【BUG】【Producer】An additional partition is unintentionally created to partitioned topic.

[hozumi]

Hi, I found that a new partition is created when I send a message to partitioned-topic.

For example, when a partitioned topic have only one partition as following:

"persistent://mytenant/myns/mytopic-partition-0"

Sending message causes a new partition creation.

"persistent://mytenant/myns/mytopic-partition-0"
"persistent://mytenant/myns/mytopic-partition-1"

I think that the range wrongly include upper limit in the following line.

pulsar_sdk/lib/pulsar_sdk/protocol/partitioned.rb

Line 20 in 4973e56

(0..pmr.partitions).map do |i|

[archfish]

pmr.partitions is pulsar topic metadata returned from api.

if you only has one partitions, you can set partition to zero or keep empty.

[hozumi]

@archfish I'm still not sure why the number of partitions that returned from api needs to be changed manually.
The client library should be aware of the correct number of partitions in a topic and handle it automatically.
I think the range should exclude the upper limit to prevent the client library from accessing partitions that do not exist ( ... instead of .. ).

 (0...pmr.partitions).map do |i| 

[archfish]

Can you please provide me a code to reproduce.

[hozumi]

Here is a reproduce procedure.

1. set up a standalone pulsar.

$ docker run -it -p 6650:6650 -p 8080:8080 --mount source=pulsardata,target=/pulsar/data --mount source=pulsarconf,target=/pulsar/conf  apachepulsar/pulsar:2.8.0 bin/pulsar standalone --advertised-address 127.0.0.1

2. create a partitioned topic with 1 partition.

$ docker exec -it 3eef6a37e262 bin/pulsar-admin namespaces set-retention sample/ns1 --size 10M --time -1
$ docker exec -it 3eef6a37e262 bin/pulsar-admin topics create-partitioned-topic persistent://sample/ns1/myptopic --partitions 1
$ docker exec -it 3eef6a37e262 bin/pulsar-admin topics list sample/ns1
"persistent://sample/ns1/myptopic-partition-0"

3. produce a message into the partitioned topic.

require 'pulsar_sdk'

client = PulsarSdk.create_client(logical_addr: 'pulsar://127.0.0.1')
producer = PulsarSdk.create_producer(client, topic: 'persistent://sample/ns1/myptopic')

base_cmd = Pulsar::Proto::BaseCommand.new(
  type: Pulsar::Proto::BaseCommand::Type::SEND,
  send: Pulsar::Proto::CommandSend.new(
    num_messages: 1
  )
)
p_msg = PulsarSdk::Producer::Message.new("dang qian shi jian #{TimeX.now}")
producer.execute(base_cmd, p_msg)

4. check the results of topics list

% docker exec -it 3eef6a37e262 bin/pulsar-admin topics list sample/ns1
"persistent://sample/ns1/myptopic-partition-0"
"persistent://sample/ns1/myptopic-partition-1"

[archfish]

Thanks, I will look into it.