It seems to me option 1) is easer. Option 2) has the same issue as option 1) since you have to manage different while lists.
A more general solution is probably to change the consumer distribution model to divide partitions across topics. That way, one can create as many streams as total # partitions for all topics. We can look into that in the future. Thanks, Jun On Fri, Aug 30, 2013 at 8:24 AM, Rajasekar Elango <rela...@salesforce.com>wrote: > Yeah. The actual bottleneck is actually number of topics that match the > topic filter. Num of streams is going be shared between all topics it's > consuming from. I thought about following ideas to work around this. (I am > basically referring to mirrormaker consumer in examples). > > Option 1). Instead of running one mirrormaker process with topic filter > ".+", We can start multiple mirrormaker process with topic filter matching > each topic (Eg: mirrormaker1 => whitelist topic1.* , mirrormaker2 > => whitelist topic2.* etc) > > But this adds some operations overhead to start and manage multiple > processes on the host. > > Option 2) Modify mirrormaker code to support list of whitelist filters and > it should create message streams for each filter > (call createMessageStreamsByFilter for each filter). > > What would be your recommendation..? If adding feature to mirrormaker is > worth kafka, we can do option 2. > > Thanks, > Raja. > > > > > On Fri, Aug 30, 2013 at 10:34 AM, Jun Rao <jun...@gmail.com> wrote: > > > Right, but if you set #partitions in each topic to 16, you can use a > total > > of 16 streams. > > > > Thanks, > > > > Jun > > > > > > On Thu, Aug 29, 2013 at 9:08 PM, Rajasekar Elango < > rela...@salesforce.com > > >wrote: > > > > > With option 1) I can't really use 8 streams in each consumer, If I do > > only > > > one consumer seem to be doing all work. So I had to actually use total > 8 > > > streams with 4 for each consumer. > > > > > > > > > > > > On Fri, Aug 30, 2013 at 12:01 AM, Jun Rao <jun...@gmail.com> wrote: > > > > > > > The drawback of 2), as you said is no auto failover. I was suggesting > > > that > > > > you use 16 partitions. Then you can use option 1) with 8 streams in > > each > > > > consumer. > > > > > > > > Thanks, > > > > > > > > Jun > > > > > > > > > > > > On Thu, Aug 29, 2013 at 8:51 PM, Rajasekar Elango < > > > rela...@salesforce.com > > > > >wrote: > > > > > > > > > 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 <jun...@gmail.com> > 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 > > > > > > <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. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > Thanks, > > > > > Raja. > > > > > > > > > > > > > > > > > > > > > -- > > > Thanks, > > > Raja. > > > > > > > > > -- > Thanks, > Raja. >
