RE: Cassandra going OOM due to tombstones (heapdump screenshots provided)

2020-01-30 Thread Steinmaurer, Thomas
If possible, prefer m5 over m4, cause they are running on a newer hypervisor (KVM-based), single core performance is ~ 10% better compared to m4 with m5 even being slightly cheaper than m4. Thomas From: Erick Ramirez Sent: Donnerstag, 30. Jänner 2020 03:00 To: user@cassandra.apache.org

Re: Cassandra OS Patching.

2020-01-30 Thread Erick Ramirez
There is no need to shutdown the application because you should be able to carry out the operating system upgraded without an outage to the database particularly since you have a lot of nodes in your cluster. Provided your cluster has sufficient capacity, you might even have the ability to

Re: [EXTERNAL] How to reduce vnodes without downtime

2020-01-30 Thread Anthony Grasso
Hi Maxim, Basically what Sean suggested is the way to do this without downtime. To clarify the, the *three* steps following the "Decommission each node in the DC you are working on" step should be applied to *only* the decommissioned nodes. So where it say "*all nodes*" or "*every node*" it

Re: Cassandra OS Patching.

2020-01-30 Thread Michael Shuler
That is some good info. To add just a little more, knowing what the pending security updates are for your nodes helps in knowing what to do after. Read the security update notes from your vendor. Java or Cassandra update? Of course the service needs restarted - rolling upgrade and restart the

Re: Introducing DSBench

2020-01-30 Thread Jonathan Shook
Here is a link to get started with DSBench: https://github.com/datastax/dsbench-labs#getting-started and DataStax Labs: https://downloads.datastax.com/#labs On Thu, Jan 30, 2020 at 11:47 AM Jonathan Shook wrote: > > Some of you may remember NGCC talks on metagener (now VirtualDataSet) > and

Introducing DSBench

2020-01-30 Thread Jonathan Shook
Some of you may remember NGCC talks on metagener (now VirtualDataSet) and engineblock from 2015 and 2016. The main themes went something along the lines of "testing c* with realistic workloads is hard, sizing cassandra is hard, we need tools in this space that go beyond what cassandra-stress can

RE: [EXTERNAL] How to reduce vnodes without downtime

2020-01-30 Thread Durity, Sean R
Your procedure won’t work very well. On the first node, if you switched to 4, you would end up with only a tiny fraction of the data (because the other nodes would still be at 256). I updated a large cluster (over 150 nodes – 2 DCs) to smaller number of vnodes. The basic outline was this: *

How to reduce vnodes without downtime

2020-01-30 Thread Maxim Parkachov
Hi everyone, with discussion about reducing default vnodes in version 4.0 I would like to ask, what would be optimal procedure to perform reduction of vnodes in existing 3.11.x cluster which was set up with default value 256. Cluster has 2 DC with 5 nodes each and RF=3. There is one more

Re: KeyCache Harmless Error on Startup

2020-01-30 Thread Shalom Sagges
Thanks Erick! I will check with the owners of this keyspace, hoping to find the culprit. If they won't come up with anything, is there a way to read the key cache file? (as I understand it's a binary file) On another note, there's actually another keyspace I missed to point out on which I found a