Given you’re using replication factor 1 (so each piece of data is only
going to get written to one node) something definitely seems wrong. Some
questions/ideas:
- are there any errors in the Cassandra logs or are you seeing any errors
at the client?
- is your test data distributed across your partition key or is it possible
all your test data is going to a single partition?
- have you tried manually running a few inserts to see if you get any
errors?
Cheers
Ben
On Thu, 22 Dec 2016 at 11:48 Branislav Janosik -T (bjanosik - AAP3 INC at
Cisco) <bjano...@cisco.com> wrote:
> Hi,
>
>
>
> - Consistency level is set to ONE
>
> - Keyspace definition:
>
> *"CREATE KEYSPACE IF NOT EXISTS onem2m " *+
> *"WITH replication = " *+
> *"{ 'class' : 'SimpleStrategy', 'replication_factor' : 1}"*;
>
>
>
> - yes, the client is on separate VM
>
> - In our project we use Cassandra API version 3.0.2 but the database
> (cluster) is version 3.9
>
> - for 2node cluster:
>
> first VM: 25 GB RAM, 16 CPUs
>
> second VM: 16 GB RAM, 16 CPUs
>
>
>
>
>
>
>
> *From: *Ben Slater <ben.sla...@instaclustr.com>
> *Reply-To: *"user@cassandra.apache.org" <user@cassandra.apache.org>
> *Date: *Wednesday, December 21, 2016 at 2:32 PM
> *To: *"user@cassandra.apache.org" <user@cassandra.apache.org>
> *Subject: *Re: Cassandra cluster performance
>
>
>
> You would expect some drop when moving to single multiple nodes but on the
> face of it that feels extreme to me (although I’ve never personally tested
> the difference). Some questions that might help provide an answer:
>
> - what consistency level are you using for the test?
>
> - what is your keyspace definition (replication factor most importantly)?
>
> - where are you running your test client (is it a separate box to
> cassandra)?
>
> - what C* version?
>
> - what are specs (CPU, RAM) of the test servers?
>
>
>
> Cheers
>
> Ben
>
>
>
> On Thu, 22 Dec 2016 at 09:26 Branislav Janosik -T (bjanosik - AAP3 INC at
> Cisco) <bjano...@cisco.com> wrote:
>
> Hi all,
>
>
>
> I’m working on a project and we have Java benchmark test for testing the
> performance when using Cassandra database. Create operation on a single
> node Cassandra cluster is about 15K operations per second. Problem we have
> is when I set up cluster with 2 or more nodes (each of them are on separate
> virtual machines and servers), the performance goes down to 1K ops/sec. I
> follow the official instructions on how to set up a multinode cluster – the
> only things I change in Cassandra.yaml file are: change seeds to IP address
> of one node, change listen and rpc address to IP address of the node and
> finally change endpoint snitch to GossipingPropertyFileSnitch. The
> replication factor is set to 1 when having 2-node cluster. I use only one
> datacenter. The cluster seems to be doing fine (I can see nodes
> communicating) and so is the CPU, RAM usage on the machines.
>
>
>
> Does anybody have any ideas? Any help would be very appreciated.
>
>
>
> Thanks!
>
>
>
>
