I don’t have any figures but I can tell you that at some point as you scale, Cassandra will get cheaper overall than an RDBMS. We have plenty of clients who have happily migrated to Cassandra from RDBMS because they’ve hit (cost effective) scale limits on RDBMS x (most RDBMSs you can name).
For a write-heavy workload, the cross-over point where Cassandra become an overall cheaper options is likely to come earlier (because Cassandra is very efficient at writes). In addition to cost as you scale, you also need to consider requirements like always-on availability - relatively easy to achieve with Cassandra and next to impossible to achieve with RDBMS. Cheers Ben On Thu, 15 Jun 2017 at 18:17 Ali Akhtar <ali.rac...@gmail.com> wrote: > A client recently inquired about the costs of running Cassandra vs a > traditional RDBMS like Postgres or Mysql, in the cloud. > > They are releasing a b2b product similar to Slack, Trello, etc which will > have a free tier. And they're concerned about the costs of running it on > Cassandra, and whether it may be too expensive if it gets popular. > > They have a write heavy workload, where data is being received 24/7, > analyzed and the results written to Cassandra. A few times a day, users > will view the results of the analysis, which will be the read portion of > the system. > > Its my understanding that it may cost slightly, e.g 10-15% more to run > this system on Cassandra vs an RDBMS, because it needs more nodes, and > higher tier of AWS / GCE instances to run. > > Can anyone who has experience scaling Cassandra share their insights? > > Costs, metrics (e.g users, requests per second), etc would be really > helpful! > -- *Ben Slater* *Chief Product Officer <https://www.instaclustr.com/>* <https://www.facebook.com/instaclustr> <https://twitter.com/instaclustr> <https://www.linkedin.com/company/instaclustr> Read our latest technical blog posts here <https://www.instaclustr.com/blog/>. This email has been sent on behalf of Instaclustr Pty. Limited (Australia) and Instaclustr Inc (USA). This email and any attachments may contain confidential and legally privileged information. If you are not the intended recipient, do not copy or disclose its content, but please reply to this email immediately and highlight the error to the sender and then immediately delete the message.
