Different Solr versions in Solrcloud

2014-06-03 Thread Martin de Vries

Hi,

I have two questions about upgrading Solr:

- We upgrade Solr often, to match the latest version. We have a number 
of servers in a Solrcloud and prefer to upgrade one or two servers first 
and upgrade the other server a few weeks later when we are sure 
everything is stable. Is this the recommended way? Can Solr run 
different versions next to each other in a cloud?


- Do we need to adjust the luceneMatchVersion with every upgrade and do 
we need a reindex after every upgrade? (it takes a lot of time to 
reindex all cores)



Kind regards,

Martin


Re: Different Solr versions in Solrcloud

2014-06-03 Thread Shawn Heisey
On 6/3/2014 6:18 AM, Martin de Vries wrote:
 I have two questions about upgrading Solr:
 
 - We upgrade Solr often, to match the latest version. We have a number
 of servers in a Solrcloud and prefer to upgrade one or two servers first
 and upgrade the other server a few weeks later when we are sure
 everything is stable. Is this the recommended way? Can Solr run
 different versions next to each other in a cloud?

Solr is usually able to have slightly different versions working
together, but I don't know that I would recommend running for a few
weeks in that configuration.  In the context of SolrCloud, sometimes
changes to the data structures in zookeeper are required, which likely
will not work with a previous release.  If you do find that they will
work together, you can continue to do what you've been doing ... but you
do need to be on the lookout for clusterstate format changes and
possible interoperability bugs in the previous release.

 - Do we need to adjust the luceneMatchVersion with every upgrade and do
 we need a reindex after every upgrade? (it takes a lot of time to
 reindex all cores)

This is always recommended, but you can leave luceneMatchVersion alone
and run with your existing index until such time as you are ready to
re-index.  Note that as soon as you index anything at all (or optimize
your index), at least part of your index may be in a new index format,
so going back to the previous version with the existing index may not be
possible.

Thanks,
Shawn