Add ability for user to configure whether to fail fast on startup

[nerdBoi]

Application fails to connect to Pulsar; however, it swallows / logs the exception and does not restart

Is there anyway to add a configuration so that if a failure to connect to Pulsar happens on boot, it restarts?
For context this is what happened:
We applied a rolling restart to all of our applications
Spring Boot Pulsar Client tried to connect to pulsar; however, pulsar was not finished spinning up.
So, Pulsar just gave us back connection refused.

Error was like this:

java.util.concurrent.CompletionException: org.apache.pulsar.shade.io.netty.channel.AbstractChannel$AnnotatedConnectException: finishConnect(..) failed: Connection refused: \"},{\"attempt\":5,\"error\":\"java.util.concurrent.CompletionException: 
org.apache.pulsar.client.api.PulsarClientException: java.util.concurrent.CompletionException: org.apache.pulsar.shade.io.netty.channel.AbstractChannel$AnnotatedConnectException: finishConnect(..) failed: Connection refused: \"},{\"attempt\":6,\"error\":\"java.util.concurrent.CompletionException: 
org.apache.pulsar.client.api.PulsarClientException: java.util.concurrent.CompletionException: org.apache.pulsar.shade.io.netty.channel.AbstractChannel$AnnotatedConnectException: finishConnect(..) failed: Connection refused: \"}]}\n\tat org.apache.pulsar.client.api.PulsarClientException.unwrap(PulsarClientException.java:1074)\n\tat org.apache.pulsar.client.impl.ConsumerBuilderImpl.subscribe(ConsumerBuilderImpl.java:104)\n\tat 
org.springframework.pulsar.core.DefaultPulsarConsumerFactory.createConsumer(DefaultPulsarConsumerFactory.java:89)\n\tat org.springframework.pulsar.listener.DefaultPulsarMessageListenerContainer$Listener.<init>(DefaultPulsarMessageListenerContainer.java:298)\n\tat org.springframework.pulsar.listener.DefaultPulsarMessageListenerContainer.doStart(DefaultPulsarMessageListenerContainer.java:126)\n\tat org.springframework.pulsar.listener.AbstractPulsarMessageListenerContainer.start(AbstractPulsarMessageListenerContainer.java:110)\n\tat 

Final note, this is my first time submitting an issue on an open source project. If I goofed up just let me know please.

[onobc]

Hi @nerdBoi ,
First of all, your issue submission is just fine and thank you for taking the time to submit the issue. Much appreciated.

Currently the producer and consumers expect the successful connection to Pulsar up front. For the producer side (PulsarTemplate) it will throw the exception outward and the app will fail to start. However, the consumer (the @PulsarListener) containers have this buried down deeper and they let the app start eventhough there was an exception.

Connection retries

Longer term it would be nice if the client connect could be retried (more resilient). There is some work going on to enable #422 which may open the door for this ability (we will keep this in mind as we get further into that one).

FailFast Config Option

In the mean time, making the fail fast configurable and consistent would be helpful.

Also, out of curiosity, which version are you using?

[nerdBoi]

Awesome! I appreciate the swift reply and acknowledgement.

version: 0.2.0

I will follow: #422 going forward!

Yea the FailFast config option would be awesome to configure.
I think this is about it to the conversation?

Again, thanks for replying.

[onobc]

Note

This issue is about improving startup and it speaks of 2 features "Connection Retries" and "FailFast Config".

#816 has a similar theme but is only about "Connection Retries" (see original desc. As such, we will focus on "Connection Retries" in #816 and this ticket will solely be "Fail Fast Config".

cc: @eljefe6a