Re: Resources to understand rebalancing

2023-10-26 Thread Vikas Kumar
Thanks for sharing this clear explanation, Jeff. Cheers! On Wed, Oct 25, 2023 at 5:58 PM Jeff Jirsa wrote: > Data ownership is defined by the token ring concept. > > Hosts in the cluster may have tokens - let's oversimplify to 5 hosts, each > with 1 token A=0, B=1000, C=2000, D=3000, E=4000 > >

Re: Backup and Restore Strategy and Tools

2023-10-26 Thread Miklosovic, Stefan via user
Hi Bhavesh, have you gone through Cassandra tools here (1)? Just search for "backup", there are couple (CLI) solutions out there for your problem. Feel tree to ping me on Cassandra Slack or privately if you want. Cheers https://cassandra.apache.org/_/ecosystem.html

Backup and Restore Strategy and Tools

2023-10-26 Thread Bhavesh Prajapati via user
Hi, I have 48 nodes, single DC, Apache Cassandra cluster running in Prod – version is 4.0.6. Currently, we are using a home-grown backup script based on nodetool snapshot that uploads backup to s3. We are using a home-grown restore script to recover incase of disaster. I am looking for a

Re: Upgrade from C* 3 to C* 4 per datacenter

2023-10-26 Thread Aaron Ploetz
Just a heads-up, but there have been issues (at least one) reported when upgrading a multi-DC cluster from 3.x to 4.x when the cluster uses node-to-node SSL/TLS encryption. This is largely attributed to the fact that the secure port in 4.x changes to 9142, whereas in 3.x it continues to run on

Re: Upgrade from C* 3 to C* 4 per datacenter

2023-10-26 Thread Sebastian Marsching
Hi, as we are currently facing the same challenge (upgrading an existing cluster from C* 3 to C* 4), I wanted to share our strategy with you. It largely is what Scott already suggested, but I have some extra details, so I thought it might still be useful. We duplicated our cluster using the

RE: Upgrade from C* 3 to C* 4 per datacenter

2023-10-26 Thread Michalis Kotsiouros (EXT) via user
Hello Jeff et al, Thanks a lot for your valuable info. Your comment covers all my queries. BR MK From: Jeff Jirsa Sent: October 26, 2023 15:48 To: user@cassandra.apache.org Cc: Michalis Kotsiouros (EXT) Subject: Re: Upgrade from C* 3 to C* 4 per datacenter On Oct 26, 2023, at 12:32 AM,

Re: Upgrade from C* 3 to C* 4 per datacenter

2023-10-26 Thread Jeff Jirsa
> On Oct 26, 2023, at 12:32 AM, Michalis Kotsiouros (EXT) via user > wrote: > >  > Hello Cassandra community, > We are trying to upgrade our systems from Cassandra 3 to Cassandra 4. We plan > to do this per data center. > During the upgrade, a cluster with mixed SW levels is expected. At

RE: Upgrade from C* 3 to C* 4 per datacenter

2023-10-26 Thread Michalis Kotsiouros (EXT) via user
Hello Scott, Thanks a lot for the immediate answer. We use a semi automated procedure to do the upgrade of the SW in our systems which is done per datacenter. Our limitation is that if we want to rollback we need to rollback the Cassandra nodes from the whole datacenter. May I return to the

Re: Upgrade from C* 3 to C* 4 per datacenter

2023-10-26 Thread C. Scott Andreas
The recommended approach to upgrading is to perform a replica-safe rolling restart of instances in each datacenter, one datacenter at a time. > In case of an upgrade failure, would it be possible to remove the data center from the cluster, restore the datacenter to C*3 SW and add it back to

Upgrade from C* 3 to C* 4 per datacenter

2023-10-26 Thread Michalis Kotsiouros (EXT) via user
Hello Cassandra community, We are trying to upgrade our systems from Cassandra 3 to Cassandra 4. We plan to do this per data center. During the upgrade, a cluster with mixed SW levels is expected. At this point is it possible to perform topology changes? In case of an upgrade failure, would it