How to change replication-factor of topic

[DoubleLuck]

Hi all, I try to use sarama to increase replication-factor of topic , but didn't success, I need your help.

Versions

Sarama Version: 97315fe
Kafka Version: 1.0.0 (scala 2.12)
Go Version: 1.11 (windows/amd64)

Configuration

Sarama Config: config.Version = sarama.V1_0_0_0
Kafka Config: 3 brokers on local CentOS, id : 0 , 1, 2
Topic Info: test444 partition 1 replication-factor 1

	Topic: test444	PartitionCount:1	ReplicationFactor:1	Configs:
	Topic: test444	Partition: 0	Leader: 0	Replicas: 0	Isr: 0

I hava set sarama.Logger

	logger := log.New(os.Stderr, "[sarama] ", log.LstdFlags)
	sarama.Logger = logger

Step1

• refer: https://github.com/Shopify/sarama/blob/master/admin_test.go#L373-L385
• my code:

func Replication(topic string, replicationFactor int) error {
	rp := strconv.Itoa(replicationFactor)
	entries := make(map[string]*string)
	entries["ReplicationFactor"] = &rp
	err := admin.AlterConfig(sarama.TopicResource, topic, entries, false)
	if err != nil {
		beego.Error(err)
		return err
	}
	return nil
}

• kafka log:

org.apache.kafka.common.errors.InvalidConfigurationException: Unknown topic config name: ReplicationFactor

• sarama: no log

Step2

• refer: https://github.com/Shopify/sarama/blob/master/admin.go#L189-L222
• method:

clusterAdmin.CreatePartitions(topic string, count int32, assignment [][]int32, validateOnly bool)

• parameter: ("test444", 1, [[0, 1]], false)
• result: sarama return an error, no sarama log, no broker log

kafka server: Number of partitions is invalid.

• parameter: ("test444", 3, [[0, 1], [1,2], [2,0]], false)
• result: sarama return an error, no sarama log, no broker log

kafka server: Replica assignment is invalid.

• parameter: ("test444", 3, [[0, 1], [1,2]], false)
• result: sarama return an error, no sarama log, no broker log

kafka server: Replica assignment is invalid.

Maybe I pass wrong parameters or use incorrect configs, I didn't increase the replication-factor successfully. Please help me , THANK YOU!

[varun06]

Looks like it should work. Are you still facing this issue, if not, can you please close this issue?

[DoubleLuck]

Looks like it should work. Are you still facing this issue, if not, can you please close this issue?

I'm not working on this recently. I'll try later again, thanks.

[sladkoff]

I'd like to re-open this.

Getting the same error "Unknown topic config name: ReplicationFactor".

Sarama version: 1.26.0
Kafka version: 2.3.1
Go version: 1.13.0

[d1egoaz]

is this even supported by the kafka admin API?

[d1egoaz]

as far I know in order to change the replication factor you'll need to:

1. create a json file with the new replica assignments
2. use the kafka-reassign-partitions tools to execute the new plan

the sarama admin example is misleading, there is no support for changing a topic's replication factor on the fly

[d1egoaz]

@DoubleLuck @sladkoff I also have tested the CreatePartitions method.

It's working for me with:

err = admin.CreatePartitions(TestSinglePartitionTopic, 7, nil, false)
	if err != nil {

kafkacat -Lb localhost:9092
Metadata for all topics (from broker -1: localhost:9092/bootstrap):
 1 brokers:
  broker 1001 at kafka:9092 (controller)
 3 topics:
  topic "test.1.nokey" with 7 partitions:
    partition 0, leader 1001, replicas: 1001, isrs: 1001
    partition 1, leader 1001, replicas: 1001, isrs: 1001
    partition 2, leader 1001, replicas: 1001, isrs: 1001
    partition 3, leader 1001, replicas: 1001, isrs: 1001
    partition 4, leader 1001, replicas: 1001, isrs: 1001
    partition 5, leader 1001, replicas: 1001, isrs: 1001
    partition 6, leader 1001, replicas: 1001, isrs: 1001

or using and assignment plan:

number of brokers: 1
broker[0] id: 1001
current number of partitions: 1
current assignment: map[0:[1001]]

target: 4

You'll need to provide an assignment plan for the new partitions (3 new partitions)

	err = admin.CreatePartitions(TestSinglePartitionTopic, 4, [][]int32{{1001}, {1001}, {1001}}, false)
	if err != nil {
		fmt.Printf("   >>> kafkabridge_integration_test.go/: err: %T: %+v\n", err, err)
	}

current assignment after the change: map[0:[1001] 1:[1001] 2:[1001] 3:[1001]]

╰─○ kafkacat -Lb localhost:9092
Metadata for all topics (from broker -1: localhost:9092/bootstrap):
 1 brokers:
  broker 1001 at kafka:9092 (controller)
 3 topics:
  topic "test.1.nokey" with 4 partitions:
    partition 0, leader 1001, replicas: 1001, isrs: 1001
    partition 1, leader 1001, replicas: 1001, isrs: 1001
    partition 2, leader 1001, replicas: 1001, isrs: 1001
    partition 3, leader 1001, replicas: 1001, isrs: 1001

I think this could be in the docs, it's not straightforward to infer this, took me a bit no understand it.

[sladkoff]

@d1egoaz How can we use this to change the replica assignment for existing partitions? In your comment you create new partitions for the new assignment - your initial partition replication assignment is unchanged, isn't it?

Assume I have three broker IDS [1, 2, 3] and I have 3 partitions with replica assignment [1].

I want to update the assignment for these partitions to [1, 2, 3].

If I call CreatePartitions without increasing the partition count:

// assignment: [[1,2,3], [1,2,3], [1,2,3]]
admin.CreatePartitions("test-topic", 3, assignment, false)

I get error Number of partitions is invalid. - Topic already has 3 partitions.

I tried adding a new partition while also changing the replica assignment for all (now 4) partitions. Then I get the following error:

Replica assignment is invalid. - Increasing the number of partitions by 1 but 4 assignments provided.

It seems to me that it's only possible to set the replication assignment for new partitions which isn't sufficient. Can you verify this?

[sladkoff]

I'm assuming that the AlterPartitionReassignments needs to be implemented in order to edit assignments for existing partitions.

@d1egoaz I'd like to try and contribute this if you agree that this is the way to continue.

[d1egoaz]

That'd be awesome! go for it!