Re: Problems with adding datacenter and schema version disagreement

OK, I see, so the data files stay in place, i have to just stop cassandra on whole cluster, remove system schema and then start cluster and recreate all keyspaces with all column families? Data will be than loaded automatically from existing ssstables, right? So one more question: what about KS sys

Cassandra slow on some reads

Hello all, Here is the environment: I have a 6 node Cassandra cluster. On each node I have: - 32 G RAM - 24 G RAM for cassa - ~150 - 200 MB/s disk speed - tomcat 6 with axis2 webservice that uses the datastax java driver to make asynch reads / writes  - replication factor for the keyspace is 3 (

Re: Cassandra slow on some reads

Is row cache enabled on this CF? Try disabling it. Seems like you might have a very wide row there. Can you grep for GCInspector in your Cassandra log? 24G might be a bit too much for the Cassandra JVM, bogging down GC, and not leaving much to page cache ( 32G -24G - Tomcat ). I don’t quite und

Re: Cassandra slow on some reads

To add to this, if the 24G is the JVM limit, Cassandra will actually be using even more than this for bloom filters etc. that are managed off-heap. So the amount of page cache left is almost certainly inadequate. On 14 March 2014 13:01, Andras Szerdahelyi < andras.szerdahe...@ignitionone.com> wro

Re: Cassandra slow on some reads

Ok will try to reduce heap and see what happens. Thanks guys. I' get back with conclusions.https://overview.mail.yahoo.com?.src=iOS";>Sent from Yahoo Mail for iPhone

Re: Cassandra slow on some reads

Well the problem still persists. Giving cassandra 12G of heap and having a look at the table I saw that   caching='KEYS_ONLY' . Did not find how to disable caching for rows (I'm not sure if setting to 0 will disable it) On Friday, March 14, 2014 3:14 PM, Andras Szerdahelyi wrote: Is row

Re: CQL Select Map using an IN relationship

Hi Michael, Thanks for the feedback, all makes sense. If anyone wants me to raise a jira ticket for docs on (key1, key2) vs ((key1,key2)) and their implications, or fixing that if block in SelectStatement, let me know - though for the if block possibly best if that jira is raised by a C* expert s

Re: Dead node seen as UP by replacement node

Since the older node is not available i would ask you to assassinate the old node and then get the node new node to bootstrap. On Thu, Mar 13, 2014 at 10:56 PM, Paulo Ricardo Motta Gomes < paulo.mo...@chaordicsystems.com> wrote: > Yes, exactly. > > > On Thu, Mar 13, 2014 at 1:27 PM, Rahul Menon

Re: Cassandra slow on some reads

*If* you do not need to do range queries on your 'timestam' (ts) column - *and* if you can change your schema (big if...), then you could move 'timestam' into the partition key like this (using your notation): PK((key String , timestam int), column1 string, col2 string) , list1 , list 2, list 3 .

Re: Cassandra slow on some reads

Hello, I can't go this way... this cf will be used for time ranges.  On Friday, March 14, 2014 5:10 PM, "Laing, Michael" wrote: If you do not need to do range queries on your 'timestam' (ts) column - and if you can change your schema (big if...), then you could move 'timestam' into the pa

Re: Dead node seen as UP by replacement node

Hmm, we considered that option but if the old node is assassinated, his range will be assigned to a neighbor that doesn't have the data, what will cause empty reads. What we did to solve the problem was to do a safe removal via "nodetool removenode ", wait some hours for neighbors to stream that no

Re: Problems with adding datacenter and schema version disagreement

On Fri, Mar 14, 2014 at 12:40 AM, olek.stas...@gmail.com < olek.stas...@gmail.com> wrote: > OK, I see, so the data files stay in place, i have to just stop > cassandra on whole cluster, remove system schema and then start > cluster and recreate all keyspaces with all column families? Data will > b

Re: Problems with adding datacenter and schema version disagreement

Ok, I'll do this during the weekend, I'll give you a feedback on Monday. Regards Aleksander 14 mar 2014 18:15 "Robert Coli" napisał(a): > On Fri, Mar 14, 2014 at 12:40 AM, olek.stas...@gmail.com < > olek.stas...@gmail.com> wrote: > >> OK, I see, so the data files stay in place, i have to just sto

Re: Cassandra slow on some reads

> > > > I have ~450 queries that are like this: SELECT * FROM table where key = > 'some string' and ts = some value; some value is close to present time. > > The problem: > > About 10 - 20 % of these queries take more than 5 seconds to execute, in > fact, the majority of those take around 10 second

ccm support for Windows

As of today, ccm supports Windows. It should work in both cygwin and the general command-prompt though there are some known issues right now which are documented in the README. If any Windows users are so inclined to test or tinker I'd be happy to field questions /

Re: ccm support for Windows

On Fri, Mar 14, 2014 at 11:23 AM, Josh McKenzie wrote: > As of today, ccm supports Windows. It > should work in both cygwin and the general command-prompt though there are > some known issues right now which are documented in the README. > > If any Windows users ar

Serial Consistency and Thrift API

Hello all, I am running some tests in my cluster and I wanted to try some of the new features of Cassandra like lightweight transactions and Serial Writes. Surprisingly I found out that Serial writes are not supported by the Thrift API. Is there any patch available or the only way to support them

Re: ccm support for Windows

The windows dtests take another pull request - this one incredibly minor - to fix some of the odd pathing in Windows. I'll get that in today. On Fri, Mar 14, 2014 at 1:29 PM, Robert Coli wrote: > On Fri, Mar 14, 2014 at 11:23 AM, Josh McKenzie < > josh.mcken...@datastax.com> wrote: > >> As of

Re: Serial Consistency and Thrift API

On Fri, Mar 14, 2014 at 11:59 AM, Panagiotis Garefalakis wrote: > I am running some tests in my cluster and I wanted to try some of the new > features of Cassandra like lightweight transactions and Serial Writes. > Surprisingly I found out that Serial writes are not supported by the > Thrift API.

Re: Serial Consistency and Thrift API

Recently I added CQL3 support to Hector, but I haven't had time to try out serial writes. On Fri, Mar 14, 2014 at 3:34 PM, Robert Coli wrote: > On Fri, Mar 14, 2014 at 11:59 AM, Panagiotis Garefalakis < > panga...@gmail.com> wrote: > >> I am running some tests in my cluster and I wanted to try

Re: ccm support for Windows

dtest changes are merged in. Have fun with that Rob. ;) The few I poked at weren't looking clean on Windows - there may be some timing / wait issues in ccm that aren't playing nice but it's a step in the right direction. I'm hoping to overhaul the Windows launching process before moving on to t

Cannot bootstrap replacement node

Hello, I'm having some trouble during bootstrap of a replacement node and I'm suspecting it could be a bug in Cassandra. I'm using C* 1.2.13, RF=2, with Vnodes disabled. Below is a simplified version of my ring: * n1 : token 100 * n2 : token 200 (DEAD) * n3 : token 300 * n4 : token 0 n2 has died

Re: Cannot bootstrap replacement node

On Fri, Mar 14, 2014 at 2:18 PM, Paulo Ricardo Motta Gomes < paulo.mo...@chaordicsystems.com> wrote: > My next and last approach is to manually copy the sstables via rsync from > n3 and start x with auto_bootstrap=false, but I really didn't want to use > this approach. Is it so hard to bootstrap a

Re: replication_factor: ?

On Fri, Mar 7, 2014 at 2:01 PM, Donald Smith < donald.sm...@audiencescience.com> wrote: > Robert, please elaborate why you say "To make best use of Cassandra, my > minimum recommendation is usually RF=3, N=6." > > > I surmise that with any less than 6 nodes, you'd likely perform better > with a s

Re: Possibly losing data with corrupted SSTables

On Wed, Feb 12, 2014 at 9:20 AM, Francisco Nogueira Calmon Sobral < fsob...@igcorp.com.br> wrote: > I've removed the corrupted sstables and 'nodetool repair' ran successfully > for the column family. I'm not sure whether or not we've lost data. > If you read/write at CL.ONE, there is a non-zero c

Re: supervisord and cassandra

FWIW, if you are using something like supervisor to ensure that cassandra auto-starts if it crashes, you should be aware that there are good reasons to not do that. https://issues.apache.org/jira/browse/CASSANDRA-2356 Discusses some of the cases, but it basically sums to "starting a distributed s

Re: Dangers of "sudo swapoff --all"

On Thu, Feb 13, 2014 at 2:57 PM, Donald Smith < donald.sm...@audiencescience.com> wrote: > I followed the recommendations at > http://www.datastax.com/documentation/cassandra/2.0/webhelp/index.html#cassandra/install/installRecommendSettings.htmland > did: > > > > $ sudo swapoff -all > > > > on e