Thank you Joaquim for the advice. I seem to have sent this email with the wrong subject. It should have been Upgrading from Cassandra 2.1.12 to 3.7, but too late now.
The plan is to upgrade from 2.1.12 to 3.7 and to maintain a heterogeneous cluster only for a short time, while we observe how 3.7 reacts to our client applications with traffic, then proceed with upgrading all DCs to 3.7. In our current installation we are using memtable_allocation_type: offheap_objects. Support for offheap_objects was removed in the 3.0.x branch and only added back in 3.4+, so an upgrade to 3.0.9 will not be possible for me unless I change this parameter. Still looking to hear from others about upgrade experiences, problems etc. -Razi From: Joaquin Casares <joaq...@thelastpickle.com> Reply-To: "user@cassandra.apache.org" <user@cassandra.apache.org> Date: Friday, September 23, 2016 at 11:41 AM To: "user@cassandra.apache.org" <user@cassandra.apache.org> Cc: "Khaja, Raziuddin (NIH/NLM/NCBI) [C]" <raziuddin.kh...@nih.gov> Subject: Re: Upgrading from Cassandra 2.1.12 to 3.0.9 Hello Razi, Since you were using a highly stable version of 2.1.x, you may want to stick with using 3.0.9. 3.7 has introduced many great features, but has not been as heavily tested in production as 3.0.9. Running heterogenous clusters, even when using the same major version (e.g. 3.0.8 and 3.0.9), is never recommended. Running a cluster that spans major releases, for longer than the timespan of a routine upgrade, is strongly not advised. Hope that helps! Joaquin Casares Consultant Austin, TX Apache Cassandra Consulting http://www.thelastpickle.com On Fri, Sep 23, 2016 at 8:17 AM, Khaja, Raziuddin (NIH/NLM/NCBI) [C] <raziuddin.kh...@nih.gov<mailto:raziuddin.kh...@nih.gov>> wrote: Hello all, I would like to upgrade my Cassandra cluster from 2.1.12 to 3.7. I have read the following documentation: • http://docs.datastax.com/en/latest-upgrade/upgrade/cassandra/upgrdCassandra.html • https://github.com/apache/cassandra/blob/cassandra-3.7/NEWS.txt but still had some questions: • The upgrdCassandra.html page says : “Upgrade from Cassandra 2.1 versions later or equal to 2.1.9 directly to Cassandra 3.0.x”, and I am not sure if this includes 3.x, my question is: Can I upgrade directly to 3.7? • Can I run a heterogeneous cluster, with one DC running 2.1.12 and another DC running 3.7? Thanks, -Razi
