Main interface for consumer
Usage: Once ConsumerFetcherManager is created, startConnections() and stopAllConnections() can be called repeatedly until shutdown() is called.
An iterator that blocks until a value can be read from the supplied queue.
Tracks metrics for each topic the given consumer client has consumed data from.
Tracks metrics of the requests made by a given consumer client to all brokers, and the responses obtained from the brokers.
Range partitioning works on a per-topic basis.
The round-robin partition assignor lays out all the available partitions and all the available consumer threads.
A consumer of kafka messages
Stores the topic stats information of each consumer client in a (clientId -> ConsumerTopicStats) map.
Stores the fetch request and response stats information of each consumer client in a (clientId -> FetchRequestAndResponseStats) map.