Hi Jun, If you read my previous posts, based on current re balancing logic, if we consumer from topic filter, consumer actively use all streams. Can you provide your recommendation of option 1 vs option 2 in my previous post?
Thanks, Raja. On Thu, Aug 29, 2013 at 11:42 PM, Jun Rao <[email protected]> wrote: > 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 > <[email protected]>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 <[email protected] > > >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 < > > [email protected] > > > >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. > > > -- Thanks, Raja.
