Fallback to use the redis command migration type if the target don't support the ApplyBatch command

src/cluster/slot_migrate.cc

@@ -290,24 +290,36 @@ Status SlotMigrator::startMigration() {
     return s.Prefixed(errFailedToSetImportStatus);
   }
 
+  migration_type_ = srv_->GetConfig()->migrate_type;
+
+  // If the APPLYBATCH command is not supported on the destination,
+  // we will fall back to the redis-command migration type.
+  if (migration_type_ == MigrationType::kRawKeyValue) {
+    bool supported = GET_OR_RET(supportedApplyBatchCommandOnDstNode(*dst_fd_));
+    if (!supported) {
+      LOG(INFO) << "APPLYBATCH command is not supported, use redis command for migration" << s.Msg();
+      migration_type_ = MigrationType::kRedisCommand;
+    }
+  }
+
   LOG(INFO) << "[migrate] Start migrating slot " << migrating_slot_ << ", connect destination fd " << *dst_fd_;
 
   return Status::OK();
 }
 
 Status SlotMigrator::sendSnapshot() {
-  if (srv_->GetConfig()->migrate_type == MigrationType::kRedisCommand) {
+  if (migration_type_ == MigrationType::kRedisCommand) {
     return sendSnapshotByCmd();
-  } else if (srv_->GetConfig()->migrate_type == MigrationType::kRawKeyValue) {
+  } else if (migration_type_ == MigrationType::kRawKeyValue) {
     return sendSnapshotByRawKV();
   }
   return {Status::NotOK, errUnsupportedMigrationType};
 }
 
 Status SlotMigrator::syncWAL() {
-  if (srv_->GetConfig()->migrate_type == MigrationType::kRedisCommand) {
+  if (migration_type_ == MigrationType::kRedisCommand) {
     return syncWALByCmd();
-  } else if (srv_->GetConfig()->migrate_type == MigrationType::kRawKeyValue) {
+  } else if (migration_type_ == MigrationType::kRawKeyValue) {
     return syncWALByRawKV();
   }
   return {Status::NotOK, errUnsupportedMigrationType};
@@ -485,6 +497,33 @@ Status SlotMigrator::setImportStatusOnDstNode(int sock_fd, int status) {
   return Status::OK();
 }
 
+StatusOr<bool> SlotMigrator::supportedApplyBatchCommandOnDstNode(int sock_fd) {
+  std::string cmd = redis::ArrayOfBulkStrings({"command", "info", "applybatch——"});
+  auto s = util::SockSend(sock_fd, cmd);
+  if (!s.IsOK()) {
+    return s.Prefixed("failed to send command info to the destination node");
+  }
+
+  UniqueEvbuf evbuf;
+  if (evbuffer_read(evbuf.get(), sock_fd, -1) <= 0) {
+    return Status::FromErrno("read response error");
+  }
+
+  UniqueEvbufReadln line(evbuf.get(), EVBUFFER_EOL_CRLF_STRICT);
+  if (!line) {
+    return Status::FromErrno("read empty response");
+  }
+
+  if (line[0] == '*') {
+    line = UniqueEvbufReadln(evbuf.get(), EVBUFFER_EOL_LF);
+    if (line && line[0] == '*') {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 Status SlotMigrator::checkSingleResponse(int sock_fd) { return checkMultipleResponses(sock_fd, 1); }
 
 // Commands  |  Response            |  Instance

src/cluster/slot_migrate.h

@@ -119,6 +119,7 @@ class SlotMigrator : public redis::Database {
 
   Status authOnDstNode(int sock_fd, const std::string &password);
   Status setImportStatusOnDstNode(int sock_fd, int status);
+  StatusOr<bool> supportedApplyBatchCommandOnDstNode(int sock_fd);
 
   Status sendSnapshotByCmd();
   Status syncWALByCmd();
@@ -187,6 +188,7 @@ class SlotMigrator : public redis::Database {
   int dst_port_ = -1;
   UniqueFD dst_fd_;
 
+  MigrationType migration_type_ = MigrationType::kRedisCommand;
   std::atomic<int16_t> forbidden_slot_ = -1;
   std::atomic<int16_t> migrating_slot_ = -1;
   int16_t migrate_failed_slot_ = -1;