I think might be cool, would be to have a feature where by you can tell a broker to stop accepting new data produced to it, but still allow consumers to consume from it.
That way, you can roll out new brokers to a cluster, turn off producing to the old nodes, then wait for the log retention period, and then remove the old nodes from the cluster. Does that make sense? Could it be easily done? Or is all this a non-issue anyway in 0.8? Maybe I should just wait for 0.8 to be ready, before doing my migration anyway..... Jason On Wed, Mar 20, 2013 at 6:42 AM, Neha Narkhede <neha.narkh...@gmail.com>wrote: > The zookeeper connection URL with namespace can be > zkhost1:123,zkhost2:123/newnamespace > > The wiki is up to date for Kafka 0.7.2. There is no officially supported > feature to do that sort of migration, I suggested one approach that I could > think of :-) > > Thanks, > Neha > > On Tuesday, March 19, 2013, Jason Rosenberg wrote: > > > I can do most of that I presume. > > > > It looks like to set up a separate namespace for zk, I can add /path at > the > > end of each node:port in my zkconnect string, e.g.: > > zkhost1:123/newnamespace,zkhost2:123/newnamespace > > right? > > > > For mirroring, there's some vague documentation here: > > https://cwiki.apache.org/KAFKA/kafka-mirroring-mirrormaker.html > > Is this the most up to date approach for 0.7.2? Set up a MirrorMaker > > intermediate process that consumes from the old and produces to the new? > > > > I am not able to restart producers one by one (as there are many, on a > > rather asynchronous update/restart cycle). But I can eventually get them > > migrated over, etc. > > > > Jason > > > > On Tue, Mar 19, 2013 at 7:07 PM, Neha Narkhede <neha.narkh...@gmail.com > <javascript:;> > > >wrote: > > > > > Can you do the following - > > > > > > 1. Start a mirror Kafka cluster with the new version on a separate > > > zookeeper namespace. Configure this to mirror data from the existing > > kafka > > > cluster. > > > 2. Move your consumers to pull data from the mirror > > > 3. For each producer, one at a time, change the zookeeper namespace to > > > point to the mirror and restart the producer. > > > 4. Once the producers have moved to mirror cluster, shutdown mirroring > > and > > > old cluster. > > > > > > Thanks, > > > Neha > > > > > > On Tuesday, March 19, 2013, Jason Rosenberg wrote: > > > > > > > I need to upgrade some kafka broker servers. So I need to seamlessly > > > > migrate traffic from the old brokers to the new ones, without losing > > > data, > > > > and without stopping producers. I can temporarily stop consumers, > etc. > > > > > > > > Is there a strategy for this? > > > > > > > > Also, because of the way we are embedding kafka in our framework, our > > > > brokerId's are auto-generated (based on hostname, etc.), so I can't > > > simply > > > > copy over broker log files, etc., by transferring an old brokerId to > a > > > new > > > > host. > > > > > > > > Is there a way to change the view of the cluster from the producer's > > > > standpoint, without doing so from the consumers standpoint? That > way, > > > the > > > > producers can start writing to the new brokers, while the consumers > > drain > > > > all data from the old brokers before switching to the new brokers. > > > > > > > > I don't actually care about ordering of messages, since the consumers > > are > > > > publishing them to a store that will index them properly based on > > source > > > > timestamp, etc. > > > > > > > > We are using zk for both producers and consumers connections. > > > > > > > > This is using 0.7.2. I assume in 0.8 it will be easier, since with > > > > replication, you can phase in the new servers gradually, etc., no? > > > > > > > > Thanks, > > > > > > > > Jason > > > > > > > > > >
