Re: Large results and network round trips

For this scenario, remove disk speed from the equation. Assume the row is completely in Row Cache. Also lets assume Read.ONE. With this information I would be looking to determine response size/maximum requests second/max latency. I would use this to say "You want to do 5,000 reads/sec, on a GigaB

Re: constant CMS GC using CPU time

On Thu, Oct 25, 2012 at 4:15 AM, aaron morton wrote: > This sounds very much like "my heap is so consumed by (mostly) bloom >> filters that I am in steady state GC thrash." >> > > Yes, I think that was at least part of the issue. > > > The rough numbers I've used to estimate working set are: > >

Re: Large results and network round trips

I dont have any sample data on this, but read latency will depend on these 1) Consistency level of the read 2) Disk speed. Also you can look at the Netflix client as it makes the co-ordinator node same as the node which holds that data. This will reduce one hop. On Thu, Oct 25, 2012 at 9:04 AM, E

Re: High bandwidth usage between datacenters for cluster

Use placement_strategy = 'org.apache.cassandra.locator.NetworkTopologyStrategy' and also fill the topology.properties file. This will tell cassandra that you have two DCs. You can verify that by looking at output of the ring command. If you DCs are setup properly, only one request will go over WAN

Re: High bandwidth usage between datacenters for cluster

Use the datacenter replication strategy and try it with that so you tell cassandra all your data centers, racks, etc. Dean From: Bryce Godfrey mailto:bryce.godf...@azaleos.com>> Reply-To: "user@cassandra.apache.org" mailto:user@cassandra.apache.org>> Date: Thu

Re: What does ReadRepair exactly do?

manuzhang wrote > read quorum doesn't mean we read newest values from a quorum number of > replicas but to ensure we read at least one newest value as long as write > quorum succeeded beforehand and W+R > N. I beg to differ here. Any read/write, by definition of quorum, should have at least n/2 +

High bandwidth usage between datacenters for cluster

We have a 5 node cluster, with a matching 5 nodes for DR in another data center. With a replication factor of 3, does the node I send a write too attempt to send it to the 3 servers in the DR also? Or does it send it to 1 and let it replicate locally in the DR environment to save bandwidth ac

Re: What does ReadRepair exactly do?

read quorum doesn't mean we read newest values from a quorum number of replicas but to ensure we read at least one newest value as long as write quorum succeeded beforehand and W+R > N. On Fri, Oct 26, 2012 at 12:00 AM, Hiller, Dean wrote: > Kind of an interesting question > > I think you are sa

Large results and network round trips

Hello all, Currently we implement wide rows for most of our entities. For example: user { event1=>x event2=>y event3=>z ... } Normally the entires are bounded to be less then 256 columns and most columns are small in size say 30 bytes. Because the blind write nature of Cassandra it is possib

Re: What does ReadRepair exactly do?

Kind of an interesting question I think you are saying if a client read resolved only the two nodes as said in Aaron's email back to the client and read -repair was kicked off because of the inconsistent values and the write did not complete yet and I guess you would have two nodes go down to lose

Re: Java 7 support?

I am using the Sun JDK. There are only two issues I have found unrelated to Cassandra. 1) DateFormat is more liberal mmDD vs yyymmdd If you write an application with java 7 the format is forgiving with DD vs dd. Yet if you deploy that application to some JDK 1.6 jvms it fails 2) Ran into some

Re: Keeping the record straight for Cassandra Benchmarks...

Yes another "benchmark" with 100,000,000 rows on EC2 machines probably less powerful then my laptop. The benchmark might as well have run 4 vmware instances on the same desktop. On Thu, Oct 25, 2012 at 7:40 AM, Brian O'Neill wrote: > People probably saw... > http://www.networkworld.com/cgi-bin/m

Keeping the record straight for Cassandra Benchmarks...

People probably saw... http://www.networkworld.com/cgi-bin/mailto/x.cgi?pagetosend=/news/tech/2012/102212-nosql-263595.html To clarify things take a look at... http://brianoneill.blogspot.com/2012/10/solid-nosql-benchmarks-from-ycsb-w-side.html -brian -- Brian ONeill Lead Architect, Health Mark

Re: constant CMS GC using CPU time

> This sounds very much like "my heap is so consumed by (mostly) bloom > filters that I am in steady state GC thrash." > > Yes, I think that was at least part of the issue. The rough numbers I've used to estimate working set are: * bloom filter size for 400M rows at 0.00074 fp without java fudge

Re: constant CMS GC using CPU time

> Regarding memory usage after a repair ... Are the merkle trees kept around? > They should not be. Cheers - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 24/10/2012, at 4:51 PM, B. Todd Burruss wrote: > Regarding memory usage after a repair .

Re: What does ReadRepair exactly do?

It's import to point out the difference between Read Repair, in the context of the read_repair_chance setting, and Consistent Reads in the context of the CL setting. If RR is active on a request it means the request is sent to ALL UP nodes for the key and the RR process is ASYNC to the request

Re: how to stop hinted handoff

Thanks, that did the trick! *Tamar Fraenkel * Senior Software Engineer, TOK Media [image: Inline image 1] ta...@tok-media.com Tel: +972 2 6409736 Mob: +972 54 8356490 Fax: +972 2 5612956 On Thu, Oct 11, 2012 at 3:42 AM, Roshan wrote: > Hello > > You can delete the hints from JConsole