proxy: fix issue #1314

    Make sure *SCAN commands must be routed to master instances.

Author: spinlock

pkg/proxy/forward.go

@@ -215,7 +215,7 @@ func (d *forwardHelper) slotsmgrtExecWrapper(s *Slot, hkey []byte, database int3
 
 func (d *forwardHelper) forward2(s *Slot, r *Request) *BackendConn {
 	var database, seed = r.Database, r.Seed16()
-	if s.migrate.bc == nil && r.IsReadOnly() && len(s.replicaGroups) != 0 {
+	if s.migrate.bc == nil && !r.IsMasterOnly() && len(s.replicaGroups) != 0 {
 		for _, group := range s.replicaGroups {
 			var i = seed
 			for _ = range group {

pkg/proxy/mapper.go

@@ -37,13 +37,19 @@ func (f OpFlag) IsReadOnly() bool {
 	return (f & mask) == 0
 }
 
+func (f OpFlag) IsMasterOnly() bool {
+	const mask = FlagWrite | FlagMayWrite | FlagMasterOnly
+	return (f & mask) == 0
+}
+
 type OpInfo struct {
 	Name string
 	Flag OpFlag
 }
 
 const (
 	FlagWrite = 1 << iota
+	FlagMasterOnly
 	FlagMayWrite
 	FlagNotAllow
 )
@@ -104,7 +110,7 @@ func init() {
 		{"HLEN", 0},
 		{"HMGET", 0},
 		{"HMSET", FlagWrite},
-		{"HSCAN", 0},
+		{"HSCAN", FlagMasterOnly},
 		{"HSET", FlagWrite},
 		{"HSETNX", FlagWrite},
 		{"HSTRLEN", 0},
@@ -166,7 +172,7 @@ func init() {
 		{"RPUSHX", FlagWrite},
 		{"SADD", FlagWrite},
 		{"SAVE", FlagNotAllow},
-		{"SCAN", FlagNotAllow},
+		{"SCAN", FlagMasterOnly | FlagNotAllow},
 		{"SCARD", 0},
 		{"SCRIPT", FlagNotAllow},
 		{"SDIFF", 0},
@@ -185,7 +191,7 @@ func init() {
 		{"SLOTSCHECK", FlagNotAllow},
 		{"SLOTSDEL", FlagWrite | FlagNotAllow},
 		{"SLOTSHASHKEY", 0},
-		{"SLOTSINFO", 0},
+		{"SLOTSINFO", FlagMasterOnly},
 		{"SLOTSMAPPING", 0},
 		{"SLOTSMGRTONE", FlagWrite | FlagNotAllow},
 		{"SLOTSMGRTSLOT", FlagWrite | FlagNotAllow},
@@ -203,15 +209,15 @@ func init() {
 		{"SLOTSRESTORE-ASYNC", FlagWrite | FlagNotAllow},
 		{"SLOTSRESTORE-ASYNC-AUTH", FlagWrite | FlagNotAllow},
 		{"SLOTSRESTORE-ASYNC-ACK", FlagWrite | FlagNotAllow},
-		{"SLOTSSCAN", 0},
+		{"SLOTSSCAN", FlagMasterOnly},
 		{"SLOWLOG", FlagNotAllow},
 		{"SMEMBERS", 0},
 		{"SMOVE", FlagWrite},
 		{"SORT", FlagWrite},
 		{"SPOP", FlagWrite},
 		{"SRANDMEMBER", 0},
 		{"SREM", FlagWrite},
-		{"SSCAN", 0},
+		{"SSCAN", FlagMasterOnly},
 		{"STRLEN", 0},
 		{"SUBSCRIBE", FlagNotAllow},
 		{"SUBSTR", 0},
@@ -244,7 +250,7 @@ func init() {
 		{"ZREVRANGEBYLEX", 0},
 		{"ZREVRANGEBYSCORE", 0},
 		{"ZREVRANK", 0},
-		{"ZSCAN", 0},
+		{"ZSCAN", FlagMasterOnly},
 		{"ZSCORE", 0},
 		{"ZUNIONSTORE", FlagWrite},
 	} {