId()
  << ", but you are seeking " << lastLogIdSent_ + 1
  << ", so i have nothing to send, logIdToSend_ = " << logIdToSend_;
- return nebula::cpp2::ErrorCode::E_RAFT_NO_WAL_FOUND;
+ auto req = std::make_shared<cpp2::AppendLogRequest>();
+ req->space_ref() = part_->spaceId();
+ req->part_ref() = part_->partitionId();
+ req->current_term_ref() = logTermToSend_;
+ req->committed_log_id_ref() = committedLogId_;
+ req->leader_addr_ref() = part_->address().host;
+ req->leader_port_ref() = part_->address().port;
+ req->last_log_term_sent_ref() = lastLogTermSent_;
+ req->last_log_id_sent_ref() = lastLogIdSent_;
+ return req;
  }
 
  auto it = part_->wal()->iterator(lastLogIdSent_ + 1, logIdToSend_);
@@ -303,6 +316,17 @@ Host::prepareAppendLogRequest() {
  entry.log_term_ref() = it->logTerm();
  logs.emplace_back(std::move(entry));
  }
+ while (it->valid()) {
+ if (it->logTerm() < part_->termId()) {
+ cpp2::RaftLogEntry entry;
+ entry.cluster_ref() = it->logSource();
+ entry.log_str_ref() = it->logMsg().toString();
+ entry.log_term_ref() = it->logTerm();
+ logs.emplace_back(std::move(entry));
+ } else {
+ break;
+ }
+ }
  // the last log entry's id is (lastLogIdSent_ + cnt), when iterator is invalid and last log
  // entry's id is not logIdToSend_, which means the log has been rollbacked
  if (!it->valid() && (lastLogIdSent_ + static_cast<int64_t>(logs.size()) != logIdToSend_)) {

src/kvstore/raftex/RaftPart.cpp

@@ -1001,6 +1001,12 @@ void RaftPart::processAppendLogResponses(const AppendLogResponses& resps,
  LOG_EVERY_N(WARNING, 100) << idStr_ << "Only " << numSucceeded
  << " hosts succeeded, Need to try again";
  usleep(1000);
+ {
+ std::lock_guard<std::mutex> g(raftLock_);
+ // wal could be rollback between two cycles, if we still use the old lastLogId, we may always
+ // get E_RAFT_NO_WAL_FOUND
+ lastLogId = std::min(wal_->lastLogId(), lastLogId);
+ }
  replicateLogs(eb, std::move(iter), currTerm, lastLogId, committedId, prevLogTerm, prevLogId);
  }
 }