Gratzi Eric for the correction on Zookeeper...
On Tue, Oct 18, 2016 at 1:48 PM, Erick Erickson <erickerick...@gmail.com>
> bq: ...whether it's OK to just copy the data files between 4.3 and 6.x
> NOT ok. Solr (well, Lucene really) guarantees to read _one_ major version
> behind. So a Solr 5x will read a solr 4x. But a Solr 6x is not guaranteed
> at all to read a 4x. And in fact removing back-compat complexification is
> one of the benefits of moving to a new major version.
> You can use the 5x IndexUpgraderTool to migrate from 4x->5x, then run
> 6x over the upgraded index.
> All that said, I completely agree with John's advice to re-index entirely
> from scratch if at all possible.
> It's perfectly possible to run with a single Zookeeper. The quorum
> formula is N/2 + 1. If you only have 1 ZK node, then 1 represents
> quorum. It's just not advisable. Zk is responsible for presenting the
> cluster topology to the entire set of Solr instances, you want it
> to be robust so 3 is the recommended minimum. BTW, It's quite rare
> to need more than that unless you're at pretty massive scale (hundreds
> of Solr instances and/or collections), and even in these cases it's
> usually best to use Observers....
> On Tue, Oct 18, 2016 at 2:28 PM, John Bickerstaff
> <j...@johnbickerstaff.com> wrote:
> > For what it's worth, (and it may not work for your situation) I decided
> > to upgrade, but to "upgrade by replacing". In other words, I just
> > installed 6.x and because I had set up my configs for "include" I didn't
> > have to worry about what would be different about the "new"
> > and the managed_schema file. Instead, I was able to use a copy from one
> > the sample projects and add my "included" configs.
> > Then, after creating the same collection structure in 6.x that I had in
> > 5.x instances, I just re-indexed everything into the new 6.x Solr.
> > The big deal (probably) is whether it will cost you days to re-index and
> > whether you have the resources to do that.
> > I don't know if the index remained the same because I didn't have to
> > trouble myself with that due to the replacement. I'm sure others on the
> > list can tell us whether it's OK to just copy the data files between 4.3
> > and 6.x (I'd guess not...)
> > By the way - unless I misunderstand the Zookeeper docs, you can't get
> > with any less than 3 Zookeeper nodes. So keep that in mind.
> > I have my rough notes about what I did available online. You can go here
> > for the link...
> > https://www.linkedin.com/pulse/actual-solrcloud-vms-
> > On Tue, Oct 18, 2016 at 11:28 AM, sputul <sputu...@gmail.com> wrote:
> >> We are using Solr 4.3, sing Zoopeeker on development manage Solr Cloud
> >> having
> >> one or two nodes. Will it be easier to migrate to Solr 5 first or
> should I
> >> migrate to Solr 6 directly? I see Core definition has changed. Anything
> >> else
> >> worth noting?
> >> The goal is to also use HTTPS perhaps after everything works in my local
> >> environment using Single Zookeeper and a one or more Solr Nodes. Thanks.
> >> --
> >> View this message in context: http://lucene.472066.n3.
> >> nabble.com/Migration-from-Solr-4-tp4301788.html
> >> Sent from the Solr - User mailing list archive at Nabble.com.