Home | About | Sematext search-lucene.com search-hadoop.com
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB
 Search Hadoop and all its subprojects:

Switch to Threaded View
Kafka >> mail # dev >> understanding partitions based on wiki example of profile visits


Copy link to this message
-
Re: understanding partitions based on wiki example of profile visits
Yes, your description is correct. A particular member's data would all be
in one partition.

Broker partitions are just the unit of parallelism--think of each partition
as a totally ordered log you can append to and read from. The consumption
of one of these partition logs is single threaded.

The guarantee is that all messages are added to a partition in the order
they arrive. From the point of view of a single producer client this will
also be the order in which they are sent. These messages are then delivered
in this order to a consumer thread.

Hope that helps.

-Jay
On Sun, Nov 25, 2012 at 7:54 PM, S Ahmed <[EMAIL PROTECTED]> wrote:

> The wiki states "Consider an application that would like to maintain an
> aggregation of the number of profile visitors for each member. It would
> like to send all profile visit events for a member to a particular
> partition and, hence, have all updates for a member to appear in the same
> stream for the same consumer thread." (
> http://incubator.apache.org/kafka/design.html)
>
> So say I have 5 broker servers, now my producer will send a message for a
> particular profile page visit, with the default algorithm using
> hash(member_id)%num_partitions
> to figur out which broker server to send it it.
>
> So a particular members pageview messages will all go to a single server
> then, is this the case?  And therefore all the messages for a given user
> will be in the correct order also right?
>
> So a consumer group that subscribes to the 'profile-page-view' topic will
> consume page view related messages, is it possible to subscribe to a
> particular broker partition also?
>
> Are broker partitions meant for cases when you want all messages to be
> saved on the same node?
>
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB