Re: How can I scale my read rate?

2017-03-27 Thread Alexander Dejanovski
By default the TokenAwarePolicy does shuffle replicas, and it can be disabled if you want to only hit the primary replica for the token range you're querying : http://docs.datastax.com/en/drivers/java/3.0/com/datastax/driver/core/policies/TokenAwarePolicy.html On Mon, Mar 27, 2017 at 9:41 AM Avi

Re: How can I scale my read rate?

2017-03-27 Thread Avi Kivity
Is the driver doing the right thing by directing all reads for a given token to the same node? If that node fails, then all of those reads will be directed at other nodes, all oh whom will be cache-cold for the the failed node's primary token range. Seems like the driver should distribute

Re: How can I scale my read rate?

2017-03-26 Thread Anthony Grasso
Keep in mind there are side effects to increasing to RF = 4 - Storage requirements for each node will increase. Depending on the number of nodes in the cluster and the size of the data this could be significant. - Whilst the number of available coordinators increases, the number of

Re: How can I scale my read rate?

2017-03-26 Thread Eric Stevens
Yes, throughput for a given partition key cannot be improved with horizontal scaling. You can increase RF to theoretically improve throughput on that key, but actually in this case smart clients might hold you back, because they're probably token aware, and will try to serve that read off the

Re: How can I scale my read rate?

2017-03-23 Thread Alain Rastoul
On 24/03/2017 01:00, Eric Stevens wrote: Assuming an even distribution of data in your cluster, and an even distribution across those keys by your readers, you would not need to increase RF with cluster size to increase read performance. If you have 3 nodes with RF=3, and do 3 million reads,

Re: How can I scale my read rate?

2017-03-23 Thread Eric Stevens
Assuming an even distribution of data in your cluster, and an even distribution across those keys by your readers, you would not need to increase RF with cluster size to increase read performance. If you have 3 nodes with RF=3, and do 3 million reads, with good distribution, each node has served

Re: How can I scale my read rate?

2017-03-20 Thread Alain Rastoul
On 20/03/2017 22:05, Michael Wojcikiewicz wrote: Not sure if someone has suggested this, but I believe it's not sufficient to simply add nodes to a cluster to increase read performance: you also need to alter the ReplicationFactor of the keyspace to a larger value as you increase your cluster

Re: How can I scale my read rate?

2017-03-20 Thread Alain Rastoul
On 20/03/2017 02:35, S G wrote: 2) https://docs.datastax.com/en/developer/java-driver/3.1/manual/statements/prepared/ tells me to avoid preparing select queries if I expect a change of columns in my table down the road. The problem is also related to select * which is considered bad practice

Re: How can I scale my read rate?

2017-03-19 Thread James Carman
ng to > try. > If not, please do share some more details. > > > > > On Sat, Mar 18, 2017 at 2:00 PM, <j.kes...@enercast.de> wrote: > > +1 for executeAsync – had a long time to argue that it’s not bad as with > good old rdbms. > > > > > > > > Gesende

Re: How can I scale my read rate?

2017-03-19 Thread Alain Rastoul
On 19/03/2017 02:54, S G wrote: Forgot to mention that this vmstat picture is for the client-cluster reading from Cassandra. Hi SG, Your numbers are low, 15k req/sec would be ok for a single node, for a 12 nodes cluster, something goes wrong... how do you measure the throughput? As

Re: How can I scale my read rate?

2017-03-18 Thread S G
uteAsync – had a long time to argue that it’s not bad as with >>> good old rdbms. >>> >>> >>> >>> >>> >>> >>> >>> Gesendet von meinem Windows 10 Phone >>> >>> >>> >>> *Von: *Arvydas Jo

Re: How can I scale my read rate?

2017-03-18 Thread S G
meinem Windows 10 Phone >> >> >> >> *Von: *Arvydas Jonusonis <arvydas.jonuso...@gmail.com> >> *Gesendet: *Samstag, 18. März 2017 19:08 >> *An: *user@cassandra.apache.org >> *Betreff: *Re: How can I scale my read rate? >> >> >> >> ..

Re: How can I scale my read rate?

2017-03-18 Thread S G
dows 10 Phone > > > > *Von: *Arvydas Jonusonis <arvydas.jonuso...@gmail.com> > *Gesendet: *Samstag, 18. März 2017 19:08 > *An: *user@cassandra.apache.org > *Betreff: *Re: How can I scale my read rate? > > > > ..then you're not taking advantage of request p

AW: How can I scale my read rate?

2017-03-18 Thread j.kesten
+1 for executeAsync – had a long time to argue that it’s not bad as with good old rdbms. Gesendet von meinem Windows 10 Phone Von: Arvydas Jonusonis Gesendet: Samstag, 18. März 2017 19:08 An: user@cassandra.apache.org Betreff: Re: How can I scale my read rate? ..then you're not taking