Then the wiki is incorrect. On Fri, Jun 11, 2010 at 11:33 AM, Aaron Blew <aaronb...@gmail.com> wrote: > That makes sense. It still seems to conflict with what's stated in the > wiki: > "...the remaining N-2 replicas, if any, are placed on the first nodes along > the ring in the *same* rack as the first" > -Aaron > > On Fri, Jun 11, 2010 at 11:20 AM, Jonathan Ellis <jbel...@gmail.com> wrote: >> >> You're mis-parsing the first. It says "place one replica in a >> different datacenter, and the others on different racks in the same >> one," where the antecedent of "one" is "datacenter," not rack. >> >> On Fri, Jun 11, 2010 at 11:09 AM, Blew, Aaron <aaron.b...@iovation.com> >> wrote: >> > The first text says the N-2 replicas are placed in the same rack while >> > the >> > second text indicates that the N-2 replicas will be placed in different >> > racks. >> > Am I missing something? >> > -Aaron >> > --- >> > Aaron Blew - >> > Sr. Infrastructure Engineer | The Automator >> > iovation - The Power of Reputation™ >> > aaron.b...@iovation.com >> > On Jun 11, 2010, at 10:48 AM, Jonathan Ellis wrote: >> > >> > I'm not sure what parts of these you think are in conflict. >> > >> > On Fri, Jun 11, 2010 at 10:34 AM, Blew, Aaron <aaron.b...@iovation.com> >> > wrote: >> > >> > Hello, >> > >> > I was browsing the docs for the RackAware replication strategy and saw >> > this >> > on the wiki: >> > >> > "RackAwareStrategy: replica 2 is placed in the first node along the ring >> > the >> > belongs in another data center than the first; the remaining N-2 >> > replicas, >> > if any, are placed on the first nodes along the ring in the *same* rack >> > as >> > the first" >> > >> > However the storage.conf comments say the following: >> > >> > "Strategy: Setting this to the class that implements >> > IReplicaPlacementStrategy will change the way the node picker works. >> > Out of >> > the box, Cassandra provides >> > org.apache.cassandra.locator.RackUnawareStrategy >> > and org.apache.cassandra.locator.RackAwareStrategy (place one replica in >> > a >> > different datacenter, and the others on different racks in the same >> > one.)" >> > >> > To me the comments in storage.conf make more sense since you'd want >> > datacenter diversity for the data as well as rack level diversity within >> > the >> > local datacenter. Which one is accurate? Is the disparity a result of >> > the >> > wiki page not being updated after the behavior changed with a release? >> > >> > Thanks all, >> > >> > -Aaron >> > >> > --- >> > >> > Aaron Blew - >> > >> > Sr. Infrastructure Engineer | The Automator >> > >> > iovation - The Power of Reputation™ >> > >> > aaron.b...@iovation.com >> > >> > >> > >> > iovation >> > >> > 111 SW Fifth Avenue >> > >> > Suite 3200 >> > >> > Portland, OR 97204 >> > >> > http://www.iovation.com/ >> > >> > The information contained in this email message may be privileged, >> > confidential and protected from disclosure. If you are not the intended >> > recipient, any dissemination, distribution or copying is strictly >> > prohibited. If you think that you have received this email message in >> > error, >> > please notify the sender by reply email and delete the message and any >> > attachments. >> > >> > >> > >> > >> > -- >> > Jonathan Ellis >> > Project Chair, Apache Cassandra >> > co-founder of Riptano, the source for professional Cassandra support >> > http://riptano.com >> > >> > >> >> >> >> -- >> Jonathan Ellis >> Project Chair, Apache Cassandra >> co-founder of Riptano, the source for professional Cassandra support >> http://riptano.com > >
-- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
