From 76a365937b7f96c8f57e6f2b1c39e68cc17b889a Mon Sep 17 00:00:00 2001
From: fanmin shi <fanmin.shi@coreos.com>
Date: Tue, 23 May 2017 17:50:20 -0700
Subject: [PATCH] etcdserver: add --max-ops-per-txn flag

Fixes #7826
---
 embed/config.go             | 1 +
 embed/etcd.go               | 1 +
 etcdmain/config.go          | 1 +
 etcdmain/help.go            | 2 ++
 etcdserver/api/v3rpc/key.go | 9 ++++++---
 etcdserver/config.go        | 1 +
 6 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/embed/config.go b/embed/config.go
index e3926f66cb4c..8a9d36b82864 100644
--- a/embed/config.go
+++ b/embed/config.go
@@ -85,6 +85,7 @@ type Config struct {
 	TickMs            uint  `json:"heartbeat-interval"`
 	ElectionMs        uint  `json:"election-timeout"`
 	QuotaBackendBytes int64 `json:"quota-backend-bytes"`
+	MaxOpsPerTxn      uint  `json:"max-ops-per-txn"`
 
 	// clustering
 
diff --git a/embed/etcd.go b/embed/etcd.go
index f77dee0e0656..5cbaaf44ea12 100644
--- a/embed/etcd.go
+++ b/embed/etcd.go
@@ -139,6 +139,7 @@ func StartEtcd(inCfg *Config) (e *Etcd, err error) {
 		ElectionTicks:           cfg.ElectionTicks(),
 		AutoCompactionRetention: cfg.AutoCompactionRetention,
 		QuotaBackendBytes:       cfg.QuotaBackendBytes,
+		MaxOpsPerTxn:            cfg.MaxOpsPerTxn,
 		StrictReconfigCheck:     cfg.StrictReconfigCheck,
 		ClientCertAuthEnabled:   cfg.ClientTLSInfo.ClientCertAuth,
 		AuthToken:               cfg.AuthToken,
diff --git a/etcdmain/config.go b/etcdmain/config.go
index b8732200ae60..33ae670490d1 100644
--- a/etcdmain/config.go
+++ b/etcdmain/config.go
@@ -138,6 +138,7 @@ func newConfig() *config {
 	fs.UintVar(&cfg.TickMs, "heartbeat-interval", cfg.TickMs, "Time (in milliseconds) of a heartbeat interval.")
 	fs.UintVar(&cfg.ElectionMs, "election-timeout", cfg.ElectionMs, "Time (in milliseconds) for an election to timeout.")
 	fs.Int64Var(&cfg.QuotaBackendBytes, "quota-backend-bytes", cfg.QuotaBackendBytes, "Raise alarms when backend size exceeds the given quota. 0 means use the default quota.")
+	fs.UintVar(&cfg.MaxOpsPerTxn, "max-ops-per-txn", cfg.MaxOpsPerTxn, "maximum operations per txn that etcd server allows (0 is unlimited); defaults to unlimited.")
 
 	// clustering
 	fs.Var(flags.NewURLsValue(embed.DefaultInitialAdvertisePeerURLs), "initial-advertise-peer-urls", "List of this member's peer URLs to advertise to the rest of the cluster.")
diff --git a/etcdmain/help.go b/etcdmain/help.go
index cd9282a3192d..cdec46baa4e5 100644
--- a/etcdmain/help.go
+++ b/etcdmain/help.go
@@ -66,6 +66,8 @@ member flags:
 		comma-separated whitelist of origins for CORS (cross-origin resource sharing).
 	--quota-backend-bytes '0'
 		raise alarms when backend size exceeds the given quota (0 defaults to low space quota).
+	--max-ops-per-txn '0' 
+		maximum operations per txn that etcd server allows (0 is unlimited); defaults to unlimited.
 
 clustering flags:
 
diff --git a/etcdserver/api/v3rpc/key.go b/etcdserver/api/v3rpc/key.go
index 8acae5983c06..639235565414 100644
--- a/etcdserver/api/v3rpc/key.go
+++ b/etcdserver/api/v3rpc/key.go
@@ -28,9 +28,11 @@ import (
 var (
 	plog = capnslog.NewPackageLogger("github.com/coreos/etcd", "etcdserver/api/v3rpc")
 
-	// Max operations per txn list. For example, Txn.Success can have at most 128 operations,
+	// MaxOpsPerTxn is the max operations per txn.
+	// e.g suppose maxOpsPerTxn = 128.
+	// Txn.Success can have at most 128 operations,
 	// and Txn.Failure can have at most 128 operations.
-	MaxOpsPerTxn = 128
+	MaxOpsPerTxn = 0
 )
 
 type kvServer struct {
@@ -39,6 +41,7 @@ type kvServer struct {
 }
 
 func NewKVServer(s *etcdserver.EtcdServer) pb.KVServer {
+	MaxOpsPerTxn = int(s.Cfg.MaxOpsPerTxn)
 	return &kvServer{hdr: newHeader(s), kv: s}
 }
 
@@ -151,7 +154,7 @@ func checkDeleteRequest(r *pb.DeleteRangeRequest) error {
 }
 
 func checkTxnRequest(r *pb.TxnRequest) error {
-	if len(r.Compare) > MaxOpsPerTxn || len(r.Success) > MaxOpsPerTxn || len(r.Failure) > MaxOpsPerTxn {
+	if (len(r.Compare) > MaxOpsPerTxn || len(r.Success) > MaxOpsPerTxn || len(r.Failure) > MaxOpsPerTxn) && MaxOpsPerTxn != 0 {
 		return rpctypes.ErrGRPCTooManyOps
 	}
 
diff --git a/etcdserver/config.go b/etcdserver/config.go
index 9c258934a1c0..2a609a995319 100644
--- a/etcdserver/config.go
+++ b/etcdserver/config.go
@@ -54,6 +54,7 @@ type ServerConfig struct {
 
 	AutoCompactionRetention int
 	QuotaBackendBytes       int64
+	MaxOpsPerTxn            uint
 
 	StrictReconfigCheck bool