Hi All
I have two questions regarding Observers in ZK.
(1) Is it possible to increase the number of observers in the cluster
dynamically?
(2) How many observers can I add given that I will seldom write into the
cluster but will have a lot of reads coming into the system? Can I run a
cluster
Sorry as an addendum I had one more question.
(1) If I snapshot the data on other observer machines will I be able to
bootstrap new observers with it? Given that writes are like a one time
thing.
Cheers
A
On Wed, Jul 21, 2010 at 10:30 AM, Avinash Lakshman
avinash.laksh...@gmail.com wrote
On Wed, Jul 21, 2010 at 10:30 AM, Avinash Lakshman
avinash.laksh...@gmail.com wrote:
(1) Is it possible to increase the number of observers in the cluster
dynamically?
Not quite, but practically speaking you can do as good as this.
In general, pretty much any ZK configuration change can
Hi Avinash -
(1) Is it possible to increase the number of observers in the cluster
dynamically?
Not really - you can use the same rolling-restart technique that is often
mentioned on this list for adding servers to the ensemble, but you can't add
them and expect that ZK will auto-find them
Any example scripts for the rolling restart technique that anyone would be
kind enough to share?
Thanks
Avinash
On Wed, Jul 21, 2010 at 10:44 AM, Henry Robinson he...@cloudera.com wrote:
Hi Avinash -
(1) Is it possible to increase the number of observers in the cluster
dynamically
will leave it to you to fix my silly errors. :-)
Note that you probably don't need to do this to the observers since they
don't need to know about other
observers.
On Wed, Jul 21, 2010 at 10:48 AM, Avinash Lakshman
avinash.laksh...@gmail.com wrote:
Any example scripts for the rolling restart
Thanks! Also thanks are due to the entire ZK committer team who helped
enormously in getting the patch into shape.
Since the JIRA is now a long and complicated read, I want to summarise a
couple of important points here (although the docs have most of this
information).
1. Observers must
.
Since the JIRA is now a long and complicated read, I want to summarise a
couple of important points here (although the docs have most of this
information).
1. Observers must currently be used with electionAlg=0; this is due to a
limitation of the other election algorithms which is being
be confused as to what's current and what's future.
(this comes from apache - me - you) I'd encourage all of you that are
interested in things like Observers to follow the dev list, it would be
great if you all could try out the Observers feature (and the other
features that we are working on for 3.3.0
