Kafka is designed to have of the order of few thousands of partitions roughly less than 10,000. And the main bottleneck is zookeeper. A better way to design such a system is to have fewer partitions and use keyed messages to distribute the data over a fixed set of partitions.
Thanks, Neha On Oct 5, 2013 8:19 PM, "Ravindranath Akila" <ravindranathak...@gmail.com> wrote: > Initially, I thought dynamic topic creation can be used to maintain per > user data on Kafka. The I read that partitions can and should be used for > this instead. > > If a partition is to be used to map a user, can there be a million, or even > billion partitions in a cluster? How does one go about designing such a > model. > > Can the replication tool be used to assign, say partitions 1 - 10,000 on > replica 1, and 10,001 - 20,000 on replica 2? > > If not, since there is a ulimit on the file system, should one model it > based on a replica/topic/partition approach. Say users 1-10,000 go on topic > 10k-1, and has 10,000 partitions, and users 10,0001-20,000 go on topic > 10k-2, and has 10,000 partitions. > > Simply put, how can a million stateful data points be handled? (I deduced > that a userid-partition number mapping can be done via a partitioner, but > unless a server can be configured to handle only a given set of partitions, > with a range based notation, it is almost impossible to handle a large > dataset. Is it that Kafka can only handle a limited set of stateful data > right now?) > > > http://stackoverflow.com/questions/17205561/data-modeling-with-kafka-topics-and-partitions > > Btw, why does Kafka have to keep open each partition? Can't a partition be > opened for read/write when needed only? > > Thanks in advance! >
