Adding consumer batch-size matric to sarama

[varun06]

Problem Description

If I have to expose a consumer batch metric from sarama, is this -> https://github.com/Shopify/sarama/blob/master/consumer.go#L519-L545 right place to do it? parseRecords get batch as an argument, can I put len(batch) as consumer-batch-size in metric?

@dim @eapache

[dim]

@varun06 sorry this isn't my code, but I assume it depends on the Consumer.Fetch settings in https://github.com/Shopify/sarama/blob/master/config.go#L244

[varun06]

Thanks. I shall keep looking.