I'm looking at the document entitled "A Guide to the Kafka Protocol"
located here:
https://cwiki.apache.org/KAFKA/a-guide-to-the-kafka-protocol.html
It shows a produce request as containing a number of message sets, which are
grouped first by topic and second by partition (a 32-bit integer).
However, each
message in a message set contains a Key field, which is described as follows:
The key is an optional message key that was used for partition assignment.
The key can be null.
I notice the use of "was" (past tense) above. That seems to suggest that the
Key field was once used to specify a partition (at the granularity of each
individual message), but the plan for the future is to instead use the 32-bit
partition value preceding each message set. Is this correct? If so, when I am
creating a produce request for 0.8, what should I use for the 32-bit partition
value, and how does this relate to the Key field of each individual message?
Ideally, I would like to just send a produce request and let the broker choose
the partition. How do I accomplish this in 0.8, and are there plans to change
this after 0.8?
Thanks,
Dave
On Tue, May 21, 2013 at 10:47 AM, Neha Narkhede <neha.narkh...@gmail.com> wrote:
> No. In 0.8, if you don't specify a key for a message, it is sent to any of
> the available partitions. In other words, the partition id is selected on
> the partition and the server doesn't get -1 as the partition id.
>
> Thanks,
> Neha
>
>
> On Tue, May 21, 2013 at 9:54 AM, Dave Peterson <dspeter...@tagged.com>wrote:
>
>> In the version 0.8 wire format for a produce request, does a value of -1
>> still indicate "use a random partition" as it did for 0.7?
>>
>> Thanks,
>> Dave
>>
