Thanks Mahadev, your information is really helpful :-) On Wed, Jul 1, 2009 at 12:14 AM, Mahadev Konar <maha...@yahoo-inc.com>wrote:
> Hi Qian, > Sorry for the delayed response. ZooKeeper guarantees that their is > backwards compatibility with minor releases. So, 3.2* is backwards > compatible with 3.1*. So, what Ted mentions below related to rolling > upgrade > should work. > > Hope this helps. > Thanks > Mahadev > > > Ted Dunning: > > A rolling update works very well for that. You can also change the number > of nodes in the cluster. > > To do this, you replace the config files on the surviving servers and on > the > new server. > > Then take down the one that is leaving the cluster and then one by one > restart the servers that will remain in the cluster. Then start the new > server. > > If you only have 3 ZK servers, you might want to do the upgrade in two > steps > if you are totally paranoid about running with just 2 servers in your > cluster. In that scenario, you would add the new server to the config and > restart each of the 3 ZK servers and staring the new one. That gives you a > ZK cluster with 4 servers. Another rolling update can reconfigure it to > have only the 3 servers you want. > > Make sure you leave several seconds between restarting each server. That > will give the cluster time to calm down and do any necessary leader > elections > > > On 6/28/09 11:03 PM, "Qian Ye" <yeqian....@gmail.com> wrote: > > > A related question. If I have run a Zookeeper service with many > ephemeral > > znodes on five servers, then I want to replace one of the servers by a > new > > one, and the new server has a new IP. How can I do the job without any > loss > > of data ? > > > > Thanks > > > > > > On Mon, Jun 29, 2009 at 9:24 AM, Qian Ye <yeqian....@gmail.com> wrote: > > > >> Thanks for the explanation, it sounds great. > >> > >> It seems that I should study more on Zookeeper :-) > >> > >> regards > >> > >> > >> On Mon, Jun 29, 2009 at 2:15 AM, Ted Dunning <ted.dunn...@gmail.com > >wrote: > >> > >>> I don't think you should be very nervous at all. > >>> > >>> There are two questions: > >>> > >>> 1) can 3.1.1 go to 3.2 with no down time. This is very likely, but a > >>> wiser > >>> head than mine should have final say > >>> > >>> 2) can 3.1.1 go to 3.2 with < 1 minute of downtime. The is for sure. > >>> > >>> Neither option involves data loss. > >>> > >>> ZK is actually really really good for HA operations. > >>> > >>> On Sun, Jun 28, 2009 at 4:55 AM, Qian Ye <yeqian....@gmail.com> wrote: > >>> > >>>> your answer makes me nervous about upgrade Zookeeper > >>>> server > >>>> > >>> > >> > >> > >> > >> -- > >> With Regards! > >> > >> Ye, Qian > >> Made in Zhejiang University > >> > >> > > > > -- With Regards! Ye, Qian Made in Zhejiang University
