On 04/05/2012 03:19 PM, ruslan usifov wrote:
Hello
It's looks that cassandra 1.0.x is stable, and have interesting things
like offheap memtables and row cashes, so we want to upgrade to 1.0
version from 0.8. Is it possible to do without cluster downtime (while
we upgrade all nodes)? I mean follow: when we begin upgrade at some
point in working cluster will be mix of 0.8 (nodes that are not
upgraded yet) and 1.0(nodes that already upgraded) so i am concerned
about this situation, i.e. communications between nodes can be broken
because version communication protocol incompatibilies
This is from the NEWs file in the 1.0 upgrade:
1.0
===
Upgrading
---------
- Upgrading from version 0.7.1+ or 0.8.2+ can be done with a rolling
restart, one node at a time. (0.8.0 or 0.8.1 are NOT
network-compatible
with 1.0: upgrade to the most recent 0.8 release first.)
You do not need to bring down the whole cluster at once.
- After upgrading, run nodetool scrub against each node before running
repair, moving nodes, or adding new ones.