"ClusterClient.Ping().Result() error: got 4 elements in cluster info address, expected 2 or 3" when used for accessing redis cluster

[yuantingzhong]

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go-redis reports error when it is used to access redis-cluster

Expected Behavior

go-redis/redis should works well with redis cluster

Current Behavior

go-redis/redis ClusterClient.Ping().Result() reports error "got 4 elements in cluster info address, expected 2 or 3" (my redis cluster has six nodes)

Possible Solution

Steps to Reproduce

1. I build my redis cluster with docker and the redis's version is

"GOSU_VERSION=1.14",
"REDIS_VERSION=7.0.0",
"REDIS_DOWNLOAD_URL=http://download.redis.io/releases/redis-7.0.0.tar.gz",

and my go version is

# go version
go version go1.18.1 linux/amd64

2. I am sure my redis cluster works well, for example, I make a test with redis-cli as follows

root@hecs-18053-0002:/home/root/code/redis-cluster/cmd# docker run -it --rm redis redis-cli -c -h 192.168.0.28 -p 6700 -a 123456
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
192.168.0.28:6700> cluster nodes
27bfce46e99d870f7ca4ae5c51df30737581e0cf 192.168.0.180:6901@16901 master - 0 1651637749193 7 connected 0-5460
d93f9f77dc49e7177f6cadf6f32cd27e1ed4ead0 192.168.0.28:6900@16900 slave 27139ca982574acfb125a9d0421d99c47789f7c4 0 1651637750196 3 connected
c3c553a61c78fcdfd07ba6c72402f1d0a23bc006 192.168.0.141:6902@16902 slave f366d818f6c5cdf4ab7843ca8a14f39d58e0fa9d 0 1651637748189 2 connected
27139ca982574acfb125a9d0421d99c47789f7c4 192.168.0.141:6702@16702 master - 0 1651637748000 3 connected 10923-16383
fab30d84431b0e7cebdf0ed257b99e3192ba2d8d 192.168.0.28:6700@16700 myself,slave 27bfce46e99d870f7ca4ae5c51df30737581e0cf 0 1651637749000 7 connected
f366d818f6c5cdf4ab7843ca8a14f39d58e0fa9d 192.168.0.180:6701@16701 master - 0 1651637751199 2 connected 5461-10922
192.168.0.28:6700> cluster info
cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:6
cluster_size:3
cluster_current_epoch:7
cluster_my_epoch:7
cluster_stats_messages_ping_sent:45321
cluster_stats_messages_pong_sent:45740
cluster_stats_messages_sent:91061
cluster_stats_messages_ping_received:45740
cluster_stats_messages_pong_received:45321
cluster_stats_messages_update_received:5
cluster_stats_messages_received:91066
total_cluster_links_buffer_limit_exceeded:0
192.168.0.28:6700>
192.168.0.28:6700> keys *
1) "add"
2) "abb"
3) "bbb"
4) "kkkkkk"
5) "age"
6) "aac"
192.168.0.28:6700>

When I set or get key with redis-cli, it works well.
3. Then I test with a simple go program, as follows

package main

import (
        "context"
        "encoding/json"
        "fmt"
        "github.com/go-redis/redis/v8"
        "time"
)

func main() {
        rdb := redis.NewClusterClient(&redis.ClusterOptions{
                Password: "123456",
                Addrs: []string{"192.168.0.28:6700", "192.168.0.180:6701", "192.168.0.141:6702", "192.168.0.28:6900", "192.168.0.180:6901", "192.168.0.141:6902"},
        })

        _, err := rdb.Ping(context.Background()).Result()
        if err != nil {
                panic(err)
        }

        err = testString(rdb)
        if err != nil {
                panic(err)
        }
}

func testString(client *redis.ClusterClient) error {
        key := "mykey"
        err := client.Set(context.Background(), key, "myvalue", time.Minute).Err()
        if err != nil {
                fmt.Println("set err", err)
                return err
        }

        fmt.Println("--------------------------------------")
        for i := 0; i < 6; i++ {
                keyCnt, err := client.Exists(context.Background(), key).Result()
                if err != nil {
                        fmt.Println("client.Exists error: ", err)
                }
                fmt.Println("client.Exists val: ", keyCnt)

                val, err := client.Get(context.Background(), key).Result()
                if err != nil {
                        if err == redis.Nil { // key does not exist
                                fmt.Println("key not exist")
                        } else {
                                fmt.Println("Get err", err)
                                return err
                        }
                } else {
                        fmt.Printf("key: %v, value：%v\n", key, val)
                }

                time.Sleep(15 * time.Second)
        }

        return nil
}

build and run this program, it report error, as follows

# ./main
panic: got 4 elements in cluster info address, expected 2 or 3

goroutine 1 [running]:
main.main()
        /home/root/code/redis-cluster/cmd/main.go:19 +0x171

I think this is a bug, please check and fix it. Thank you very much！

Context (Environment)

Detailed Description

Possible Implementation

[UpwardGrowth]

Did you solve it, I have this problem too

[UpwardGrowth]

I guess you are using the latest redis version(7.x), I downgrade back to 6.x version solved the problem.

[md185331]

Hi what is the solution to this issue? What specific version tag works?

[lintanghui]

cluster slots cmd is not backwards-incompatible in redis-7.0, see detail at Clusterbus extensions and hostname support . the same issue #2082

[yuantingzhong]

Did you solve it, I have this problem too
Please downgrade back to redis 6.x version, I have tested with 6.2.7 and it works well.

[yuantingzhong]

I guess you are using the latest redis version(7.x), I downgrade back to 6.x version solved the problem.

Yes, you are right. Thank you.

[yuantingzhong]

Hi what is the solution to this issue? What specific version tag works?

I replaced redis 7.x with redis 6.x ，and it worked well.

[xs0910]

我也遇到了，降回6.2.5就OK了

[highsea]

我从 redis:7.0.2-alpine 回退到 6.2 ，确实不报错了，谢谢
docker pull redis:6.2-alpine3.16

PS:
redis7集群有报错： Unable to connect to redis cluster got 4 elements in cluster info address, expected 2 or 3

[vmihailenco]

Please use github.com/go-redis/redis/v9 with Redis 7

[mikhail-khalizev]

• post by mistake *

[SunGeolSong]

hello
in source

parse.go

info := ClusterSlotInfo{
Start: int(start),
End: int(end),
Addrs: make([]string, addrsn),
}

	fmt.Printf("clusterSlotInfoSliceParser info.Addrs %v \n", info.Addrs)

	for i := int64(0); i < addrsn; i++ {

		fmt.Printf("clusterSlotInfoSliceParser loop i: %d \n", i)

		n, err := readArrayHeader(cn)
		if err != nil {
			return nil, err
		}

		fmt.Printf("clusterSlotInfoSliceParser loop i: %d, n: %d \n", i, n)

		if n != 2 && n != 3 && n != 4 {
			err := fmt.Errorf("clusterSlotInfoSliceParser got222 %d elements in cluster info address, expected 2 or 3 o 4", n)
			return nil, err
		}

		ip, err := readStringReply(cn)
		if err != nil {
			return nil, err
		}

		fmt.Printf("clusterSlotInfoSliceParser loop i: %d, ip: %s \n", i, ip)

		port, err := readIntReply(cn)
		if err != nil {
			return nil, err
		}

		fmt.Printf("clusterSlotInfoSliceParser loop i: %d, port: %d \n", i, port)

		if n >= 3 {
			// TODO: expose id in ClusterSlotInfo
			_, err := readStringReply(cn)
			if err != nil {
				return nil, err
			}
                            // redis 7.2 show master cluster address : 5d1a898d77d...
		}

		if n == 4 {
                 
			s2, err := readArrayHeader(cn)
			if err != nil {
				fmt.Printf("clusterSlotInfoSliceParser loop i: %d, err: %v \n", i, err)

				return nil, err
			}

			fmt.Printf("clusterSlotInfoSliceParser loop i: %d, s2: %d \n", i, s2) // *0 mean 7.2 maybe end of array
		}

		info.Addrs[i] = net.JoinHostPort(ip, strconv.FormatInt(port, 10))
	}

reloadSlots begin
Process begin + CLUSTER info:
Process end
reloadSlots 1
ClusterSlots begin
ClusterSlots cmd : CLUSTER slots: []
Process begin + CLUSTER slots: []
parseArrayHeader line: [42 51], line: *3
parseArrayHeader line[1:]: [51], line: 3, n: 3
clusterSlotInfoSliceParser begin
clusterSlotInfoSliceParser begin infos: []
readArrayHeader begin
readArrayHeader line [42 51], str: *3
readArrayHeader line[0] 42, str: *
parseArrayHeader line: [42 51], line: *3
parseArrayHeader line[1:]: [51], line: 3, n: 3
clusterSlotInfoSliceParser 1 n: 3
clusterSlotInfoSliceParser 2 start: 0
clusterSlotInfoSliceParser 3 end: 5460
clusterSlotInfoSliceParser addrsn: 1
clusterSlotInfoSliceParser info.Addrs []
clusterSlotInfoSliceParser loop i: 0
readArrayHeader begin
readArrayHeader line [42 52], str: *4
readArrayHeader line[0] 42, str: *
parseArrayHeader line: [42 52], line: *4
parseArrayHeader line[1:]: [52], line: 4, n: 4
clusterSlotInfoSliceParser loop i: 0, n: 4
readStringReply - b : [49 56 51 46 49 49 49 46 49 54 52 46 49 57]
clusterSlotInfoSliceParser loop i: 0, ip: 127.0.0.1
clusterSlotInfoSliceParser loop i: 0, port: 6381
readArrayHeader begin
readArrayHeader line [42 48], str: *0 <-- n: 4 mean
readArrayHeader line[0] 42, str: *
parseArrayHeader line: [42 48], line: *0
parseArrayHeader line[1:]: [48], line: 0, n: 0
clusterSlotInfoSliceParser loop i: 0, s2: 0

[SunGeolSong]

info := ClusterSlotInfo{
Start: int(start),
End: int(end),
Addrs: make([]string, addrsn),
}

	for i := int64(0); i < addrsn; i++ {
		n, err := readArrayHeader(cn)
		if err != nil {
			return nil, err
		}
		//if n != 2 && n != 3 {
		if n != 2 && n != 3 && n != 4 {
			err := fmt.Errorf("got %d elements in cluster info address, expected 2 or 3 or 4", n)
			return nil, err
		}

		ip, err := readStringReply(cn)
		if err != nil {
			return nil, err
		}

		port, err := readIntReply(cn)
		if err != nil {
			return nil, err
		}

		//if n == 3 {
		if n >= 3 {
			// TODO: expose id in ClusterSlotInfo
			_, err := readStringReply(cn)
			if err != nil {
				return nil, err
			}
		}

		if n == 4 {
			// TODO: expose id in ClusterSlotInfo
			_, err := readArrayHeader(cn) // *0 end
			if err != nil {
				return nil, err
			}
		}

		info.Addrs[i] = net.JoinHostPort(ip, strconv.FormatInt(port, 10))
	}

[liudonghua123]

I also got panic: got 4 elements in cluster info address, expected 2 or 3 when I tried to use go-redis with the latest redis 7.2.3.
Since this is a known issues, why not update it or it has bean fixed?

[yangbodong22011]

The real fix PR for this issue is: #2108