raft: fix goldenscript append conflict handling

src/raft/node.rs

@@ -1793,8 +1793,9 @@ mod tests {
  let mut node = self.nodes.remove(&id).ok_or(format!("unknown node {id}"))?;
 
  let old_noderole = Self::format_node_role(&node);
- let old_commit_index = Self::borrow_log(&node).get_commit_index().0;
- let old_last_index = Self::borrow_log(&node).get_last_index().0;
+ let log = Self::borrow_log_mut(&mut node);
+ let old_commit_index = log.get_commit_index().0;
+ let entries = log.scan(..)?.collect::<crate::error::Result<Vec<_>>>()?;
 
  // Apply the transition.
  node = f(node)?;
@@ -1804,10 +1805,11 @@ mod tests {
 
  let log = Self::borrow_log_mut(&mut node);
  let (commit_index, commit_term) = log.get_commit_index();
- // TODO: this doesn't handle replaced indexes. It needs to fetch the
- // index/term of all entries and compare them.
- let appended: Vec<_> =
- log.scan(old_last_index + 1..)?.collect::<crate::error::Result<_>>()?;
+ let mut appended = log.scan(..)?.collect::<crate::error::Result<Vec<_>>>()?;
+ match appended.iter().zip(entries.iter()).position(|(a, e)| a.term != e.term) {
+ Some(i) => appended = appended[i..].to_vec(),
+ None => appended = appended[entries.len()..].to_vec(),
+ }
 
  self.nodes.insert(id, node);
 

src/raft/testscripts/node/append_probe_divergent_first

@@ -193,8 +193,20 @@ deliver 1 2
 n5@4 → n1 Append base=1@1 [2@2 3@2 4@3 5@3 6@4 7@4 8@4]
 n5@4 → n2 Append base=1@1 [2@2 3@2 4@3 5@3 6@4 7@4 8@4]
 n5@4 leader last=8@4 commit=7@4 apply=7 progress={1:1→9 2:1→9 3:7→9 4:7→9}
+n1@4 append 2@2 None
+n1@4 append 3@2 put a=1
+n1@4 append 4@3 None
+n1@4 append 5@3 put b=2
+n1@4 append 6@4 None
+n1@4 append 7@4 put c=3
 n1@4 append 8@4 put d=4
 n1@4 → n5 AppendResponse match_index=8
+n2@4 append 2@2 None
+n2@4 append 3@2 put a=1
+n2@4 append 4@3 None
+n2@4 append 5@3 put b=2
+n2@4 append 6@4 None
+n2@4 append 7@4 put c=3
 n2@4 append 8@4 put d=4
 n2@4 → n5 AppendResponse match_index=8
 

src/raft/testscripts/node/append_probe_divergent_long

@@ -222,7 +222,21 @@ deliver 1 2
 n5@4 → n1 Append base=3@1 [4@2 5@2 6@3 7@3 8@4 9@4 10@4]
 n5@4 → n2 Append base=3@1 [4@2 5@2 6@3 7@3 8@4 9@4 10@4]
 n5@4 leader last=10@4 commit=9@4 apply=9 progress={1:3→11 2:3→11 3:9→11 4:9→11}
+n1@4 append 4@2 None
+n1@4 append 5@2 put c=3
+n1@4 append 6@3 None
+n1@4 append 7@3 put d=4
+n1@4 append 8@4 None
+n1@4 append 9@4 put e=5
+n1@4 append 10@4 put f=6
 n1@4 → n5 AppendResponse match_index=10
+n2@4 append 4@2 None
+n2@4 append 5@2 put c=3
+n2@4 append 6@3 None
+n2@4 append 7@3 put d=4
+n2@4 append 8@4 None
+n2@4 append 9@4 put e=5
+n2@4 append 10@4 put f=6
 n2@4 → n5 AppendResponse match_index=10
 
 deliver 5

src/raft/testscripts/node/append_probe_divergent_short

@@ -149,13 +149,15 @@ deliver 1 2
 ---
 n5@4 → n1 Append base=3@1 [4@2 5@2 6@3 7@3 8@4 9@4 10@4]
 n5@4 → n2 Append base=3@1 [4@2 5@2 6@3 7@3 8@4 9@4 10@4]
+n1@4 append 4@2 None
 n1@4 append 5@2 put c=3
 n1@4 append 6@3 None
 n1@4 append 7@3 put d=4
 n1@4 append 8@4 None
 n1@4 append 9@4 put e=5
 n1@4 append 10@4 put f=6
 n1@4 → n5 AppendResponse match_index=10
+n2@4 append 4@2 None
 n2@4 append 5@2 put c=3
 n2@4 append 6@3 None
 n2@4 append 7@3 put d=4

src/raft/testscripts/node/append_probe_divergent_single

@@ -93,8 +93,10 @@ deliver 1 2
 ---
 n5@2 → n1 Append base=1@1 [2@2 3@2]
 n5@2 → n2 Append base=1@1 [2@2 3@2]
+n1@2 append 2@2 None
 n1@2 append 3@2 put b=2
 n1@2 → n5 AppendResponse match_index=3
+n2@2 append 2@2 None
 n2@2 append 3@2 put b=2
 n2@2 → n5 AppendResponse match_index=3
 

src/raft/testscripts/node/election_candidate_behind_leader

@@ -78,9 +78,11 @@ n5@2 → n2 Heartbeat last_index=2 commit_index=1 read_seq=0
 n5@2 → n3 Heartbeat last_index=2 commit_index=1 read_seq=0
 n5@2 → n4 Heartbeat last_index=2 commit_index=1 read_seq=0
 n1@2 follower() ⇨ n1@2 follower(n5)
+n1@2 append 2@2 None
 n1@2 → n5 AppendResponse match_index=2
 n1@2 → n5 HeartbeatResponse match_index=2 read_seq=0
 n2@2 follower() ⇨ n2@2 follower(n5)
+n2@2 append 2@2 None
 n2@2 → n5 AppendResponse match_index=2
 n2@2 → n5 HeartbeatResponse match_index=2 read_seq=0
 n3@2 follower() ⇨ n3@2 follower(n5)

src/raft/testscripts/node/heartbeat_probe_divergent

@@ -176,6 +176,13 @@ n3@3 → n1 Append base=3@1 [4@2 5@2 6@2 7@3 8@3 9@3 10@3]
 
 deliver 1
 ---
+n1@3 append 4@2 None
+n1@3 append 5@2 put c=3
+n1@3 append 6@2 put d=4
+n1@3 append 7@3 None
+n1@3 append 8@3 put e=5
+n1@3 append 9@3 put f=6
+n1@3 append 10@3 put g=7
 n1@3 → n3 AppendResponse match_index=10
 
 deliver 3