Dezhi,
Thank you for sharing this proposal. I have added this proposal to PIP-58 (
https://github.com/apache/pulsar/wiki/PIP-58-:-Support-Consumers--Set-Custom-Retry-Delay
).
+1 for this proposal since it is extending the capability of dead letter
policy.
Thanks,
Sijie
On Wed, Feb 26, 2020 at 7:05 AM dezhi liu <liudezhi2...@gmail.com> wrote:
> Hi all,
>
> Here is a suggest (PIP) on consumers can set custom retry delay when
> consumer fail.
>
>
> ------------
>
>
> PIP 58 : Support Consumers Set Custom Retry Delay
> ## Motivation
>
> For many online business systems, various exceptions usually occur in
> business logic processing, so the message needs to be re-consumed, but
> users hope that this delay time can be controlled flexibly. The current
> user's processing method is usually to send this message to a special retry
> topic, because production can specify any delay, so consumers subscribe the
> business topic and retry topic at the same time. I think this logic can be
> supported by pulsar itself, making it easier for users to use, and it looks
> like this is a very common requirement.
>
> ## Proposed changes
>
> This change can be supported on the client side, need to add a set of
> interfaces to org.apache.pulsar.client.api.Consumer
> ```java
> void reconsumeLater(Message<?> message, long delayTime, TimeUnit unit)
> throws PulsarClientException;
> CompletableFuture<Void> reconsumeLaterAsync(Message<?> message, long
> delayTime, TimeUnit unit);
> CompletableFuture<Void> reconsumeLaterAsync(Messages<?> messages, int
> delayLevel);
> CompletableFuture<Void> reconsumeLaterCumulativeAsync(Message<?> message,
> long delayTime, TimeUnit unit);
> ```
> DeadLetterPolicy add retry topic
> ```java
> public class DeadLetterPolicy {
>
> /**
> * Maximum number of times that a message will be redelivered before
> being sent to the dead letter queue.
> */
> private int maxRedeliverCount;
>
> /**
> * Name of the retry topic where the failing messages will be sent.
> */
> private String retryLetterTopic;
>
> /**
> * Name of the dead topic where the failing messages will be sent.
> */
> private String deadLetterTopic;
>
> }
>
> ```
> org.apache.pulsar.client.impl.ConsumerImpl add a retry producer
> ```java
> private volatile Producer<T> deadLetterProducer;
>
> private volatile Producer<T> retryLetterProducer;
> ```
> Can specify whether to enable retry when creating a consumer，default
> unenable
> ```java
> @Override
> public ConsumerBuilder<T> enableRetry(boolean retryEnable) {
> conf.setRetryEnable(retryEnable);
> return this;
> }
> ```
>
> ------------
>
>
> Thanks,
>
> Dezhi
>
