[MINOR] Fix documentation of parameter "block.on.buffer.full"

[mjsax]

default value is "false" and not "true"

See: https://stackoverflow.com/questions/35578519/kafka-block-on-buffer-full-default-value
and

kafka/clients/src/main/java/org/apache/kafka/clients/producer/ProducerConfig.java

Line 232 in d5b43b1

.define(BLOCK_ON_BUFFER_FULL_CONFIG, Type.BOOLEAN, false, Importance.LOW, BLOCK_ON_BUFFER_FULL_DOC)

[ijuma]

The javadoc for this config says:

This config will be removed in a future release. Also, the {@link #METADATA_FETCH_TIMEOUT_CONFIG} is no longer honored when this property is set to true.

It may be worth including that in the actual text. Going forward, MAX_BLOCK_MS_CONFIG should be used instead.

[mjsax]

@ijuma thanks for the review. I just updated this PR. I did not squash both commits on purpose (if you want me to squash them, just let me know.)

[ijuma]

LGTM cc @gwenshap

[granthenke]

Could use the parameter variable here. METADATA_FETCH_TIMEOUT_CONFIG

[mjsax]

Thanks for your comments @granthenke Unfortunately, I get an compile error I do not understand... (I commented your comment...)

Btw: I had a look through the whole file, and there are some more thing we could improve.

1. use BATCH_SIZE_CONFIG instead of "batch.size" in LINGER_MS_DOC
2. use LINGER_MS_CONFIG instead of "linger.ms" in LINGER_MS_DOC
3. replace {@link KafkaProducer#send()} with <code>KafkaProducer.send()<code> in MAX_BLOCK_MS_DOC (JavaDoc markup does not work here...)
4. replace {@link KafkaProducer#partitionsFor} with <code>KafkaProducer.partitionsFor()</code> in MAX_BLOCK_MS_DOC (JavaDoc markup does not work here...)

(There is also "block.on.buffer.full" in BUFFER_MEMORY_DOC which should actually be BLOCK_ON_BUFFER_FULL_CONFIG; however, this is deprecated and changing it gives the same error as above -- what does make sense it this case.)

What do you think about this? Should I include some of it in this PR?

[mjsax]

@ijuma @granthenke Just updated this.

[ewencp]

LGTM, thanks @mjsax!