feat: start snapshot in recovery mode of sync repl mgr with lastMatchTerm in reply msg

source/libs/sync/inc/syncMessage.h

@@ -105,7 +105,7 @@ typedef struct SyncAppendEntriesReply {
   SRaftId  destId;
   // private data
   SyncTerm  term;
-  SyncTerm  privateTerm;
+  SyncTerm  lastMatchTerm;
   bool      success;
   SyncIndex matchIndex;
   SyncIndex lastSendIndex;

source/libs/sync/inc/syncPipeline.h

@@ -103,7 +103,7 @@ int32_t         syncLogBufferReInit(SSyncLogBuffer* pBuf, SSyncNode* pNode);
 int64_t syncLogBufferGetEndIndex(SSyncLogBuffer* pBuf);
 int32_t syncLogBufferAppend(SSyncLogBuffer* pBuf, SSyncNode* pNode, SSyncRaftEntry* pEntry);
 int32_t syncLogBufferAccept(SSyncLogBuffer* pBuf, SSyncNode* pNode, SSyncRaftEntry* pEntry, SyncTerm prevTerm);
-int64_t syncLogBufferProceed(SSyncLogBuffer* pBuf, SSyncNode* pNode);
+int64_t syncLogBufferProceed(SSyncLogBuffer* pBuf, SSyncNode* pNode, SyncTerm* pMatchTerm);
 int32_t syncLogBufferCommit(SSyncLogBuffer* pBuf, SSyncNode* pNode, int64_t commitIndex);
 int32_t syncLogBufferReset(SSyncLogBuffer* pBuf, SSyncNode* pNode);
 

source/libs/sync/src/syncAppendEntries.c

@@ -206,7 +206,7 @@ int32_t syncNodeOnAppendEntries(SSyncNode* ths, const SRpcMsg* pRpcMsg) {
   accepted = true;
 
 _SEND_RESPONSE:
-  pReply->matchIndex = syncLogBufferProceed(ths->pLogBuf, ths);
+  pReply->matchIndex = syncLogBufferProceed(ths->pLogBuf, ths, &pReply->lastMatchTerm);
   bool matched = (pReply->matchIndex >= pReply->lastSendIndex);
   if (accepted && matched) {
     pReply->success = true;

source/libs/sync/src/syncMain.c

@@ -2170,7 +2170,7 @@ int32_t syncNodeAppend(SSyncNode* ths, SSyncRaftEntry* pEntry) {
   }
 
   // proceed match index, with replicating on needed
-  SyncIndex matchIndex = syncLogBufferProceed(ths->pLogBuf, ths);
+  SyncIndex matchIndex = syncLogBufferProceed(ths->pLogBuf, ths, NULL);
 
   sDebug("vgId:%d, append raft entry. index: %" PRId64 ", term: %" PRId64 " pBuf: [%" PRId64 " %" PRId64 " %" PRId64
          ", %" PRId64 ")",

source/libs/sync/src/syncPipeline.c

@@ -76,17 +76,17 @@ SyncTerm syncLogReplMgrGetPrevLogTerm(SSyncLogReplMgr* pMgr, SSyncNode* pNode, S
 
   if (prevIndex == -1) return 0;
 
-  if (index - 1 > pBuf->matchIndex) {
+  if (prevIndex > pBuf->matchIndex) {
     terrno = TSDB_CODE_WAL_LOG_NOT_EXIST;
     return -1;
   }
 
   ASSERT(index - 1 == prevIndex);
 
-  if (index - 1 >= pBuf->startIndex) {
-    pEntry = pBuf->entries[(index + pBuf->size) % pBuf->size].pItem;
+  if (prevIndex >= pBuf->startIndex) {
+    pEntry = pBuf->entries[(prevIndex + pBuf->size) % pBuf->size].pItem;
     ASSERT(pEntry != NULL && "no log entry found");
-    prevLogTerm = pBuf->entries[(index + pBuf->size) % pBuf->size].prevLogTerm;
+    prevLogTerm = pEntry->term;
     return prevLogTerm;
   }
 
@@ -354,7 +354,7 @@ int32_t syncLogStorePersist(SSyncLogStore* pLogStore, SSyncRaftEntry* pEntry) {
   return 0;
 }
 
-int64_t syncLogBufferProceed(SSyncLogBuffer* pBuf, SSyncNode* pNode) {
+int64_t syncLogBufferProceed(SSyncLogBuffer* pBuf, SSyncNode* pNode, SyncTerm* pMatchTerm) {
   taosThreadMutexLock(&pBuf->mutex);
   syncLogBufferValidate(pBuf);
 
@@ -419,6 +419,9 @@ int64_t syncLogBufferProceed(SSyncLogBuffer* pBuf, SSyncNode* pNode) {
 
 _out:
   pBuf->matchIndex = matchIndex;
+  if (pMatchTerm) {
+    *pMatchTerm = pBuf->entries[(matchIndex + pBuf->size) % pBuf->size].pItem->term;
+  }
   syncLogBufferValidate(pBuf);
   taosThreadMutexUnlock(&pBuf->mutex);
   return matchIndex;
@@ -615,16 +618,16 @@ int32_t syncLogReplMgrProcessReplyInRecoveryMode(SSyncLogReplMgr* pMgr, SSyncNod
   ASSERT(pMgr->restored == false);
   char     host[64];
   uint16_t port;
-  syncUtilU642Addr(pMsg->srcId.addr, host, sizeof(host), &port);
+  syncUtilU642Addr(destId.addr, host, sizeof(host), &port);
 
   if (pMgr->endIndex == 0) {
     ASSERT(pMgr->startIndex == 0);
     ASSERT(pMgr->matchIndex == 0);
     if (pMsg->matchIndex < 0) {
       pMgr->restored = true;
-      sInfo("vgId:%d, sync log repl mgr of peer %s:%d restored. pMgr(rs:%d): [%" PRId64 " %" PRId64 ", %" PRId64
+      sInfo("vgId:%d, sync log repl mgr of peer %s:%d (%" PRIx64 ") restored. pMgr(rs:%d): [%" PRId64 " %" PRId64 ", %" PRId64
             "), pBuf: [%" PRId64 " %" PRId64 " %" PRId64 ", %" PRId64 ")",
-            pNode->vgId, host, port, pMgr->restored, pMgr->startIndex, pMgr->matchIndex, pMgr->endIndex,
+            pNode->vgId, host, port, destId.addr, pMgr->restored, pMgr->startIndex, pMgr->matchIndex, pMgr->endIndex,
             pBuf->startIndex, pBuf->commitIndex, pBuf->matchIndex, pBuf->endIndex);
       return 0;
     }
@@ -638,9 +641,9 @@ int32_t syncLogReplMgrProcessReplyInRecoveryMode(SSyncLogReplMgr* pMgr, SSyncNod
 
     if (pMsg->matchIndex == pMsg->lastSendIndex) {
       pMgr->restored = true;
-      sInfo("vgId:%d, sync log repl mgr of peer %s:%d restored. pMgr(rs:%d): [%" PRId64 " %" PRId64 ", %" PRId64
+      sInfo("vgId:%d, sync log repl mgr of peer %s:%d (%" PRIx64 ") restored. pMgr(rs:%d): [%" PRId64 " %" PRId64 ", %" PRId64
             "), pBuf: [%" PRId64 " %" PRId64 " %" PRId64 ", %" PRId64 ")",
-            pNode->vgId, host, port, pMgr->restored, pMgr->startIndex, pMgr->matchIndex, pMgr->endIndex,
+            pNode->vgId, host, port, destId.addr, pMgr->restored, pMgr->startIndex, pMgr->matchIndex, pMgr->endIndex,
             pBuf->startIndex, pBuf->commitIndex, pBuf->matchIndex, pBuf->endIndex);
       return 0;
     }
@@ -648,23 +651,38 @@ int32_t syncLogReplMgrProcessReplyInRecoveryMode(SSyncLogReplMgr* pMgr, SSyncNod
     (void)syncLogReplMgrReset(pMgr);
   }
 
-  // check existence of WAl log
+  // check last match term
+  SyncTerm  term = -1;
   SyncIndex firstVer = pNode->pLogStore->syncLogBeginIndex(pNode->pLogStore);
-  if (pMsg->matchIndex + 1 < firstVer) {
+  SyncIndex index = TMIN(pMsg->matchIndex, pNode->pLogBuf->matchIndex);
+
+  if (pMsg->matchIndex < pNode->pLogBuf->matchIndex) {
+    term = syncLogReplMgrGetPrevLogTerm(pMgr, pNode, index + 1);
+
+    if (term < 0 || (term != pMsg->lastMatchTerm && (index + 1 == firstVer || index == firstVer))) {
+      ASSERT(term >= 0 || terrno == TSDB_CODE_WAL_LOG_NOT_EXIST);
       if (syncNodeStartSnapshot(pNode, &destId) < 0) {
-      sError("vgId:%d, failed to start snapshot for dest: 0x%016" PRIx64, pNode->vgId, destId.addr);
+        sError("vgId:%d, failed to start snapshot for peer %s:%d", pNode->vgId, host, port);
       }
       return 0;
     }
 
-  // send match index
-  SyncIndex index = TMIN(pMsg->matchIndex, pNode->pLogBuf->matchIndex);
+    ASSERT(index + 1 >= firstVer);
+
+    if (term == pMsg->lastMatchTerm) {
+      index = index + 1;
+      ASSERT(index <= pNode->pLogBuf->matchIndex);
+    } else {
+      ASSERT(index > firstVer);
+    }
+  }
+
+  // attempt to replicate the raft log at index
   bool barrier = false;
-  SyncTerm  term = -1;
   ASSERT(index >= 0);
   if (syncLogBufferReplicateOneTo(pMgr, pNode, index, &term, &destId, &barrier) < 0) {
-    sError("vgId:%d, failed to replicate log entry since %s. index: %" PRId64 ", dest: 0x%016" PRIx64 "", pNode->vgId,
-           terrstr(), index, destId.addr);
+    sError("vgId:%d, failed to replicate log entry since %s. index: %" PRId64 ", peer %s:%d", pNode->vgId,
+           terrstr(), index, host, port);
     return -1;
   }
 

source/libs/sync/src/syncUtil.c

@@ -373,7 +373,7 @@ void syncLogSendAppendEntriesReply(SSyncNode* pSyncNode, const SyncAppendEntries
   sNTrace(pSyncNode,
           "send sync-append-entries-reply to %s:%d, {term:%" PRId64 ", pterm:%" PRId64
           ", success:%d, lsend-index:%" PRId64 ", match:%" PRId64 "}, %s",
-          host, port, pMsg->term, pMsg->privateTerm, pMsg->success, pMsg->lastSendIndex, pMsg->matchIndex, s);
+          host, port, pMsg->term, pMsg->lastMatchTerm, pMsg->success, pMsg->lastSendIndex, pMsg->matchIndex, s);
 }
 
 void syncLogRecvAppendEntriesReply(SSyncNode* pSyncNode, const SyncAppendEntriesReply* pMsg, const char* s) {
@@ -384,7 +384,7 @@ void syncLogRecvAppendEntriesReply(SSyncNode* pSyncNode, const SyncAppendEntries
   sNTrace(pSyncNode,
           "recv sync-append-entries-reply from %s:%d {term:%" PRId64 ", pterm:%" PRId64
           ", success:%d, lsend-index:%" PRId64 ", match:%" PRId64 "}, %s",
-          host, port, pMsg->term, pMsg->privateTerm, pMsg->success, pMsg->lastSendIndex, pMsg->matchIndex, s);
+          host, port, pMsg->term, pMsg->lastMatchTerm, pMsg->success, pMsg->lastSendIndex, pMsg->matchIndex, s);
 }
 
 void syncLogSendHeartbeat(SSyncNode* pSyncNode, const SyncHeartbeat* pMsg, const char* s) {