Thank you Paulo for your detailed answer!
I was not monitoring NEWS.txt in the Git repo so far but that file
definitely has info I was looking for.
cheers
Attila Wind
http://www.linkedin.com/in/attilaw <http://www.linkedin.com/in/attilaw>
Mobile: +49 176 43556932
09.10.2021 15:07 keltezéssel, Paulo Motta írta:
Hi Attila,
Minor version upgrades are generally fine to do in-place, unless
otherwise specified on NEWS.txt
<https://github.com/apache/cassandra/blob/cassandra-4.0.1/NEWS.txt
<https://github.com/apache/cassandra/blob/cassandra-4.0.1/NEWS.txt>>
for the specific versions you're upgrading. Cassandra is designed with
this goal in mind, and potentially disruptive changes can only be
introduced in major versions, which require a little more care during
the upgrade process.
It's definitely safe to do an in-place one-node-at-a-time upgrade for
minor versions in the same major series (ie. 4.0-alpha to 4.0.1).
Nevertheless it doesn't hurt to take a global snapshot "just-in-case",
so you can rollback in case you run into an unexpected issue, but this
is just extra safety and not strictly required.
Unfortunately there's no official upgrade guide yet, this is something
the community is working on to provide soon, but you can find some
unofficial ones with a quick google search.
Major upgrades are also designed to be harmless, but a little bit more
preparation is required to ensure a smooth ride due to potentially
non-compatible changes. I've written an upgrade guide sometime ago
which can be useful to prepare for a major upgrade, but can also apply
to minor upgrades as well to ensure extra safety during the process:
http://monkeys.chaordic.com.br/operation/2014/04/11/zero-downtime-cassandra-upgrade.html
<http://monkeys.chaordic.com.br/operation/2014/04/11/zero-downtime-cassandra-upgrade.html>
Cheers and good luck!
Paulo
Em sáb., 9 de out. de 2021 às 06:56, Attila Wind
<attilaw@swf.technology> escreveu:
Hi all,
I have 2 quick questions
1. We have a cluster running 4.0-alpha4. Now 4.0.1 is out and
obviously it would make lots of sense to switch to this version.
Does anyone know if we can do it simply "in place"? I mean we just
ugrade the software and restart? Or it would not work / would be
dangerous due to some storage layer incompatibilities or other
risk factors? So better to run a (usual) data migration process..?
2. Actually the above brought the more generic question: is the
community maintaining any kind of guide/readme/whatever one can
use to find answer for similar questions? As a user I see the
changelog and that's cool but that is not providing obvious
answers (of course). So I mean some sort of migration hints/guide.
thanks!
--
Attila Wind
http://www.linkedin.com/in/attilaw
<http://www.linkedin.com/in/attilaw>
Mobile: +49 176 43556932
