Thanks .. So whats ideal number when we should stop ..say 100 ? On Friday, May 4, 2018, Jeff Jirsa <jji...@gmail.com> wrote:
> Cluster. The overhead is per cluster. > > There are two places you'll run into scaling pain here. > > 1) Size of the schema (which we have to serialize to send around) - too > many tables, or too many columns in tables, can cause serializing schema to > get really expensive and cause problems > 2) Too many memtables - assume that all of them will have some tiny > trivial amount of data in them, maybe 1MB. 200 * 1MB = 200MB of heap just > for empty memtables. If you have a thousand tables, that's a gigabyte of > heap, just for EMPTY memtables. > > > > > > On Fri, May 4, 2018 at 11:17 AM, Abdul Patel <abd786...@gmail.com> wrote: > >> I have 3 projects in pipeline adding 3 different cluster across all >> environwments would too costly option :) >> >> So 200 tables per keyspace or per cluster? >> >> >> On Friday, May 4, 2018, Durity, Sean R <sean_r_dur...@homedepot.com> >> wrote: >> >>> The issue is more with the number of tables, not the number of >>> keyspaces. Because each table has a memTable, there is a practical limit to >>> the number of memtables that a node can hold in its memory. (And scaling >>> out doesn’t help, because every node still has a memTable for every table.) >>> The practical table limit I have heard is in the low hundreds – maybe 200 >>> as a rough estimate. >>> >>> >>> >>> In general, we create a new cluster (instead of a new keyspace) for each >>> application. >>> >>> >>> >>> >>> >>> Sean Durity >>> >>> *From:* Abdul Patel <abd786...@gmail.com> >>> *Sent:* Thursday, May 03, 2018 5:56 PM >>> *To:* User@cassandra.apache.org >>> *Subject:* [EXTERNAL] Cassandra limitations >>> >>> >>> >>> Hi , >>> >>> >>> >>> In my environment, we are coming up with 3 to 4 new projects , hence new >>> keyspaces will be coming into picture. >>> >>> Do we have any limitations or performance issues when we hit to a number >>> of keyspaces or number of nodes vs keyspaces? >>> >>> Also connections limitations if any? >>> >>> >>> >>> I know as data grows we can add more nodes and memory but nor sure about >>> somethinh else which need to take into consideration. >>> >>> >>> >>> >>> >>> ------------------------------ >>> >>> 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. >>> >> >
