fixed append entries

raft/raft.go

@@ -274,20 +274,39 @@ func (rf *Raft) AppendEntries(args *AppendEntriesArgs, reply *AppendEntriesReply
         return
     }
 
+    // // check if existing entry conflicts with new entries
+    // // delete any conflicting entries
+    // for j, entry := range args.Entries {
+    //     if args.PrevLogIndex + j + 1 < len(rf.log) {
+    //         if rf.log[args.PrevLogIndex + j + 1].Term != entry.Term {
+    //             rf.log = rf.log[:args.PrevLogIndex + j + 1]
+    //             break
+    //         }
+    //     }
+    // }
+
+    // // append any new entries
+    // if len(args.Entries) > 0 {
+    //     rf.log = append(rf.log, args.Entries...)
+    // }
+
     // check if existing entry conflicts with new entries
-    // delete any conflicting entries
-    for j, entry := range args.Entries {
-        if args.PrevLogIndex + j + 1 < len(rf.log) {
-            if rf.log[args.PrevLogIndex + j + 1].Term != entry.Term {
-                rf.log = rf.log[:args.PrevLogIndex + j + 1]
+    // delete any conflicting entries, then append new entries
+    conflictIndex := args.PrevLogIndex + 1
+    for i, newEntry := range args.Entries {
+        if conflictIndex < len(rf.log) {
+            // conflict index found within existing log
+            if rf.log[conflictIndex].Term != newEntry.Term {
+                rf.log = rf.log[:conflictIndex]
+                rf.log = append(rf.log, args.Entries[i:]...)
                 break
             }
+        } else {
+            // no conflict found, append new entries after existing log
+            rf.log = append(rf.log, args.Entries[i:]...)
+            break
         }
-    }
-
-    // append any new entries
-    if len(args.Entries) > 0 {
-        rf.log = append(rf.log, args.Entries...)
+        conflictIndex++
     }
 
     // update commit index
@@ -352,12 +371,15 @@ func (rf *Raft) sendHeartbeats() {
             }
             // check if new entries need to be sent
             if len(rf.log) >= rf.nextIndex[server] {
+                entriesCopy := make([]LogEntry, len(rf.log[rf.nextIndex[server]:]))
+                copy(entriesCopy, rf.log[rf.nextIndex[server]:])
+
                 argsServer[server] = AppendEntriesArgs{
                     Term: rf.currentTerm,
                     LeaderId: rf.me,
                     PrevLogIndex: rf.nextIndex[server] - 1,
-                    PrevLogTerm: rf.log[rf.nextIndex[server]-1].Term,
-                    Entries: rf.log[rf.nextIndex[server]:],
+                    PrevLogTerm: rf.log[rf.nextIndex[server] - 1].Term,
+                    Entries: entriesCopy,
                     LeaderCommit: rf.commitIndex,
                 }
             } else {
@@ -365,7 +387,7 @@ func (rf *Raft) sendHeartbeats() {
                     Term: rf.currentTerm,
                     LeaderId: rf.me,
                     PrevLogIndex: rf.nextIndex[server] - 1,
-                    PrevLogTerm: rf.log[rf.nextIndex[server]-1].Term,
+                    PrevLogTerm: rf.log[rf.nextIndex[server] - 1].Term,
                     Entries: []LogEntry{},
                     LeaderCommit: rf.commitIndex,
                 }