Re: Is it possible to get list of row keys?

Does it help: https://github.com/rantav/hector/blob/master/core/src/test/java/me/prettyprint/cassandra/model/RangeSlicesQueryTest.java It uses setReturnKeysOnly()... Same for

Is it possible to get list of row keys?

Hi, Assuming the application does not know the list of keys that is stored inside cassandra, how would it be possible to get list of row keys? This list of row keys is going to be used to get a range of slices. Thank you for your help. -- http://twitter.com/jpartogi

Re: How does Cassandra handle failure during synchronous writes

Ritesh, There is no commit protocol. Writes may be persisted on some replicas even though the quorum fails. Here's a sequence of events that shows the "problem:" 1. Some replica R fails, but recently, so its failure has not yet been detected 2. A client writes with consistency > 1 3. The write go

Re: Cassandra nodes on EC2 in two different regions not communicating

If you login to one of the nodes, can you telnet to port 7000 on the other node? If not, then almost certainly it's a firewall/Security Group issue. You can find out the security groups for any node by logging in, and then running: % curl "http://169.254.169.254/latest/meta-data/security-groups"

Cassandra nodes on EC2 in two different regions not communicating

Hi, I am new to Cassandra. I m running Cassandra on EC2. I configured Cassandra cluster on two instances in different regions. But when I am trying the nodetool command with ring option, I am getting only single node. How to make these two nodes communicate with each other. I have already ope

Re: Cassandra deployment options on Terremark

Good thread on this recently: http://www.mail-archive.com/user@cassandra.apache.org/msg09020.html On Tue, Feb 22, 2011 at 10:38 PM, Sanjay Sharma wrote: > Hi All, > I am looking for Cassandra deployment options on Terremark eCloud. > Terremark uses NAS drive so that every machine instance gets al

Re: Does Cassandra use vector clocks

On Tue, Feb 22, 2011 at 7:37 PM, wrote: > Vector clocks was more of a Dynamo thing, I read a write up somewhere on some > of reasons why Cassandra puts this issue on the user but I can't locate it > currently unfortunately. Hope this helps. Basically: vector clocks tell you there was a conflic

Cassandra deployment options on Terremark

Hi All, I am looking for Cassandra deployment options on Terremark eCloud. Terremark uses NAS drive so that every machine instance gets allocated disk storage from this NAS, so not sure how the NAS replication model fits in with Cassandra replication model. The deployment size would be around 4-5

RE: Does Cassandra use vector clocks

Thanks Jeremy for the details. That helps. -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Does-Cassandra-use-vector-clocks-tp6054778p6055129.html Sent from the cassandra-u...@incubator.apache.org mailing list archive at Nabble.com.

RE: Does Cassandra use vector clocks

More a less yes you must handle the synchronization, this only really becomes an issue when multiple hosts hit Cassandra and want to hit the same row/column at the same time, which is certainly possible but may not be common depending on your use case. this has a bit of info on the column leve

Re: Does Cassandra use vector clocks

Thanks for the quick reply. I found this ticket https://issues.apache.org/jira/browse/CASSANDRA-580 which talks about vector clock support in Cassandra but it was marked as "won't fix". It would be insightful to know why it was rejected. If Cassandra relies on timestamps, does it mean that client

Re: Does Cassandra use vector clocks

It doesn't, where a time component is needed you must submit your own timestamp or clock, ie on an insert. - Original Message - From: tijoriwala.ritesh To: cassandra-u...@incubator.apache.org Sent: Tue Feb 22 19:59:56 2011 Subject: Does Cassandra use vector clocks Hi, I searched onli

Re: Does Cassandra use vector clocks

NO it doesn't. Instead of using vector clock, it checks the column timestamps. On Wed, Feb 23, 2011 at 11:59 AM, tijoriwala.ritesh wrote: > > Hi, > I searched online but couldn't get a detailed document on whether Cassandra > uses vector clocks or not? If yes, how does it work. Any pointers to de

Does Cassandra use vector clocks

Hi, I searched online but couldn't get a detailed document on whether Cassandra uses vector clocks or not? If yes, how does it work. Any pointers to details will be appreciated. Thanks, Ritesh -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Does

Re: Error when bringing up 3rd node

Could someone please help me understand why this might have happened? -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Error-when-bringing-up-3rd-node-tp6041409p6054768.html Sent from the cassandra-u...@incubator.apache.org mailing list archive at

Performance tunning

I have completed intial evaluation of cassandra. There are few things that I am still not comfortable with since I don't clearly understand them. Have couple of questions: 1) When developing large applications and designing the data model, keys etc what specifically are the things that one shoul

How scalable are automatic secondary indexes in Cassandra 0.7?

Hi, As far as I understand automatic secondary indexes are generated for node local data. In this case query by secondary index involve all nodes storing part of column family to get results (?) so (if i am right) if data is spread across 50 nodes then 50 nodes are involved in single query? How f

Re: Distribution Factor: part of the solution to many-CF problem?

On Tue, Feb 22, 2011 at 2:49 PM, Aaron Morton wrote: >> The single partitioner is "baked in" > That was my point. > > You could perhaps write a partitioner that considers the CF when deciding > what nodes to put data on. Off the top of my head the partitioner is not told > about the  CF the key

Re: TTL on a Column

On Tue, Feb 22, 2011 at 2:02 PM, wrote: > What units is this specified in milliseconds? > Seconds. -- Tyler Hobbs Software Engineer, DataStax Maintainer of the pycassa Cassandra Python client library

TTL on a Column

What units is this specified in milliseconds? ___ This e-mail may contain information that is confidential, privileged or otherwise protected from disclosure. If you are not an intended recipient of this e-mail, do not duplicate or redistribute it by

Re: Distribution Factor: part of the solution to many-CF problem?

> The single partitioner is "baked in" That was my point. You could perhaps write a partitioner that considers the CF when deciding what nodes to put data on. Off the top of my head the partitioner is not told about the CF the key is storing in. Aaron On 23/02/2011, at 6:01 AM, Edward Caprio

Re: Replicate changes from DC1 to DC2, but not from DC2 to DC1

That would cause a lot of subtle breakage, e.g. confusing Repair. 2011/2/22 Héctor Izquierdo Seliva : > El mar, 22-02-2011 a las 08:46 +1300, Aaron Morton escribió: >> Take a look at the NetworkTopologyStrategy and/or the RackInferringSnitch >> together they  decide where to place replicas. It's

Re: 0.7.2 slow memtables flushing

Absolutely right. (So, it's really a write-time slowdown, not read-time.) Created https://issues.apache.org/jira/browse/CASSANDRA-2218 for the fix. Thanks a lot for tracking that down! 2011/2/22 Ivan Georgiev : > Hi, yes, you are absolutely right, i overlooked that. > I am sending directly as i

Re: Help with Error on reading sstable

On Tue, Feb 22, 2011 at 4:32 AM, Jake Maizel wrote: > I'm getting this error after a space problem caused issues during a > repair operation on one of six nodes in our cluster: > ... > I am thinking that there was a failure with writing out an SSTable > because of space and now its corrupt. If th

Re: Distribution Factor: part of the solution to many-CF problem?

On Mon, Feb 21, 2011 at 5:14 PM, David Boxenhorn wrote: > No, that's not what I mean at all. > > That message is about the ability to use different partitioners for > different CFs, say, RandomPartitioner for one, OPP for another. > > I'm talking about defining how many nodes a CF should be distri

Re: Does servers with different capacities in a cluster affect the overall performance?

On Tue, Feb 22, 2011 at 5:13 AM, XiaoboGu wrote: > I mean servers with different CPU cores ,memory, or disk space, does > Cassandra allow this kind of configuration? This is allowed but managing this may be more difficult in production. Most settings are applied globally at the column family leve

Re: Exceptions on 0.7.0

Thanks, Shimi. I'll keep you posted if we make progress. Riptano is working on this problem too. On Tue, Feb 22, 2011 at 3:30 PM, shimi wrote: > I didn't solved it. > Since it is a test cluster I deleted all the data. I copied some sstables > from my production cluster and I tried again, this ti

Re: Exceptions on 0.7.0

I didn't solved it. Since it is a test cluster I deleted all the data. I copied some sstables from my production cluster and I tried again, this time I didn't have this problem. I am planing on removing everything from this test cluster. I will start all over again with 0.6.x , then I will load it

Help with Error on reading sstable

I'm getting this error after a space problem caused issues during a repair operation on one of six nodes in our cluster: 2011-02-22_11:54:50.26788 'ERROR [ROW-READ-STAGE:305] 11:54:50,267 CassandraDaemon.java:87 Uncaught exception in thread Thread[ROW-READ-STAGE:305,5,main] 2011-02-22_11:54:50.267

Re: Exceptions on 0.7.0

Shimi, I am getting the same error that you report here. What did you do to solve it? David On Thu, Feb 10, 2011 at 2:54 PM, shimi wrote: > I upgraded the version on all the nodes but I still gets the Exceptions. > I run cleanup on one of the nodes but I don't think there is any cleanup > goin

Re: Can I get a range of not deleted rows?

To make it short... No. You can only check if the Row contains at least one Column to understand if its a Tombstone or not.. Bye, Norman 2011/2/22 Joshua Partogi : > Hi there. > > It seems that when I fetch a range of rows, cassandra also includes > rows that has been deleted. Is it possible to

Can I get a range of not deleted rows?

Hi there. It seems that when I fetch a range of rows, cassandra also includes rows that has been deleted. Is it possible to only get rows that has not been deleted? Thanks for your help. Kind regards, Joshua. -- http://twitter.com/jpartogi

Does servers with different capacities in a cluster affect the overall performance?

I mean servers with different CPU cores ,memory, or disk space, does Cassandra allow this kind of configuration?

Reads and memory usage clarification

Hello, Write path is perfectly documented in architecture overview. I need Reads to be clarified: How memory is used 1. When data is in the Memtable 2. When data is in the SSTable How cache is used alongside with Memtable? Are records created in the Memtable from writes only or from reads also