From ebe256d61c0456e58fd8ce479d7a5947f908ad25 Mon Sep 17 00:00:00 2001
From: tangcong <tangcong506@gmail.com>
Date: Tue, 3 Mar 2020 17:26:04 +0800
Subject: [PATCH 1/3] auth: print warning log when error is ErrAuthOldRevision

---
 auth/store.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/auth/store.go b/auth/store.go
index 5672a9440e1..80297458494 100644
--- a/auth/store.go
+++ b/auth/store.go
@@ -851,8 +851,13 @@ func (as *authStore) isOpPermitted(userName string, revision uint64, key, rangeE
 	if revision == 0 {
 		return ErrUserEmpty
 	}
-
-	if revision < as.Revision() {
+	rev := as.Revision()
+	if revision < rev {
+		as.lg.Warn("request auth revision is less than current node auth revision",
+			zap.Uint64("current node auth revision", rev),
+			zap.Uint64("request auth revision", revision),
+			zap.ByteString("request key", key),
+			zap.Error(ErrAuthOldRevision))
 		return ErrAuthOldRevision
 	}
 

From 0d084d3a08f9eeff66f06ba69bb8b972a485d4f0 Mon Sep 17 00:00:00 2001
From: tangcong <tangcong506@gmail.com>
Date: Tue, 3 Mar 2020 17:38:37 +0800
Subject: [PATCH 2/3] auth: cleanup saveConsistentIndex in NewAuthStore

---
 auth/store.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/auth/store.go b/auth/store.go
index 80297458494..beb07c0874c 100644
--- a/auth/store.go
+++ b/auth/store.go
@@ -1070,7 +1070,6 @@ func NewAuthStore(lg *zap.Logger, be backend.Backend, tp TokenProvider, bcryptCo
 
 	if as.Revision() == 0 {
 		as.commitRevision(tx)
-		as.saveConsistentIndex(tx)
 	}
 
 	as.setupMetricsReporter()

From 5a17367923ad599bb67f07dbf6e461892c243197 Mon Sep 17 00:00:00 2001
From: tangcong <tangcong506@gmail.com>
Date: Tue, 10 Mar 2020 10:56:33 +0800
Subject: [PATCH 3/3] etcdserver: print warn log when failed to apply request

---
 etcdserver/apply.go |  3 +++
 etcdserver/util.go  | 15 +++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/etcdserver/apply.go b/etcdserver/apply.go
index 25e50ebbb25..1838e331a9d 100644
--- a/etcdserver/apply.go
+++ b/etcdserver/apply.go
@@ -132,6 +132,9 @@ func (a *applierV3backend) Apply(r *pb.InternalRaftRequest) *applyResult {
 	ar := &applyResult{}
 	defer func(start time.Time) {
 		warnOfExpensiveRequest(a.s.getLogger(), start, &pb.InternalRaftStringer{Request: r}, ar.resp, ar.err)
+		if ar.err != nil {
+			warnOfFailedRequest(a.s.getLogger(), start, &pb.InternalRaftStringer{Request: r}, ar.resp, ar.err)
+		}
 	}(time.Now())
 
 	// call into a.s.applyV3.F instead of a.F so upper appliers can check individual calls
diff --git a/etcdserver/util.go b/etcdserver/util.go
index 609d1995994..883e14f0fb5 100644
--- a/etcdserver/util.go
+++ b/etcdserver/util.go
@@ -111,6 +111,21 @@ func warnOfExpensiveRequest(lg *zap.Logger, now time.Time, reqStringer fmt.Strin
 	warnOfExpensiveGenericRequest(lg, now, reqStringer, "", resp, err)
 }
 
+func warnOfFailedRequest(lg *zap.Logger, now time.Time, reqStringer fmt.Stringer, respMsg proto.Message, err error) {
+	var resp string
+	if !isNil(respMsg) {
+		resp = fmt.Sprintf("size:%d", proto.Size(respMsg))
+	}
+	d := time.Since(now)
+	lg.Warn(
+		"failed to apply request",
+		zap.Duration("took", d),
+		zap.String("request", reqStringer.String()),
+		zap.String("response", resp),
+		zap.Error(err),
+	)
+}
+
 func warnOfExpensiveReadOnlyTxnRequest(lg *zap.Logger, now time.Time, r *pb.TxnRequest, txnResponse *pb.TxnResponse, err error) {
 	reqStringer := pb.NewLoggableTxnRequest(r)
 	var resp string