Specify data type for key when producing a message

[canique]

• PHP version: 7.4
• librdkafka version: 0.11.6
• php-rdkafka version:
• kafka version:

When producing a record like this:

$topic->produce(RD_KAFKA_PARTITION_UA, 0, json_encode($payload), intval($recordId));

I'd need the key ($recordId) to be an 8 byte long value.
I think it is treated as string? Is there a way to tell the library to produce a long?

[arnaud-lb]

Hi @canique

I'm not sure that Kafka can store different key types: I believe that keys are just byte arrays.

If you pass an int to ->produce(), it will be converted to its decimal representation as a string. You can convert that back with intval($key) when consuming messages.

If you prefer an 8 byte long value, you can use pack('J', $key). You can convert that back with unpack('J', $key) when consuming messages.