@brief Set statistics callback in provided conf object.
The statistics callback is triggered from rd_kafka_poll() every
\c statistics.interval.ms (needs to be configured separately).
Function arguments:
- \p rk - Kafka handle
- \p json - String containing the statistics data in JSON format
- \p json_len - Length of \p json string.
- \p opaque - Application-provided opaque.
If the application wishes to hold on to the \p json pointer and free
it at a later time it must return 1 from the \p stats_cb.
If the application returns 0 from the \p stats_cb then librdkafka
will immediately free the \p json pointer.
@brief Set statistics callback in provided conf object.
The statistics callback is triggered from rd_kafka_poll() every \c statistics.interval.ms (needs to be configured separately). Function arguments: - \p rk - Kafka handle - \p json - String containing the statistics data in JSON format - \p json_len - Length of \p json string. - \p opaque - Application-provided opaque.
If the application wishes to hold on to the \p json pointer and free it at a later time it must return 1 from the \p stats_cb. If the application returns 0 from the \p stats_cb then librdkafka will immediately free the \p json pointer.