From user-return-61049-archive-asf-public=cust-asf.ponee.io@cassandra.apache.org Thu May 10 18:31:05 2018 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id E103D18063A for ; Thu, 10 May 2018 18:31:04 +0200 (CEST) Received: (qmail 40171 invoked by uid 500); 10 May 2018 16:31:02 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 40161 invoked by uid 99); 10 May 2018 16:31:02 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd2-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 10 May 2018 16:31:02 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd2-us-west.apache.org (ASF Mail Server at spamd2-us-west.apache.org) with ESMTP id 7E8A11A16F6 for ; Thu, 10 May 2018 16:31:02 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd2-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 1.898 X-Spam-Level: * X-Spam-Status: No, score=1.898 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=2, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001] autolearn=disabled Authentication-Results: spamd2-us-west.apache.org (amavisd-new); dkim=pass (1024-bit key) header.d=wikimedia.org Received: from mx1-lw-us.apache.org ([10.40.0.8]) by localhost (spamd2-us-west.apache.org [10.40.0.9]) (amavisd-new, port 10024) with ESMTP id 79auH8ctXXI6 for ; Thu, 10 May 2018 16:31:00 +0000 (UTC) Received: from mail-pf0-f180.google.com (mail-pf0-f180.google.com [209.85.192.180]) by mx1-lw-us.apache.org (ASF Mail Server at mx1-lw-us.apache.org) with ESMTPS id 724465FBEA for ; Thu, 10 May 2018 16:31:00 +0000 (UTC) Received: by mail-pf0-f180.google.com with SMTP id c10-v6so1320292pfi.12 for ; Thu, 10 May 2018 09:31:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wikimedia.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=yYsZ/SMUZctxmUkEi9CUuhGVMy2LIrU1wMcD51ocU5o=; b=MbSQRvPN4alHZHJfSmx56p4qPS0/kHqj/o+UELpsB8HMxFPH/Xq21yw9qiS9HCpGRX 2vqpmeHjMovnyG6BlZ7F/4wd8Zg7XasVH35AnbC/QaBMLYcHNKGO0BesKkDjEYpE2UHf gAy00nzScD0XYn7nYPLrSyfeh14ehgOP8BHhw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=yYsZ/SMUZctxmUkEi9CUuhGVMy2LIrU1wMcD51ocU5o=; b=ADMkCf/JYOIQANviFWz19my7Yeguc5y9g/x3ejT7WJ92z5SAP86igxTDn8b4GTqTaQ xbR+fPugW25MYlAJpCaJg8JLzC7KA7D1VdpNrU0pd/vtlElK8fDQrXtJSty3byfTSNsN 6Bmgbq5QCx7NvhvKwYzjaleSgzYrppO/B5ee6Gx2Txecbb0/Vnu63D9O1qkbcFo7rAWr S00ErlKN8MSEk+fvVws7qAnQ4L9zgWruPYL6/8IGJObfNNYc4V0dfJTXj+kBXxQtsZxW QsVC2YuxNOxoDx8aZJLmjxOVO0Erp0BSOyqi1v0arrfyhzHFwCGU2dwhWMPdfyhXIRxw 63Zw== X-Gm-Message-State: ALKqPwdkJa37DJc6HHobnz1PmuLbPTTRkq2oZLIoAVp3BHGyD/GVqwfY 0DD4SIEbv49g6VjXa44eyi3JXNKt66wcWlFikzuQRC0gBvM= X-Google-Smtp-Source: AB8JxZrnN4kyAPRbtN9aW8/5L8jxKzdO8JXg4LWDmy6FIkFaTDq1wO7Npe9EbZ34OiaQA2dwt8Wqth+QBe1uQZ82Vm8= X-Received: by 2002:a62:ca98:: with SMTP id y24-v6mr1986456pfk.187.1525969859126; Thu, 10 May 2018 09:30:59 -0700 (PDT) MIME-Version: 1.0 References: <1f25e4e4c8fe45cf98c622807522e18b@SHYDEXMBX08.in.ril.com> In-Reply-To: <1f25e4e4c8fe45cf98c622807522e18b@SHYDEXMBX08.in.ril.com> From: Eric Evans Date: Thu, 10 May 2018 16:30:48 +0000 Message-ID: Subject: Re: Running multiple instances of Cassandra on each node in the cluster To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary="0000000000006446d0056bdc8b2f" --0000000000006446d0056bdc8b2f Content-Type: text/plain; charset="UTF-8" On Thu, May 10, 2018 at 2:25 AM wrote: > Dear community, > > Is it possible to have a cluster in Cassandra where each of the server is > running multiple instances of Cassandra(each instance is part of the same > cluster). > > I'm aware that if there's a single server in the cluster, then it's > possible to run multiple instances of Cassandra on it > , but is it also possible > to have multiple such servers in the cluster. If yes, how will the > configuration look like(listen address, ports etc)? > > Even if it was possible, I understand that there might not be any > performance benefits at all, just wanted to know if it's theoretically > possible. > We do this. It's not ideal from an operational POV, but as Jeff points out, if you have more hardware than it makes sense to give to a single Cassandra node, it's an option. Perhaps the biggest/most obvious thing to be aware of is that you need to use the network-topology strategy, and you need to ensure that all of the instances on a host are part of the same rack (otherwise you'll end up with replicas on the same machine, which isn't very redundant). If you are fluent in Puppet, our setup is here: https://github.com/wikimedia/puppet (Cassandra module here: https://github.com/wikimedia/puppet/tree/production/modules/cassandra) One of the things that Puppet module does, is write per-instance metadata as YAML files into /etc/cassandra-instances.d/, which we use in support of some tooling to ease some the operation burden. As an example, there is a `c-foreach-nt` script that iteratively issues nodetool commands against all configured instances (or a `c-any-nt` when you only need one, and don't care which), and a `c-foreach-restart` that iteratively restarts. Those are here: https://github.com/eevans/cassandra-tools-wmf -- Eric Evans eevans@wikimedia.org --0000000000006446d0056bdc8b2f Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Thu= , May 10, 2018 at 2:25 AM <Vis= hal1.Sharma@ril.com> wrote:

Dear community,

Is it possible to have a cluster in Cassandra where each= of the server is running multiple instances of Cassandra(each instance is = part of the same cluster).

I'm aware that if there's a single server in the= cluster, then=C2=A0it's possible to run multiple instances of Cassandra on it, but is i= t also possible to have multiple such servers in the cluster. If yes, how w= ill the configuration look like(listen address, ports etc)?

Even if it was possible, I understand that there might n= ot be any performance benefits at all, just wanted to know if it's theo= retically possible.

We do this.=C2= =A0 It's not ideal from an operational POV, but as Jeff points out, if = you have more hardware than it makes sense to give to a single Cassandra no= de, it's an option.

Perhaps the biggest/most obvious = thing to be aware of is that you need to use the network-topology strategy,= and you need to ensure that all of the instances on a host are part of the= same rack (otherwise you'll end up with replicas on the same machine, = which isn't very redundant).

If you are fluent in Pup= pet, our setup is here: htt= ps://github.com/wikimedia/puppet (Cassandra module here: https:/= /github.com/wikimedia/puppet/tree/production/modules/cassandra)

=
One of the things that Puppet module does, is write per-instance= metadata as YAML files into /etc/cassandra-instances.d/, which we use in s= upport of some tooling to ease some the operation burden.=C2=A0 As an examp= le, there is a `c-foreach-nt` script that iteratively issues nodetool comma= nds against all configured instances (or a `c-any-nt` when you only need on= e, and don't care which), and a `c-foreach-restart` that iteratively re= starts.=C2=A0 Those are here: https://github.com/eevans/cassandra-tools-wmf


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