etcdserver: return membership.ErrIDNotFound when the memberID not found

Backport #15095 to 3.4. When promoting a learner, we need to wait until the leader's applied ID catches up to the commitId. Afterwards, check whether the learner ID exist or not, and return `membership.ErrIDNotFound` directly in the API if the member ID not found, to avoid the request being unnecessarily delivered to raft. Signed-off-by: Benjamin Wang <[email protected]>
etcd-io · Jan 13, 2023 · 82f315c · 82f315c
1 parent a577940
commit 82f315c
Showing 1 changed file with 14 additions and 6 deletions.
diff --git a/etcdserver/server.go b/etcdserver/server.go
@@ -1805,6 +1805,10 @@ func (s *EtcdServer) isLearnerReady(id uint64) error {
 		return ErrNotLeader
 	}
 
+	if err := s.waitAppliedIndex(); err != nil {
+		return err
+	}
+
 	var learnerMatch uint64
 	isFound := false
 	leaderID := rs.ID
@@ -1817,12 +1821,16 @@ func (s *EtcdServer) isLearnerReady(id uint64) error {
 		}
 	}
 
-	if isFound {
-		leaderMatch := rs.Progress[leaderID].Match
-		// the learner's Match not caught up with leader yet
-		if float64(learnerMatch) < float64(leaderMatch)*readyPercent {
-			return ErrLearnerNotReady
-		}
+	// We should return an error in API directly, to avoid the request
+	// being unnecessarily delivered to raft.
+	if !isFound {
+		return membership.ErrIDNotFound
+	}
+
+	leaderMatch := rs.Progress[leaderID].Match
+	// the learner's Match not caught up with leader yet
+	if float64(learnerMatch) < float64(leaderMatch)*readyPercent {
+		return ErrLearnerNotReady
 	}
 
 	return nil