Replication factor is below 1 or larger than the number of available brokers.

[Lord-Y]

Version & Environment

Redpanda version: (use rpk version):

v21.10.1 (rev 8df2069e5b021a78fae75b5a4d534481d4d17f93)

Operating System (e.g. from /etc/os-release):

No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 21.10
Release:	21.10
Codename:	impish

• Docker (use docker info):

Client:
 Context:    default
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)
  buildx: Build with BuildKit (Docker Inc., v0.6.3-docker)
  scan: Docker Scan (Docker Inc., v0.9.0)

Server:
 Containers: 8
  Running: 3
  Paused: 0
  Stopped: 5
 Images: 3
 Server Version: 20.10.11
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 7b11cfaabd73bb80907dd23182b9347b4245eb5d
 runc version: v1.0.2-0-g52b36a2
 init version: de40ad0
 Security Options:
  apparmor
  seccomp
   Profile: default
  cgroupns
 Kernel Version: 5.13.0-21-generic
 Operating System: Ubuntu 21.10
 OSType: linux
 Architecture: x86_64
 CPUs: 16
 Total Memory: 31.32GiB
 Name: homebuntu
 ID: NOA3:MSGM:XFHN:LRDS:SON2:ZWBG:5LPQ:ACWF:DOJR:RYV7:HFZ7:RWIB
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

What went wrong?

Hello guys, following the documentation Setup a 3-node cluster I cannot create a topic with a replication factor of 2:

rpk topic create test -r 2 -p 1
TOPIC  STATUS
test   INVALID_REPLICATION_FACTOR: Replication factor is below 1 or larger than the number of available brokers.

I also tried this but of course no luck:

rpk topic create test -r 2 -p 1 --brokers 127.0.0.1:9092,127.0.0.1:9093,127.0.0.1:9094

rpk cluster info
BROKERS
=======
ID    HOST       PORT
0*    127.0.0.1  9092
1     127.0.0.1  9093
2     127.0.0.1  9094

rpk cluster metadata
BROKERS
=======
ID    HOST       PORT
0*    127.0.0.1  9092
1     127.0.0.1  9093
2     127.0.0.1  9094

Is it really a bug or am I doing something wrong?

[dotnwat]

hey @Lord-Y you'll need to use an odd number (-r 1 or -r 3) for the replication factor. The reason or this is our use of the quorum based replication protocol raft.

[Lord-Y]

@dotnwat Thx for the quick answer. It works :).

rpk topic create test -r 3 -p 1
TOPIC  STATUS
test   OK

rpk topic describe test
SUMMARY
=======
NAME        test
PARTITIONS  1
REPLICAS    3

CONFIGS
=======
KEY                     VALUE                          SOURCE
cleanup.policy          delete                         DYNAMIC_TOPIC_CONFIG
compression.type        producer                       DEFAULT_CONFIG
message.timestamp.type  CreateTime                     DEFAULT_CONFIG
partition_count         1                              DYNAMIC_TOPIC_CONFIG
redpanda.datapolicy     function_name:  script_name:   DEFAULT_CONFIG
replication_factor      3                              DYNAMIC_TOPIC_CONFIG
retention.bytes         -1                             DEFAULT_CONFIG
retention.ms            604800000                      DEFAULT_CONFIG
segment.bytes           1073741824                     DEFAULT_CONFIG

Do you want me to make a PR to add it in the troubleshooting section or in Set up a 3-node cluster or you to take care of it?
I'm sure others will ask for the same question.

[dotnwat]

Nice. Yes that does seem like something that should be in the docs as it is not obvious. I'd say it'd be safe to submit a PR that updates the troubleshooting section. I think it's debatable if it should go in the basic tutorial, but the docs reviewer can provide feedback on that.

[twmb]

We just added some clearer wording for negative partitions or too many partitions, we can extend that wording to cover this issue (see #4662, #4017)

[r-vasquez]

/backport v22.1.x