You can always use more partitions to get more parallelism in the consumers.
Thanks, Jun On Thu, Aug 29, 2013 at 12:44 PM, Rajasekar Elango <rela...@salesforce.com>wrote: > So what is best way to load balance multiple consumers consuming from topic > filter. > > Let's say we have 4 topics with 8 partitions and 2 consumers. > > Option 1) To load balance consumers, we can set num.streams=4 so that both > consumers split 8 partitions. but can only use half of consumer streams. > > Option 2) Configure mutually exclusive topic filter regex such that 2 > topics will match consumer1 and 2 topics will match consumer2. Now we can > set num.streams=8 and fully utilize consumer streams. I believe this will > improve performance, but if consumer dies, we will not get any data from > the topic used by that consumer. > > What would be your recommendation? > > Thanks, > Raja. > > > On Thu, Aug 29, 2013 at 12:42 PM, Neha Narkhede <neha.narkh...@gmail.com > >wrote: > > > >> 2) When I started mirrormaker with num.streams=16, looks like 16 > > consumer > > threads were created, but only 8 are showing up as active as owner in > > consumer offset tracker and all topics/partitions are distributed > between 8 > > consumer threads. > > > > This is because currently the consumer rebalancing process of assigning > > partitions to consumer streams is at a per topic level. Unless you have > at > > least one topic with 16 partitions, the remaining 8 threads will not do > any > > work. This is not ideal and we want to look into a better rebalancing > > algorithm. Though it is a big change and we prefer doing it as part of > the > > consumer client rewrite. > > > > Thanks, > > Neha > > > > > > On Thu, Aug 29, 2013 at 8:03 AM, Rajasekar Elango < > rela...@salesforce.com > > >wrote: > > > > > So my understanding is num of active streams that a consumer can > utilize > > is > > > number of partitions in topic. This is fine if we consumer from > specific > > > topic. But if we consumer from TopicFilter, I thought consumer should > > able > > > to utilize (number of topics that match filter * number of partitions > in > > > topic) . But looks like number of streams that consumer can use is > > limited > > > by just number if partitions in topic although it's consuming from > > multiple > > > topic. > > > > > > Here what I observed with 1 mirrormaker consuming from whitelist '.+'. > > > > > > The white list matches 5 topics and each topic has 8 partitions. I used > > > consumer offset checker to look at owner of each/topic partition. > > > > > > 1) When I started mirrormaker with num.streams=8, all topics/partitions > > are > > > distributed between 8 consumer threads. > > > > > > 2) When I started mirrormaker with num.streams=16, looks like 16 > consumer > > > threads were created, but only 8 are showing up as active as owner in > > > consumer offset tracker and all topics/partitions are distributed > > between 8 > > > consumer threads. > > > > > > So this could be bottleneck for consumers as although we partitioned > > topic, > > > if we are consuming from topic filter it can't utilize much of > > parallelism > > > with num of streams. Am i missing something, is there a way to make > > > cosumers/mirrormakers to utilize more number of active streams? > > > > > > > > > -- > > > Thanks, > > > Raja. > > > > > > > > > -- > Thanks, > Raja. >
