cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jabbar Azam <>
Subject Re: Redundancy inside a cassandra node
Date Sat, 08 Nov 2014 09:43:18 GMT
Hello Alexey,

The node count is 20 per site and there will be two sites. RF=3. But since
the software isn't complete and the database code is going through a
rewrite we aren't sure about space requirements. The node count is only a
guess, bases on the number of dev nodes in use. We will have better
information when the rewrite is done and testing resumes.

The data will be time series data. It was binary blobs originally but we
have found that the new datastax c# drivers have improved alot in terms of
read performance.

I'm curious. What is your definition of commodity. My IT people seem to
think that the servers must be super robust. Personally I'm not sure if
that should be the case.

The node


Jabbar Azam

On 8 November 2014 02:56, Plotnik, Alexey <> wrote:

> Cassandra is a cluster itself, it's not necessary to have redundant each
> node. Cassandra has replication for that. And also Cassandra is designed to
> run in multiple data center - am think that redundant policy is applicable
> for you. Only thing from your saying you can deploy is raid10, other don't
> make any sense. As you are in stage of designing you cluster, please
> provide some numbers: how many data will be stored on each node, how many
> nodes would you have? What type of data will be stored in cluster: binary
> object o something time series?
> Cassandra is designed to run on commodity hardware.
> Отправлено с iPad
> > 8 нояб. 2014 г., в 6:26, Jabbar Azam <> написал(а):
> >
> > Hello all,
> >
> > My work will be deploying a cassandra cluster next year. Due to internal
> wrangling we can't seem to agree on the hardware. The software hasn't been
> finished, but management are asking for a ballpark figure for the hardware
> costs.
> >
> > The problem is the IT team are saying the nodes need to have multiple
> points of redundancy
> >
> > e.g. dual power supplies, dual nics, SSD's configured in raid 10.
> >
> >
> > The software team is saying that due to cassandras resilient nature, due
> to the way data is distributed and scalability that lots of cheap boes
> should be used. So they have been taling about self build consumer grade
> boxes with single nics, PSU's single SSDs etc.
> >
> > Obviously the self build boxes will cost a fraction of the price, but
> each box is not as resilient as the first option.
> >
> > We don;t use any cloud technologies, so that's out of the question.
> >
> > My question is what do people use in the real world in terms of node
> resiliancy when running a cassandra cluster?
> >
> > Write now the team is only thinking of hosting cassandra on the nodes.
> I'll see if I can twist their arms and see the light with Apache Spark.
> >
> > Obviously there are other tiers of servers, but they won't be running
> cassandra.
> >
> >
> >
> >
> >
> > Thanks
> >
> > Jabbar Azam

View raw message