| commit | b6841513379ea9ca503d1e350c5f93198fc2b03f | [log] [tgz] |
|---|---|---|
| author | xiaolong ran <rxl@apache.org> | Thu Aug 26 16:51:20 2021 +0800 |
| committer | GitHub <noreply@github.com> | Thu Aug 26 16:51:20 2021 +0800 |
| tree | e3802fce084675d4deeab77cb79fde167851d7db | |
| parent | 1a3ad70403aa04feda83edcfd984e25cef2dcfe6 [diff] |
Fix panic when scale down partitions (#601)
Signed-off-by: xiaolongran <xiaolongran@tencent.com>
### Motivation
When the program is running, if the business is forced to delete certain sub partitions, the following error message will be caused, that is, old_partitions is greater than new_partitions, it looks like it is doing scale down partitions, and the current code logic only deals with the scenario of scale up partitions , So if the user is forced to delete some sub partitions, the following error will be encountered:
```
level=info msg="[Changed number of partitions in topic]" new_partitions=1 old_partitions=20 topic="persistent://pulsar-xxxxxxx/xxxx/gxxxxxxxx"
```
```
panic: runtime error: index out of range [1] with length 1
goroutine 166288 [running]:
github.com/apache/pulsar-client-go/pulsar.(*producer).internalCreatePartitionsProducers(0xc0070aa6e0, 0x0, 0x0)
github.com/apache/pulsar-client-go/pulsar/producer_impl.go:194 +0x785
github.com/apache/pulsar-client-go/pulsar.(*producer).runBackgroundPartitionDiscovery.func1(0xc004167cd0, 0xc00559f5c0, 0xc006af6dc0, 0xc0070aa6e0)
github.com/apache/pulsar-client-go/pulsar/producer_impl.go:152 +0xce
created by github.com/apache/pulsar-client-go/pulsar.(*producer).runBackgroundPartitionDiscovery
github.com/apache/pulsar-client-go/pulsar/producer_impl.go:144 +0xcd
```
### Modifications
Increase the processing logic of scale down partition
A Go client library for the Apache Pulsar project.
This projects is developing a pure-Go client library for Pulsar that does not depend on the C++ Pulsar library.
Once feature parity and stability are reached, this will supersede the current CGo based library.
Check the Projects page at https://github.com/apache/pulsar-client-go/projects for tracking the status and the progress.
Import the client library:
import "github.com/apache/pulsar-client-go/pulsar"
Create a Producer:
client, err := pulsar.NewClient(pulsar.ClientOptions{
URL: "pulsar://localhost:6650",
})
defer client.Close()
producer, err := client.CreateProducer(pulsar.ProducerOptions{
Topic: "my-topic",
})
_, err = producer.Send(context.Background(), &pulsar.ProducerMessage{
Payload: []byte("hello"),
})
defer producer.Close()
if err != nil {
fmt.Println("Failed to publish message", err)
}
fmt.Println("Published message")
Create a Consumer:
client, err := pulsar.NewClient(pulsar.ClientOptions{
URL: "pulsar://localhost:6650",
})
defer client.Close()
consumer, err := client.Subscribe(pulsar.ConsumerOptions{
Topic: "my-topic",
SubscriptionName: "my-sub",
Type: pulsar.Shared,
})
defer consumer.Close()
msg, err := consumer.Receive(context.Background())
if err != nil {
log.Fatal(err)
}
fmt.Printf("Received message msgId: %#v -- content: '%s'\n",
msg.ID(), string(msg.Payload()))
Create a Reader:
client, err := pulsar.NewClient(pulsar.ClientOptions{URL: "pulsar://localhost:6650"})
if err != nil {
log.Fatal(err)
}
defer client.Close()
reader, err := client.CreateReader(pulsar.ReaderOptions{
Topic: "topic-1",
StartMessageID: pulsar.EarliestMessageID(),
})
if err != nil {
log.Fatal(err)
}
defer reader.Close()
for reader.HasNext() {
msg, err := reader.Next(context.Background())
if err != nil {
log.Fatal(err)
}
fmt.Printf("Received message msgId: %#v -- content: '%s'\n",
msg.ID(), string(msg.Payload()))
}
Contributions are welcomed and greatly appreciated. See CONTRIBUTING.md for details on submitting patches and the contribution workflow.
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