I am doing some on-the-job-learning on this newer feature of the 3.x line, where the token generation algorithm will compensate for different size nodes in a cluster. In fact, it is one of the main reasons I upgraded to 3.0.13, because I have a number of original nodes in a cluster that are about half the size of the newer nodes. With the same number of vnodes, they can get overwhelmed with too much data and have to be rebuilt, etc.
So, I am cutting vnodes in half on those original nodes and rebuilding them. So far, it is working as designed. The data size is about half on the smaller nodes. With the more current advice being to use less vnodes, for the original question below, I might consider adding the new node in at 256 vnodes and then rebuilding all the other nodes at 128. Of course the cluster size and amount of data would be important factors, as well as the future growth of the cluster and the expected size of any additional nodes. Sean Durity From: Jeff Jirsa [mailto:jji...@gmail.com] Sent: Thursday, August 17, 2017 4:20 PM To: cassandra <user@cassandra.apache.org> Subject: Re: Adding a new node with the double of disk space If you really double the hardware in every way, it's PROBABLY reasonable to double num_tokens. It won't be quite the same as doubling all-the-things, because you still have a single JVM, and you'll still have to deal with GC as you're now reading twice as much and generating twice as much garbage, but you can probably adjust the tuning of the heap to compensate. On Thu, Aug 17, 2017 at 1:00 PM, Kevin O'Connor <ke...@reddit.com.invalid<mailto:ke...@reddit.com.invalid>> wrote: Are you saying if a node had double the hardware capacity in every way it would be a bad idea to up num_tokens? I thought that was the whole idea of that setting though? On Thu, Aug 17, 2017 at 9:52 AM, Carlos Rolo <r...@pythian.com<mailto:r...@pythian.com>> wrote: No. If you would double all the hardware on that node vs the others would still be a bad idea. Keep the cluster uniform vnodes wise. Regards, Carlos Juzarte Rolo Cassandra Consultant / Datastax Certified Architect / Cassandra MVP Pythian - Love your data rolo@pythian | Twitter: @cjrolo | Skype: cjr2k3 | Linkedin: linkedin.com/in/carlosjuzarterolo <https://urldefense.proofpoint.com/v2/url?u=http-3A__linkedin.com_in_carlosjuzarterolo&d=DwMFaQ&c=MtgQEAMQGqekjTjiAhkudQ&r=aC_gxC6z_4f9GLlbWiKzHm1vucZTtVYWDDvyLkh8IaQ&m=rgNxV3xe5LAF1aAaZLAUezh4puIe3DKneEjHH-cf4tk&s=z8ZBxsxrkh0RG6ClNq3p1gk-3R8hVhVe7eoUOKurPgI&e=> Mobile: +351 918 918 100<tel:+351%20918%20918%20100> www.pythian.com<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.pythian.com_&d=DwMFaQ&c=MtgQEAMQGqekjTjiAhkudQ&r=aC_gxC6z_4f9GLlbWiKzHm1vucZTtVYWDDvyLkh8IaQ&m=rgNxV3xe5LAF1aAaZLAUezh4puIe3DKneEjHH-cf4tk&s=HD-QYimYZSKc1pzlsMXGp7te8RiXRqN1XLCuSZU1jos&e=> On Thu, Aug 17, 2017 at 5:47 PM, Cogumelos Maravilha <cogumelosmaravi...@sapo.pt<mailto:cogumelosmaravi...@sapo.pt>> wrote: Hi all, I need to add a new node to my cluster but this time the new node will have the double of disk space comparing to the other nodes. I'm using the default vnodes (num_tokens: 256). To fully use the disk space in the new node I just have to configure num_tokens: 512? Thanks in advance. --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org<mailto:user-unsubscr...@cassandra.apache.org> For additional commands, e-mail: user-h...@cassandra.apache.org<mailto:user-h...@cassandra.apache.org> -- ________________________________ The information in this Internet Email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this Email by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this Email are subject to the terms and conditions expressed in any applicable governing The Home Depot terms of business or client engagement letter. The Home Depot disclaims all responsibility and liability for the accuracy and content of this attachment and for any damages or losses arising from any inaccuracies, errors, viruses, e.g., worms, trojan horses, etc., or other items of a destructive nature, which may be contained in this attachment and shall not be liable for direct, indirect, consequential or special damages in connection with this e-mail message or its attachment.
