clientv3: fix retry logic

1. Balancer should setup gRPC error code correctly for retry.

2. We should not mask context error.

clientv3/balancer.go

@@ -15,19 +15,19 @@
 package clientv3
 
 import (
-	"errors"
 	"net/url"
 	"strings"
 	"sync"
 
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 )
 
 // ErrNoAddrAvilable is returned by Get() when the balancer does not have
 // any active connection to endpoints at the time.
 // This error is returned only when opts.BlockingWait is true.
-var ErrNoAddrAvilable = errors.New("there is no address available")
+var ErrNoAddrAvilable = grpc.Errorf(codes.Unavailable, "there is no address available")
 
 // simpleBalancer does the bare minimum to expose multiple eps
 // to the grpc reconnection code path
@@ -173,9 +173,14 @@ func (b *simpleBalancer) Get(ctx context.Context, opts grpc.BalancerGetOptions)
 	// an address it has notified via Notify immediately instead of blocking.
 	if !opts.BlockingWait {
 		b.mu.RLock()
+		closed := b.closed
 		addr = b.pinAddr
 		upEps := len(b.upEps)
 		b.mu.RUnlock()
+		if closed {
+			return grpc.Address{Addr: ""}, nil, grpc.ErrClientConnClosing
+		}
+
 		if upEps == 0 {
 			return grpc.Address{Addr: ""}, nil, ErrNoAddrAvilable
 		}

clientv3/kv.go

@@ -125,6 +125,7 @@ func (kv *kv) Do(ctx context.Context, op Op) (OpResponse, error) {
 		if err == nil {
 			return resp, nil
 		}
+
 		if isHaltErr(ctx, err) {
 			return resp, toErr(ctx, err)
 		}

clientv3/retry.go

@@ -23,29 +23,32 @@ import (
 )
 
 type rpcFunc func(ctx context.Context) error
-type retryRpcFunc func(context.Context, rpcFunc)
+type retryRpcFunc func(context.Context, rpcFunc) error
 
 func (c *Client) newRetryWrapper() retryRpcFunc {
-	return func(rpcCtx context.Context, f rpcFunc) {
+	return func(rpcCtx context.Context, f rpcFunc) error {
 		for {
 			err := f(rpcCtx)
 			if err == nil {
-				return
+				return nil
 			}
+
 			// only retry if unavailable
 			if grpc.Code(err) != codes.Unavailable {
-				return
+				return err
 			}
 			// always stop retry on etcd errors
 			eErr := rpctypes.Error(err)
 			if _, ok := eErr.(rpctypes.EtcdError); ok {
-				return
+				return err
 			}
+
 			select {
 			case <-c.balancer.ConnectNotify():
 			case <-rpcCtx.Done():
+				return rpcCtx.Err()
 			case <-c.ctx.Done():
-				return
+				return c.ctx.Err()
 			}
 		}
 	}
@@ -62,7 +65,7 @@ func RetryKVClient(c *Client) pb.KVClient {
 }
 
 func (rkv *retryKVClient) Put(ctx context.Context, in *pb.PutRequest, opts ...grpc.CallOption) (resp *pb.PutResponse, err error) {
-	rkv.retryf(ctx, func(rctx context.Context) error {
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rkv.KVClient.Put(rctx, in, opts...)
 		return err
 	})
@@ -70,7 +73,7 @@ func (rkv *retryKVClient) Put(ctx context.Context, in *pb.PutRequest, opts ...gr
 }
 
 func (rkv *retryKVClient) DeleteRange(ctx context.Context, in *pb.DeleteRangeRequest, opts ...grpc.CallOption) (resp *pb.DeleteRangeResponse, err error) {
-	rkv.retryf(ctx, func(rctx context.Context) error {
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rkv.KVClient.DeleteRange(rctx, in, opts...)
 		return err
 	})
@@ -78,7 +81,7 @@ func (rkv *retryKVClient) DeleteRange(ctx context.Context, in *pb.DeleteRangeReq
 }
 
 func (rkv *retryKVClient) Txn(ctx context.Context, in *pb.TxnRequest, opts ...grpc.CallOption) (resp *pb.TxnResponse, err error) {
-	rkv.retryf(ctx, func(rctx context.Context) error {
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rkv.KVClient.Txn(rctx, in, opts...)
 		return err
 	})
@@ -86,7 +89,7 @@ func (rkv *retryKVClient) Txn(ctx context.Context, in *pb.TxnRequest, opts ...gr
 }
 
 func (rkv *retryKVClient) Compact(ctx context.Context, in *pb.CompactionRequest, opts ...grpc.CallOption) (resp *pb.CompactionResponse, err error) {
-	rkv.retryf(ctx, func(rctx context.Context) error {
+	err = rkv.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rkv.KVClient.Compact(rctx, in, opts...)
 		return err
 	})
@@ -104,7 +107,7 @@ func RetryLeaseClient(c *Client) pb.LeaseClient {
 }
 
 func (rlc *retryLeaseClient) LeaseGrant(ctx context.Context, in *pb.LeaseGrantRequest, opts ...grpc.CallOption) (resp *pb.LeaseGrantResponse, err error) {
-	rlc.retryf(ctx, func(rctx context.Context) error {
+	err = rlc.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rlc.LeaseClient.LeaseGrant(rctx, in, opts...)
 		return err
 	})
@@ -113,7 +116,7 @@ func (rlc *retryLeaseClient) LeaseGrant(ctx context.Context, in *pb.LeaseGrantRe
 }
 
 func (rlc *retryLeaseClient) LeaseRevoke(ctx context.Context, in *pb.LeaseRevokeRequest, opts ...grpc.CallOption) (resp *pb.LeaseRevokeResponse, err error) {
-	rlc.retryf(ctx, func(rctx context.Context) error {
+	err = rlc.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rlc.LeaseClient.LeaseRevoke(rctx, in, opts...)
 		return err
 	})
@@ -131,7 +134,7 @@ func RetryClusterClient(c *Client) pb.ClusterClient {
 }
 
 func (rcc *retryClusterClient) MemberAdd(ctx context.Context, in *pb.MemberAddRequest, opts ...grpc.CallOption) (resp *pb.MemberAddResponse, err error) {
-	rcc.retryf(ctx, func(rctx context.Context) error {
+	err = rcc.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rcc.ClusterClient.MemberAdd(rctx, in, opts...)
 		return err
 	})
@@ -139,7 +142,7 @@ func (rcc *retryClusterClient) MemberAdd(ctx context.Context, in *pb.MemberAddRe
 }
 
 func (rcc *retryClusterClient) MemberRemove(ctx context.Context, in *pb.MemberRemoveRequest, opts ...grpc.CallOption) (resp *pb.MemberRemoveResponse, err error) {
-	rcc.retryf(ctx, func(rctx context.Context) error {
+	err = rcc.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rcc.ClusterClient.MemberRemove(rctx, in, opts...)
 		return err
 	})
@@ -147,7 +150,7 @@ func (rcc *retryClusterClient) MemberRemove(ctx context.Context, in *pb.MemberRe
 }
 
 func (rcc *retryClusterClient) MemberUpdate(ctx context.Context, in *pb.MemberUpdateRequest, opts ...grpc.CallOption) (resp *pb.MemberUpdateResponse, err error) {
-	rcc.retryf(ctx, func(rctx context.Context) error {
+	err = rcc.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rcc.ClusterClient.MemberUpdate(rctx, in, opts...)
 		return err
 	})
@@ -165,7 +168,7 @@ func RetryAuthClient(c *Client) pb.AuthClient {
 }
 
 func (rac *retryAuthClient) AuthEnable(ctx context.Context, in *pb.AuthEnableRequest, opts ...grpc.CallOption) (resp *pb.AuthEnableResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.AuthEnable(rctx, in, opts...)
 		return err
 	})
@@ -173,7 +176,7 @@ func (rac *retryAuthClient) AuthEnable(ctx context.Context, in *pb.AuthEnableReq
 }
 
 func (rac *retryAuthClient) AuthDisable(ctx context.Context, in *pb.AuthDisableRequest, opts ...grpc.CallOption) (resp *pb.AuthDisableResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.AuthDisable(rctx, in, opts...)
 		return err
 	})
@@ -181,7 +184,7 @@ func (rac *retryAuthClient) AuthDisable(ctx context.Context, in *pb.AuthDisableR
 }
 
 func (rac *retryAuthClient) UserAdd(ctx context.Context, in *pb.AuthUserAddRequest, opts ...grpc.CallOption) (resp *pb.AuthUserAddResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.UserAdd(rctx, in, opts...)
 		return err
 	})
@@ -189,7 +192,7 @@ func (rac *retryAuthClient) UserAdd(ctx context.Context, in *pb.AuthUserAddReque
 }
 
 func (rac *retryAuthClient) UserDelete(ctx context.Context, in *pb.AuthUserDeleteRequest, opts ...grpc.CallOption) (resp *pb.AuthUserDeleteResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.UserDelete(rctx, in, opts...)
 		return err
 	})
@@ -197,7 +200,7 @@ func (rac *retryAuthClient) UserDelete(ctx context.Context, in *pb.AuthUserDelet
 }
 
 func (rac *retryAuthClient) UserChangePassword(ctx context.Context, in *pb.AuthUserChangePasswordRequest, opts ...grpc.CallOption) (resp *pb.AuthUserChangePasswordResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.UserChangePassword(rctx, in, opts...)
 		return err
 	})
@@ -205,7 +208,7 @@ func (rac *retryAuthClient) UserChangePassword(ctx context.Context, in *pb.AuthU
 }
 
 func (rac *retryAuthClient) UserGrantRole(ctx context.Context, in *pb.AuthUserGrantRoleRequest, opts ...grpc.CallOption) (resp *pb.AuthUserGrantRoleResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.UserGrantRole(rctx, in, opts...)
 		return err
 	})
@@ -213,7 +216,7 @@ func (rac *retryAuthClient) UserGrantRole(ctx context.Context, in *pb.AuthUserGr
 }
 
 func (rac *retryAuthClient) UserRevokeRole(ctx context.Context, in *pb.AuthUserRevokeRoleRequest, opts ...grpc.CallOption) (resp *pb.AuthUserRevokeRoleResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.UserRevokeRole(rctx, in, opts...)
 		return err
 	})
@@ -221,7 +224,7 @@ func (rac *retryAuthClient) UserRevokeRole(ctx context.Context, in *pb.AuthUserR
 }
 
 func (rac *retryAuthClient) RoleAdd(ctx context.Context, in *pb.AuthRoleAddRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleAddResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.RoleAdd(rctx, in, opts...)
 		return err
 	})
@@ -229,7 +232,7 @@ func (rac *retryAuthClient) RoleAdd(ctx context.Context, in *pb.AuthRoleAddReque
 }
 
 func (rac *retryAuthClient) RoleDelete(ctx context.Context, in *pb.AuthRoleDeleteRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleDeleteResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.RoleDelete(rctx, in, opts...)
 		return err
 	})
@@ -237,7 +240,7 @@ func (rac *retryAuthClient) RoleDelete(ctx context.Context, in *pb.AuthRoleDelet
 }
 
 func (rac *retryAuthClient) RoleGrantPermission(ctx context.Context, in *pb.AuthRoleGrantPermissionRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleGrantPermissionResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.RoleGrantPermission(rctx, in, opts...)
 		return err
 	})
@@ -245,7 +248,7 @@ func (rac *retryAuthClient) RoleGrantPermission(ctx context.Context, in *pb.Auth
 }
 
 func (rac *retryAuthClient) RoleRevokePermission(ctx context.Context, in *pb.AuthRoleRevokePermissionRequest, opts ...grpc.CallOption) (resp *pb.AuthRoleRevokePermissionResponse, err error) {
-	rac.retryf(ctx, func(rctx context.Context) error {
+	err = rac.retryf(ctx, func(rctx context.Context) error {
 		resp, err = rac.AuthClient.RoleRevokePermission(rctx, in, opts...)
 		return err
 	})