On 4/6/2020 11:13 AM, Kudrettin Güleryüz wrote:
Can I run let's say, Solr 8.5.0 together with Solr 7.3.1. nodes while
replacing older nodes with 8.5.0 one by one?
We have a cloud with rather large disk space utilization. What is the
suggested way to handle this kind of situation? Building indexes takes
around 3 days to complete.
I'm assuming you're running in SolrCloud mode, which is what you get
when you combine Solr with ZooKeeper. If that is not the case, then
what I am saying below will not apply.
Running different major versions in the same cluster would not be
recommended. I cannot say whether the later version will write ZK
information in a way that the older version cannot deal with ... but
that is always possible.
A rolling upgrade might work perfectly, but it's not a chance I would be
willing to take when upgrading to a new major version. Upgrading to a
new minor version within the same major version would be safer, but also
not guaranteed.
What I would recommend is that you build a separate cluster with the
newer version and build new collections in that cluster. You can run
them in parallel as long as necessary. If you like, the new cluster can
use the same ZK ensemble as the old one, by using a different chroot on
the ZKHOST string. You're likely to need more hardware for this
approach than you would for a rolling upgrade.
Thanks,
Shawn
