@SuppressWarnings("unchecked")
  protected AppendRequest buildAppendEmptyRequest(MemberState member) {
    Entry prevEntry = getPrevEntry(member);

    ServerMember leader = context.getLeader();
    return AppendRequest.builder()
      .withTerm(context.getTerm())
      .withLeader(leader != null ? leader.id() : 0)
      .withLogIndex(prevEntry != null ? prevEntry.getIndex() : 0)
      .withLogTerm(prevEntry != null ? prevEntry.getTerm() : 0)
      .withEntries(Collections.EMPTY_LIST)
      .withCommitIndex(context.getCommitIndex())
      .withGlobalIndex(context.getGlobalIndex())
      .build();
  }
@ SuppressWarnings ( "unchecked" ) protected AppendRequest buildAppendEmptyRequest ( MemberState member ) { Entry prevEntry = getPrevEntry ( member ) ; ServerMember leader = context . getLeader ( ) ; return AppendRequest . builder ( ) . withTerm ( context . getTerm ( ) ) . withLeader ( leader != null ? leader . id ( ) : 0 ) . withLogIndex ( prevEntry != null ? prevEntry . getIndex ( ) : 0 ) . withLogTerm ( prevEntry != null ? prevEntry . getTerm ( ) : 0 ) . withEntries ( Collections . EMPTY_LIST ) . withCommitIndex ( context . getCommitIndex ( ) ) . withGlobalIndex ( context . getGlobalIndex ( ) ) . build ( ) ; }
Builds an empty AppendEntries request.
<p>
Empty append requests are used as heartbeats to followers.