forked from redis/go-redis
-
Notifications
You must be signed in to change notification settings - Fork 0
/
cluster.go
1672 lines (1411 loc) · 34 KB
/
cluster.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
package redis
import (
"context"
"crypto/tls"
"fmt"
"math"
"math/rand"
"net"
"runtime"
"sort"
"sync"
"sync/atomic"
"time"
"github.com/go-redis/redis/v7/internal"
"github.com/go-redis/redis/v7/internal/hashtag"
"github.com/go-redis/redis/v7/internal/pool"
"github.com/go-redis/redis/v7/internal/proto"
)
var errClusterNoNodes = fmt.Errorf("redis: cluster has no nodes")
// ClusterOptions are used to configure a cluster client and should be
// passed to NewClusterClient.
type ClusterOptions struct {
// A seed list of host:port addresses of cluster nodes.
Addrs []string
// The maximum number of retries before giving up. Command is retried
// on network errors and MOVED/ASK redirects.
// Default is 8 retries.
MaxRedirects int
// Enables read-only commands on slave nodes.
ReadOnly bool
// Allows routing read-only commands to the closest master or slave node.
// It automatically enables ReadOnly.
RouteByLatency bool
// Allows routing read-only commands to the random master or slave node.
// It automatically enables ReadOnly.
RouteRandomly bool
// Optional function that returns cluster slots information.
// It is useful to manually create cluster of standalone Redis servers
// and load-balance read/write operations between master and slaves.
// It can use service like ZooKeeper to maintain configuration information
// and Cluster.ReloadState to manually trigger state reloading.
ClusterSlots func() ([]ClusterSlot, error)
// Optional hook that is called when a new node is created.
OnNewNode func(*Client)
// Following options are copied from Options struct.
Dialer func(ctx context.Context, network, addr string) (net.Conn, error)
OnConnect func(*Conn) error
Password string
MaxRetries int
MinRetryBackoff time.Duration
MaxRetryBackoff time.Duration
DialTimeout time.Duration
ReadTimeout time.Duration
WriteTimeout time.Duration
// PoolSize applies per cluster node and not for the whole cluster.
PoolSize int
MinIdleConns int
MaxConnAge time.Duration
PoolTimeout time.Duration
IdleTimeout time.Duration
IdleCheckFrequency time.Duration
TLSConfig *tls.Config
}
func (opt *ClusterOptions) init() {
if opt.MaxRedirects == -1 {
opt.MaxRedirects = 0
} else if opt.MaxRedirects == 0 {
opt.MaxRedirects = 8
}
if (opt.RouteByLatency || opt.RouteRandomly) && opt.ClusterSlots == nil {
opt.ReadOnly = true
}
if opt.PoolSize == 0 {
opt.PoolSize = 5 * runtime.NumCPU()
}
switch opt.ReadTimeout {
case -1:
opt.ReadTimeout = 0
case 0:
opt.ReadTimeout = 3 * time.Second
}
switch opt.WriteTimeout {
case -1:
opt.WriteTimeout = 0
case 0:
opt.WriteTimeout = opt.ReadTimeout
}
switch opt.MinRetryBackoff {
case -1:
opt.MinRetryBackoff = 0
case 0:
opt.MinRetryBackoff = 8 * time.Millisecond
}
switch opt.MaxRetryBackoff {
case -1:
opt.MaxRetryBackoff = 0
case 0:
opt.MaxRetryBackoff = 512 * time.Millisecond
}
}
func (opt *ClusterOptions) clientOptions() *Options {
const disableIdleCheck = -1
return &Options{
Dialer: opt.Dialer,
OnConnect: opt.OnConnect,
MaxRetries: opt.MaxRetries,
MinRetryBackoff: opt.MinRetryBackoff,
MaxRetryBackoff: opt.MaxRetryBackoff,
Password: opt.Password,
readOnly: opt.ReadOnly,
DialTimeout: opt.DialTimeout,
ReadTimeout: opt.ReadTimeout,
WriteTimeout: opt.WriteTimeout,
PoolSize: opt.PoolSize,
MinIdleConns: opt.MinIdleConns,
MaxConnAge: opt.MaxConnAge,
PoolTimeout: opt.PoolTimeout,
IdleTimeout: opt.IdleTimeout,
IdleCheckFrequency: disableIdleCheck,
TLSConfig: opt.TLSConfig,
}
}
//------------------------------------------------------------------------------
type clusterNode struct {
Client *Client
latency uint32 // atomic
generation uint32 // atomic
failing uint32 // atomic
}
func newClusterNode(clOpt *ClusterOptions, addr string) *clusterNode {
opt := clOpt.clientOptions()
opt.Addr = addr
node := clusterNode{
Client: NewClient(opt),
}
node.latency = math.MaxUint32
if clOpt.RouteByLatency {
go node.updateLatency()
}
if clOpt.OnNewNode != nil {
clOpt.OnNewNode(node.Client)
}
return &node
}
func (n *clusterNode) String() string {
return n.Client.String()
}
func (n *clusterNode) Close() error {
return n.Client.Close()
}
func (n *clusterNode) updateLatency() {
const probes = 10
var latency uint32
for i := 0; i < probes; i++ {
start := time.Now()
n.Client.Ping(context.TODO())
probe := uint32(time.Since(start) / time.Microsecond)
latency = (latency + probe) / 2
}
atomic.StoreUint32(&n.latency, latency)
}
func (n *clusterNode) Latency() time.Duration {
latency := atomic.LoadUint32(&n.latency)
return time.Duration(latency) * time.Microsecond
}
func (n *clusterNode) MarkAsFailing() {
atomic.StoreUint32(&n.failing, uint32(time.Now().Unix()))
}
func (n *clusterNode) Failing() bool {
const timeout = 15 // 15 seconds
failing := atomic.LoadUint32(&n.failing)
if failing == 0 {
return false
}
if time.Now().Unix()-int64(failing) < timeout {
return true
}
atomic.StoreUint32(&n.failing, 0)
return false
}
func (n *clusterNode) Generation() uint32 {
return atomic.LoadUint32(&n.generation)
}
func (n *clusterNode) SetGeneration(gen uint32) {
for {
v := atomic.LoadUint32(&n.generation)
if gen < v || atomic.CompareAndSwapUint32(&n.generation, v, gen) {
break
}
}
}
//------------------------------------------------------------------------------
type clusterNodes struct {
opt *ClusterOptions
mu sync.RWMutex
allAddrs []string
allNodes map[string]*clusterNode
clusterAddrs []string
closed bool
_generation uint32 // atomic
}
func newClusterNodes(opt *ClusterOptions) *clusterNodes {
return &clusterNodes{
opt: opt,
allAddrs: opt.Addrs,
allNodes: make(map[string]*clusterNode),
}
}
func (c *clusterNodes) Close() error {
c.mu.Lock()
defer c.mu.Unlock()
if c.closed {
return nil
}
c.closed = true
var firstErr error
for _, node := range c.allNodes {
if err := node.Client.Close(); err != nil && firstErr == nil {
firstErr = err
}
}
c.allNodes = nil
c.clusterAddrs = nil
return firstErr
}
func (c *clusterNodes) Addrs() ([]string, error) {
var addrs []string
c.mu.RLock()
closed := c.closed
if !closed {
if len(c.clusterAddrs) > 0 {
addrs = c.clusterAddrs
} else {
addrs = c.allAddrs
}
}
c.mu.RUnlock()
if closed {
return nil, pool.ErrClosed
}
if len(addrs) == 0 {
return nil, errClusterNoNodes
}
return addrs, nil
}
func (c *clusterNodes) NextGeneration() uint32 {
return atomic.AddUint32(&c._generation, 1)
}
// GC removes unused nodes.
func (c *clusterNodes) GC(generation uint32) {
//nolint:prealloc
var collected []*clusterNode
c.mu.Lock()
for addr, node := range c.allNodes {
if node.Generation() >= generation {
continue
}
c.clusterAddrs = remove(c.clusterAddrs, addr)
delete(c.allNodes, addr)
collected = append(collected, node)
}
c.mu.Unlock()
for _, node := range collected {
_ = node.Client.Close()
}
}
func (c *clusterNodes) Get(addr string) (*clusterNode, error) {
node, err := c.get(addr)
if err != nil {
return nil, err
}
if node != nil {
return node, nil
}
c.mu.Lock()
defer c.mu.Unlock()
if c.closed {
return nil, pool.ErrClosed
}
node, ok := c.allNodes[addr]
if ok {
return node, err
}
node = newClusterNode(c.opt, addr)
c.allAddrs = appendIfNotExists(c.allAddrs, addr)
c.clusterAddrs = append(c.clusterAddrs, addr)
c.allNodes[addr] = node
return node, err
}
func (c *clusterNodes) get(addr string) (*clusterNode, error) {
var node *clusterNode
var err error
c.mu.RLock()
if c.closed {
err = pool.ErrClosed
} else {
node = c.allNodes[addr]
}
c.mu.RUnlock()
return node, err
}
func (c *clusterNodes) All() ([]*clusterNode, error) {
c.mu.RLock()
defer c.mu.RUnlock()
if c.closed {
return nil, pool.ErrClosed
}
cp := make([]*clusterNode, 0, len(c.allNodes))
for _, node := range c.allNodes {
cp = append(cp, node)
}
return cp, nil
}
func (c *clusterNodes) Random() (*clusterNode, error) {
addrs, err := c.Addrs()
if err != nil {
return nil, err
}
n := rand.Intn(len(addrs))
return c.Get(addrs[n])
}
//------------------------------------------------------------------------------
type clusterSlot struct {
start, end int
nodes []*clusterNode
}
type clusterSlotSlice []*clusterSlot
func (p clusterSlotSlice) Len() int {
return len(p)
}
func (p clusterSlotSlice) Less(i, j int) bool {
return p[i].start < p[j].start
}
func (p clusterSlotSlice) Swap(i, j int) {
p[i], p[j] = p[j], p[i]
}
type clusterState struct {
nodes *clusterNodes
Masters []*clusterNode
Slaves []*clusterNode
slots []*clusterSlot
generation uint32
createdAt time.Time
}
func newClusterState(
nodes *clusterNodes, slots []ClusterSlot, origin string,
) (*clusterState, error) {
c := clusterState{
nodes: nodes,
slots: make([]*clusterSlot, 0, len(slots)),
generation: nodes.NextGeneration(),
createdAt: time.Now(),
}
originHost, _, _ := net.SplitHostPort(origin)
isLoopbackOrigin := isLoopback(originHost)
for _, slot := range slots {
var nodes []*clusterNode
for i, slotNode := range slot.Nodes {
addr := slotNode.Addr
if !isLoopbackOrigin {
addr = replaceLoopbackHost(addr, originHost)
}
node, err := c.nodes.Get(addr)
if err != nil {
return nil, err
}
node.SetGeneration(c.generation)
nodes = append(nodes, node)
if i == 0 {
c.Masters = appendUniqueNode(c.Masters, node)
} else {
c.Slaves = appendUniqueNode(c.Slaves, node)
}
}
c.slots = append(c.slots, &clusterSlot{
start: slot.Start,
end: slot.End,
nodes: nodes,
})
}
sort.Sort(clusterSlotSlice(c.slots))
time.AfterFunc(time.Minute, func() {
nodes.GC(c.generation)
})
return &c, nil
}
func replaceLoopbackHost(nodeAddr, originHost string) string {
nodeHost, nodePort, err := net.SplitHostPort(nodeAddr)
if err != nil {
return nodeAddr
}
nodeIP := net.ParseIP(nodeHost)
if nodeIP == nil {
return nodeAddr
}
if !nodeIP.IsLoopback() {
return nodeAddr
}
// Use origin host which is not loopback and node port.
return net.JoinHostPort(originHost, nodePort)
}
func isLoopback(host string) bool {
ip := net.ParseIP(host)
if ip == nil {
return true
}
return ip.IsLoopback()
}
func (c *clusterState) slotMasterNode(slot int) (*clusterNode, error) {
nodes := c.slotNodes(slot)
if len(nodes) > 0 {
return nodes[0], nil
}
return c.nodes.Random()
}
func (c *clusterState) slotSlaveNode(slot int) (*clusterNode, error) {
nodes := c.slotNodes(slot)
switch len(nodes) {
case 0:
return c.nodes.Random()
case 1:
return nodes[0], nil
case 2:
if slave := nodes[1]; !slave.Failing() {
return slave, nil
}
return nodes[0], nil
default:
var slave *clusterNode
for i := 0; i < 10; i++ {
n := rand.Intn(len(nodes)-1) + 1
slave = nodes[n]
if !slave.Failing() {
return slave, nil
}
}
// All slaves are loading - use master.
return nodes[0], nil
}
}
func (c *clusterState) slotClosestNode(slot int) (*clusterNode, error) {
const threshold = time.Millisecond
nodes := c.slotNodes(slot)
if len(nodes) == 0 {
return c.nodes.Random()
}
var node *clusterNode
for _, n := range nodes {
if n.Failing() {
continue
}
if node == nil || node.Latency()-n.Latency() > threshold {
node = n
}
}
return node, nil
}
func (c *clusterState) slotRandomNode(slot int) (*clusterNode, error) {
nodes := c.slotNodes(slot)
if len(nodes) == 0 {
return c.nodes.Random()
}
n := rand.Intn(len(nodes))
return nodes[n], nil
}
func (c *clusterState) slotNodes(slot int) []*clusterNode {
i := sort.Search(len(c.slots), func(i int) bool {
return c.slots[i].end >= slot
})
if i >= len(c.slots) {
return nil
}
x := c.slots[i]
if slot >= x.start && slot <= x.end {
return x.nodes
}
return nil
}
//------------------------------------------------------------------------------
type clusterStateHolder struct {
load func(ctx context.Context) (*clusterState, error)
state atomic.Value
reloading uint32 // atomic
}
func newClusterStateHolder(fn func(ctx context.Context) (*clusterState, error)) *clusterStateHolder {
return &clusterStateHolder{
load: fn,
}
}
func (c *clusterStateHolder) Reload(ctx context.Context) (*clusterState, error) {
state, err := c.load(ctx)
if err != nil {
return nil, err
}
c.state.Store(state)
return state, nil
}
func (c *clusterStateHolder) LazyReload(ctx context.Context) {
if !atomic.CompareAndSwapUint32(&c.reloading, 0, 1) {
return
}
go func() {
defer atomic.StoreUint32(&c.reloading, 0)
_, err := c.Reload(ctx)
if err != nil {
return
}
time.Sleep(100 * time.Millisecond)
}()
}
func (c *clusterStateHolder) Get(ctx context.Context) (*clusterState, error) {
v := c.state.Load()
if v != nil {
state := v.(*clusterState)
if time.Since(state.createdAt) > time.Minute {
c.LazyReload(ctx)
}
return state, nil
}
return c.Reload(ctx)
}
func (c *clusterStateHolder) ReloadOrGet(ctx context.Context) (*clusterState, error) {
state, err := c.Reload(ctx)
if err == nil {
return state, nil
}
return c.Get(ctx)
}
//------------------------------------------------------------------------------
type clusterClient struct {
opt *ClusterOptions
nodes *clusterNodes
state *clusterStateHolder //nolint:structcheck
cmdsInfoCache *cmdsInfoCache //nolint:structcheck
}
// ClusterClient is a Redis Cluster client representing a pool of zero
// or more underlying connections. It's safe for concurrent use by
// multiple goroutines.
type ClusterClient struct {
*clusterClient
cmdable
hooks
ctx context.Context
}
// NewClusterClient returns a Redis Cluster client as described in
// http://redis.io/topics/cluster-spec.
func NewClusterClient(opt *ClusterOptions) *ClusterClient {
opt.init()
c := &ClusterClient{
clusterClient: &clusterClient{
opt: opt,
nodes: newClusterNodes(opt),
},
ctx: context.Background(),
}
c.state = newClusterStateHolder(c.loadState)
c.cmdsInfoCache = newCmdsInfoCache(c.cmdsInfo)
c.cmdable = c.Process
if opt.IdleCheckFrequency > 0 {
go c.reaper(opt.IdleCheckFrequency)
}
return c
}
func (c *ClusterClient) Context() context.Context {
return c.ctx
}
func (c *ClusterClient) WithContext(ctx context.Context) *ClusterClient {
if ctx == nil {
panic("nil context")
}
clone := *c
clone.cmdable = clone.Process
clone.hooks.lock()
clone.ctx = ctx
return &clone
}
// Options returns read-only Options that were used to create the client.
func (c *ClusterClient) Options() *ClusterOptions {
return c.opt
}
// ReloadState reloads cluster state. If available it calls ClusterSlots func
// to get cluster slots information.
func (c *ClusterClient) ReloadState(ctx context.Context) error {
_, err := c.state.Reload(ctx)
return err
}
// Close closes the cluster client, releasing any open resources.
//
// It is rare to Close a ClusterClient, as the ClusterClient is meant
// to be long-lived and shared between many goroutines.
func (c *ClusterClient) Close() error {
return c.nodes.Close()
}
// Do creates a Cmd from the args and processes the cmd.
func (c *ClusterClient) Do(ctx context.Context, args ...interface{}) *Cmd {
cmd := NewCmd(ctx, args...)
_ = c.Process(ctx, cmd)
return cmd
}
func (c *ClusterClient) Process(ctx context.Context, cmd Cmder) error {
return c.hooks.process(ctx, cmd, c.process)
}
func (c *ClusterClient) process(ctx context.Context, cmd Cmder) error {
err := c._process(ctx, cmd)
if err != nil {
cmd.SetErr(err)
return err
}
return nil
}
func (c *ClusterClient) _process(ctx context.Context, cmd Cmder) error {
cmdInfo := c.cmdInfo(cmd.Name())
slot := c.cmdSlot(cmd)
var node *clusterNode
var ask bool
var lastErr error
for attempt := 0; attempt <= c.opt.MaxRedirects; attempt++ {
if attempt > 0 {
if err := internal.Sleep(ctx, c.retryBackoff(attempt)); err != nil {
return err
}
}
if node == nil {
var err error
node, err = c.cmdNode(ctx, cmdInfo, slot)
if err != nil {
return err
}
}
if ask {
pipe := node.Client.Pipeline()
_ = pipe.Process(ctx, NewCmd(ctx, "asking"))
_ = pipe.Process(ctx, cmd)
_, lastErr = pipe.Exec(ctx)
_ = pipe.Close()
ask = false
} else {
lastErr = node.Client.Process(ctx, cmd)
}
// If there is no error - we are done.
if lastErr == nil {
return nil
}
if lastErr != Nil {
c.state.LazyReload(ctx)
}
if lastErr == pool.ErrClosed || isReadOnlyError(lastErr) {
node = nil
continue
}
// If slave is loading - pick another node.
if c.opt.ReadOnly && isLoadingError(lastErr) {
node.MarkAsFailing()
node = nil
continue
}
var moved bool
var addr string
moved, ask, addr = isMovedError(lastErr)
if moved || ask {
var err error
node, err = c.nodes.Get(addr)
if err != nil {
return err
}
continue
}
if isRetryableError(lastErr, cmd.readTimeout() == nil) {
// First retry the same node.
if attempt == 0 {
continue
}
// Second try another node.
node.MarkAsFailing()
node = nil
continue
}
return lastErr
}
return lastErr
}
// ForEachMaster concurrently calls the fn on each master node in the cluster.
// It returns the first error if any.
func (c *ClusterClient) ForEachMaster(
ctx context.Context,
fn func(ctx context.Context, client *Client) error,
) error {
state, err := c.state.ReloadOrGet(ctx)
if err != nil {
return err
}
var wg sync.WaitGroup
errCh := make(chan error, 1)
for _, master := range state.Masters {
wg.Add(1)
go func(node *clusterNode) {
defer wg.Done()
err := fn(ctx, node.Client)
if err != nil {
select {
case errCh <- err:
default:
}
}
}(master)
}
wg.Wait()
select {
case err := <-errCh:
return err
default:
return nil
}
}
// ForEachSlave concurrently calls the fn on each slave node in the cluster.
// It returns the first error if any.
func (c *ClusterClient) ForEachSlave(
ctx context.Context,
fn func(ctx context.Context, client *Client) error,
) error {
state, err := c.state.ReloadOrGet(ctx)
if err != nil {
return err
}
var wg sync.WaitGroup
errCh := make(chan error, 1)
for _, slave := range state.Slaves {
wg.Add(1)
go func(node *clusterNode) {
defer wg.Done()
err := fn(ctx, node.Client)
if err != nil {
select {
case errCh <- err:
default:
}
}
}(slave)
}
wg.Wait()
select {
case err := <-errCh:
return err
default:
return nil
}
}
// ForEachNode concurrently calls the fn on each known node in the cluster.
// It returns the first error if any.
func (c *ClusterClient) ForEachNode(
ctx context.Context,
fn func(ctx context.Context, client *Client) error,
) error {
state, err := c.state.ReloadOrGet(ctx)
if err != nil {
return err
}
var wg sync.WaitGroup
errCh := make(chan error, 1)
worker := func(node *clusterNode) {
defer wg.Done()
err := fn(ctx, node.Client)
if err != nil {
select {
case errCh <- err:
default:
}
}
}
for _, node := range state.Masters {
wg.Add(1)
go worker(node)
}
for _, node := range state.Slaves {
wg.Add(1)
go worker(node)
}
wg.Wait()
select {
case err := <-errCh:
return err
default:
return nil
}
}
// PoolStats returns accumulated connection pool stats.
func (c *ClusterClient) PoolStats() *PoolStats {
var acc PoolStats
state, _ := c.state.Get(context.TODO())
if state == nil {
return &acc
}
for _, node := range state.Masters {
s := node.Client.connPool.Stats()
acc.Hits += s.Hits
acc.Misses += s.Misses
acc.Timeouts += s.Timeouts
acc.TotalConns += s.TotalConns
acc.IdleConns += s.IdleConns
acc.StaleConns += s.StaleConns
}
for _, node := range state.Slaves {
s := node.Client.connPool.Stats()
acc.Hits += s.Hits
acc.Misses += s.Misses
acc.Timeouts += s.Timeouts
acc.TotalConns += s.TotalConns
acc.IdleConns += s.IdleConns
acc.StaleConns += s.StaleConns
}
return &acc
}
func (c *ClusterClient) loadState(ctx context.Context) (*clusterState, error) {
if c.opt.ClusterSlots != nil {
slots, err := c.opt.ClusterSlots()
if err != nil {
return nil, err
}
return newClusterState(c.nodes, slots, "")
}
addrs, err := c.nodes.Addrs()
if err != nil {
return nil, err
}
var firstErr error
for _, addr := range addrs {
node, err := c.nodes.Get(addr)
if err != nil {
if firstErr == nil {
firstErr = err
}
continue