RE: about the hector client

It's ok -Original Message- From: raoyixuan (Shandy) [mailto:raoyix...@huawei.com] Sent: Wednesday, January 19, 2011 2:28 PM To: user@cassandra.apache.org Subject: RE: about the hector client I will try it again, thank you . -Original Message- From: Ashish [mailto:paliwalash...@g

Re: Keys must be written in ascending order

David, There was an issue similar to this reported during the 0.7 development https://issues.apache.org/jira/browse/CASSANDRA-1744 which was marked as duplicate with https://issues.apache.org/jira/browse/CASSANDRA-1743 It looks like the fix for 1743 did not make it into the 0.7 release,

Re: Multi-tenancy, and authentication and authorization

Opened https://issues.apache.org/jira/browse/CASSANDRA-2006 with the solution we had suggested on the MultiTenant wiki page. On Tue, Jan 18, 2011 at 11:56 PM, David Boxenhorn wrote: > I think tuning of Cassandra is overly complex, and even with a single > tenant you can run into problems with to

Re: Multi-tenancy, and authentication and authorization

> Right now there is a one-to-one mapping between memtables and SSTables. > Instead of that, would it be possible to have one giant memtable for each > Cassandra instance, with partial flushing to SSTs? I think a complication here is that, although I agree things need to be easier to tweak at leas

Re: Multi-tenancy, and authentication and authorization

I'm not sure that "you'd still want to retain the ability to individually control how flushing happens on a per-cf basis in order to cater to different workloads that benefit from different flushing behavior". It seems to me like a good system-wide algorithm that works dynamically, and takes into a

Re: Multi-tenancy, and authentication and authorization

+1 On Wed, Jan 19, 2011 at 10:35 AM, Stu Hood wrote: > Opened https://issues.apache.org/jira/browse/CASSANDRA-2006 with the > solution we had suggested on the MultiTenant wiki page. > > > On Tue, Jan 18, 2011 at 11:56 PM, David Boxenhorn wrote: > >> I think tuning of Cassandra is overly comple

Re: cassandra-cli: where a and b (works) vs. where b and a (doesn't)

On Jan 18, 2011, at 18:53, Nate McCall wrote: > When doing mixed types on slicing operations, you should use > ByteArraySerializer and handle the conversions by hand. > > We have an issue open for making this more graceful. Pls. have a look at http://groups.google.com/group/hector-dev/browse_t

Time-to-live on SuperColumns

Hi, I'm trying to use the time-to-live functionality, which I've patched into Cassandra 0.6.6. My problem is that my sstables are not emptying. When my data expires, they do reduce in size, but only by a fraction of what I expected. I've come to realise that this must be because I've set the

Re: Timeout Errors while running Hadoop over Cassandra

I was able to workaround this problem by modifying the ColumnFamilyRecordReader class from the org.apache.cassandra.hadoop package. Since the errors where TimeoutException, I added sleep and retry logic around rows = client.get_range_slices(keyspace, new ColumnParent(cfName), predicate,

should "nodetool repair " run periodic to keep consistency?

Just to ensure. So this should be done manually by the cluster operators? Thanks! --

Re: should "nodetool repair " run periodic to keep consistency?

On 19 January 2011 12:15, Donal Zang wrote: > Just to ensure. > So this should be done manually by the cluster operators? you could use crontab to automate it according to a schedule > > Thanks! > > -- > > > >

Re: Tombstone lifespan after multiple deletions

On Wed, Jan 19, 2011 at 12:59 AM, Zhu Han wrote: > > > On Wed, Jan 19, 2011 at 11:35 AM, Germán Kondolf > wrote: >> >> Yes, that's what I meant, but correct me if I'm wrong, when a deletion >> comes after another deletion for the same row or column will the gc-before >> count against the last one

Upgrading from 0.6 to 0.7.0

Hi, I've been looking around for how to upgrade from 0.6 to 0.7, and it looks like you need to shut down the whole cluster, plus upgrade the clients at the same time. Our live cassandra instances are currently running 0.6.4 with an ever growing database and need the new TTL feature available in 0

Re: Multi-tenancy, and authentication and authorization

As the actual problem is mostly related to the number of CFs in the system (may be number of the columns), I still believe that supporting exposing the Cassandra ‘as-is’ to a tenant is doable and suitable though need some fixes. That multi-tenancy model allows a tenant to use the programming model

Re: Multi-tenancy, and authentication and authorization

Yes, the way I see it - and it becomes even more necessary for a multi-tenant configuration - there should be completely separate configurations for applications and for servers. - Application configuration is based on data and usage characteristics of your application. - Server configuration is b

Re: Tombstone lifespan after multiple deletions

On Wed, Jan 19, 2011 at 8:41 PM, Germán Kondolf wrote: > On Wed, Jan 19, 2011 at 12:59 AM, Zhu Han wrote: > > > > > > On Wed, Jan 19, 2011 at 11:35 AM, Germán Kondolf < > german.kond...@gmail.com> > > wrote: > >> > >> Yes, that's what I meant, but correct me if I'm wrong, when a deletion > >> com

Re: Time-to-live on SuperColumns

In reply to my own question, I'm clearly talking nonsense. SuperColumns are cleared out when empty (because really, what's the difference from the client point of view?) and so setting TTL at the Column level is plainly good enough. This was actually solved by dropping G

Re: Keys must be written in ascending order

On Wed, Jan 19, 2011 at 2:26 AM, aaron morton wrote: > David, >        There was an issue similar to this reported during the 0.7 development > https://issues.apache.org/jira/browse/CASSANDRA-1744 which was marked as > duplicate with https://issues.apache.org/jira/browse/CASSANDRA-1743 It looks

Re: Tombstone lifespan after multiple deletions

On Wed, Jan 19, 2011 at 6:41 AM, Germán Kondolf wrote: > As the original example depicted clearly: > day 1 -> insert Row1.Col1 > day 2 -> delete Row1.Col1 > day 11 (before gc-grace-seconds) -> delete Row1.Col1 > > In the last command I've extended the life of a tombstone, maybe the > check before

Re: Tombstone lifespan after multiple deletions

On Wed, Jan 19, 2011 at 11:52 AM, Jonathan Ellis wrote: > On Wed, Jan 19, 2011 at 6:41 AM, Germán Kondolf > wrote: >> As the original example depicted clearly: >> day 1 -> insert Row1.Col1 >> day 2 -> delete Row1.Col1 >> day 11 (before gc-grace-seconds) -> delete Row1.Col1 >> >> In the last comma

Getting the version number

Is there any way to use nodetool (or anything else) to get the Cassandra version number of a deployed cluster?

Re: Getting the version number

in 0.7 nodetool has a `version` command. On Wed, Jan 19, 2011 at 4:09 PM, David Boxenhorn wrote: > Is there any way to use nodetool (or anything else) to get the Cassandra > version number of a deployed cluster? >

Re: Getting the version number

Yet another reason to move up to 0.7... Thanks. On Wed, Jan 19, 2011 at 5:27 PM, Daniel Lundin wrote: > in 0.7 nodetool has a `version` command. > > On Wed, Jan 19, 2011 at 4:09 PM, David Boxenhorn > wrote: > > Is there any way to use nodetool (or anything else) to get the Cassandra > > versio

MySQL Group By Equivalent for Cassandra ???

Hi all, Is there any MySQL Group By equivalent for Cassandra .. ??? regards -- Akshat Bakliwal Search Information and Extraction Lab IIIT-Hyderabad 09963885762 WebPage

Re: MySQL Group By Equivalent for Cassandra ???

Use map-reduce to run aggregate queries. Thanks, Shashank On Wed, Jan 19, 2011 at 7:55 AM, akshatbakli...@gmail.com < akshatbakli...@gmail.com> wrote: > Hi all, > Is there any MySQL Group By equivalent for Cassandra .. ??? > > regards > > -- > Akshat Bakliwal > Search Information and Extraction

Re: MySQL Group By Equivalent for Cassandra ???

http://howfuckedismydatabase.com/nosql/ Another option for "group by" is to simply store data in an aggregated form under a single key. Basically the principle of "store data how you want to query it": http://wiki.apache.org/cassandra/DataModel#Modeling_your_application Dave On 19 January 2011

Re: Keys must be written in ascending order

If you run sstablekeys it will tell you which key is out of orde -- assuming your index and data files contain the same keys, which if you have a corrupt sstable may or may not be the case. On Wed, Jan 19, 2011 at 1:10 AM, David King wrote: > I'm upgrading an 0.6 cluster to 0.7 in a testing envir

bootstrapping doesn't work for me

I use cassandra 0.7, and I have a cluster of two nodes. I have a first node 192.168.1.109 with in its yaml : initial_token: auto_bootstrap: false hinted_handoff_enabled: true partitioner: org.apache.cassandra.dht.RandomPartitioner seeds: - 192.168.1.109 listen_address: 192.168.1.109 rpc_addre

Basic question on distributed delete

I've been searching on wikis and FAQs for a definitive answer to this and haven't found it yet so I thought I'd ask people here. We have a 5-node cluster set up with a replication factor of 3. We're doing write operations (using batch mutates that include deletions) with a QUORUM consistency leve

Re: Basic question on distributed delete

> When we do a delete on a column in the above configuration, the call to the > server won't return until 2 of the 3 replicas are written to unless there's > an error.  That part is well-documented and understood.  The question I have > is whether or not the last of the 3 replica nodes gets the del

Re: should "nodetool repair " run periodic to keep consistency?

There is a lot of information on care and feeding of your Cassandra cluster available on the wiki operations page http://wiki.apache.org/cassandra/OperationsThere is also a section on how frequently repair should be run http://wiki.apache.org/cassandra/Operations#Frequency_of_nodetool_repairHope th

Re: Basic question on distributed delete

Okay, this helps. Cassandra works as I expected in the theoretically "pure" case (writing to the rest of the replicas in a background thread). I asked the question because we've been struggling to understand why we're seeing inconsistencies when we haven't had nodes go down, etc. (However, even

Re: Upgrading from 0.6 to 0.7.0

Unfortunately there are changes to the inter-node protocol which which make it impossible to run a mixed cluster. The TTL feature is one of the things that mean you also have to upgrade the client. The Columns returned and accepted by Cassandra will now expect to have a TTL field. AFAIK in theory T

Re: Time-to-live on SuperColumns

You can dump the contents of your SSTables using bin/sstable2json see http://wiki.apache.org/cassandra/Operations?#Import_.2BAC8_exportAFAIK deleting unneeded sstables is part of the GC process. If you trigger GC through JConsole you should see them disappear, the process logs the files that it del

Re: Basic question on distributed delete

Even without machines being down, the guarantee Cassandra gives you is exactly the ConsistencyLevel. Everything else is best-effort. In particular if you hammer Cassandra with more requests than it can fulfill, it will drop some instead of, say, running out of memory trying to queue them all up.

Re: Upgrading from 0.6 to 0.7.0

As far as I can tell, it is impossible to run a 0.6 client against a 0.7 server because the method signatures were changed in a non-backwards compatible way. Compare https://svn.apache.org/viewvc/cassandra/branches/cassandra-0.6/interface/cassandra.thrift?revision=964293&view=markup to https://

Re: Upgrading from 0.6 to 0.7.0

Your right, forgot about the change to binary keys :)Forgot what I said. AOn 20 Jan, 2011,at 11:01 AM, Anthony Molinaro wrote:As far as I can tell, it is impossible to run a 0.6 client against a 0.7 server because the method signatures were changed in a non-backwards compatible way. Compare http

Re: Upgrading from 0.6 to 0.7.0

Actually I didn't even notice that one :), the keyspace change and changing the field order was more noticeable. If instead 0.7 had done something like ColumnOrSuperColumn get(1:optional string keyspace, 2:optional string key, 3:required ColumnPath

Re: Upgrading from 0.6 to 0.7.0

On Wed, Jan 19, 2011 at 4:34 PM, Anthony Molinaro wrote: > Actually I didn't even notice that one :), the keyspace change and > changing the field order was more noticeable.  If instead 0.7 had > done something like > > ColumnOrSuperColumn get(1:optional string keyspace, >                        2

Does Cassandra support range queries on keys ?

Hello everyone, I'm new to dynamo. I'm looking to implement something similar to prefix search for keys (much like S3 allows you to list all the keys that match a certain prefix). Can I implement this with Cassandra? I'm using Hector as the client but would gladly go thrift is necessary. Thank

Re: Java cient

Perhaps. I use hector. I have an bit of rework to do moving from .6 to .7. This is something I wasn't anticipating in my earlier planning. Had Pelops been around when I started using Hector, I would have probably chosen it over Hector. The Pelops client seemed to be better conceived as far as progr

Re: about the hector client

Jonathan, If we make schema changes (like adding a keyspace) via the CLI, is it normal to keep getting this warning every time we start Cassandra: WARN 06:10:55,488 Schema definitions were defined both locally and in cassandra.yaml. Definitions in cassandra.yaml were ignored. 2011/1/18 Jonatha

Re: Java cient

The last set of API breakages we introduced in Hector were done with the intention of completely encapsulating Thrift. It was not a decision we made lightly as we knew it would kneecap a lot of people on their upgrade attempts. However, swallowing this bitter pill when we did has allowed us to off

Re: about the hector client

That's ok. If you want to stop it showing up, remove the schema definitions from Cassandra.yaml. Once they are loaded into the cluster the schema is stored in system column families, so the yaml definition is ignored. Aaron On 20/01/2011, at 12:50 PM, Cassy Andra wrote: > Jonathan, > > If we

Distributed counters

Hi, Does anyone use CASSANDRA-1072 counters patch with 0.7 stable branch? I need this functionality but can't wait until 0.8. Also, does Hector trunk version has any support for these counters? (this question is probably for hector-users group, but most of us anyway here). Many thanks, Rus

Re: Upgrading from 0.6 to 0.7.0

Really, my bad, I though they were, but maybe I'm confusing that with protobuf, I work with too many serialization formats :(. -Anthony On Wed, Jan 19, 2011 at 04:46:48PM -0600, Jonathan Ellis wrote: > On Wed, Jan 19, 2011 at 4:34 PM, Anthony Molinaro > wrote: > > Actually I didn't even notice t

Re: Upgrading from 0.6 to 0.7.0

So actually, how hard would it be to release a version of cassandra 6 which contained a second service Cassandra6 which was a replica of service Cassandra, then forward porting that service to Cassandra 7? That would allow and upgrade to do the following 1. rolling upgrade 0.6 server to server wi

Re: Java cient

My team switched our production stack from Hector to Pelops a while back, based largely on this admittedly subjective "programmer experience" bit. I've found Pelops' code and abstractions significantly easier to follow and integrate with, plus Pelops has had feature-parity with Hector for all of ou

Re: Multi-tenancy, and authentication and authorization

+1 Are there JIRAs for these requirements? I would like to contribute from my capacity. As per my understanding, to support some muti-tenant models, it is needed to qualified keyspaces' names, Cfs' names, etc. with the tenant namespace (or id). The easiest way to do this would be to modify corre

Re: Upgrading from 0.6 to 0.7.0

On Wed, Jan 19, 2011 at 10:15 PM, Anthony Molinaro wrote: > So actually, how hard would it be to release a version of cassandra 6 > which contained a second service Cassandra6 which was a replica of > service Cassandra, then forward porting that service to Cassandra 7? Off the top of my head, I d

Re: Java cient

Pelops is pretty thin wrapper for the Thrift API. It's thinness has both up and down sides; on the up side it's very easy to map functionality mentioned on the Cassandra API wiki page to functionality provided by Pelops, it is also relatively simple to add features (thanks to Alois^^ for indexing

Document Mapper for Ruby?

Hi all, Is anyone aware of a document mapper for Ruby similar to MongoMapper? Thanks heaps for your help. Kind regards, Joshua. -- http://twitter.com/jpartogi

Re: Upgrading from 0.6 to 0.7.0

an alternative might be a thrift proxy service... mapping the old thrift api onto the new. - Stephen --- Sent from my Android phone, so random spelling mistakes, random nonsense words and other nonsense are a direct result of using swype to type on the screen On 20 Jan 2011 05:11, "Jonathan Ellis