Re: Node tokens / data move
My understanding is that it is not possible to change the number of tokens after the node has been initialized. To do so you would first need to decommission the node, then start it clean with the appropriate num_tokens in the yaml. On Fri, Jul 12, 2013 at 9:17 PM, Radim Kolar wrote: > its possible to change num_tokens on node with data? > > i changed it and restarted node but it still has same amount in nodetool > status. >
Re: Node tokens / data move
> Pretty sure you can put the list in the yaml file too. Yup, sorry. initial_tokens can take a comma separated value Cheers - Aaron Morton Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 15/07/2013, at 9:44 AM, Eric Stevens wrote: > My understanding is that it is not possible to change the number of tokens > after the node has been initialized. To do so you would first need to > decommission the node, then start it clean with the appropriate num_tokens in > the yaml. > > > On Fri, Jul 12, 2013 at 9:17 PM, Radim Kolar wrote: > its possible to change num_tokens on node with data? > > i changed it and restarted node but it still has same amount in nodetool > status. >
Re: IllegalArgumentException on query with AbstractCompositeType
> Aaron Morton can confirm but I think one problem could be that to create an > index on a field with small number of possible values is not good. Yes. In cassandra each value in the index becomes a single row in the internal secondary index CF. You will end up with a huge row for all the values with false. And in general, if you want a queue you should use a queue. Cheers - Aaron Morton Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 14/07/2013, at 1:51 AM, Shahab Yunus wrote: > Aaron Morton can confirm but I think one problem could be that to create an > index on a field with small number of possible values is not good. > > Regards, > Shahab > > > On Sat, Jul 13, 2013 at 9:14 AM, Tristan Seligmann > wrote: > On Fri, Jul 12, 2013 at 10:38 AM, aaron morton > wrote: >> CREATE INDEX ON conv_msgdata_by_participant_cql(msgReadFlag); > On general this is a bad idea in Cassandra (also in a relational DB IMHO). > You will get poor performance from it. > > Could you elaborate on why this is a bad idea? > -- > mithrandi, i Ainil en-Balandor, a faer Ambar >
Re: Rhombus - A time-series object store for Cassandra
For those following along at home, recently another project in this space was announced https://github.com/deanhiller/databus Cheers - Aaron Morton Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 13/07/2013, at 4:01 PM, Ananth Gundabattula wrote: > Hello Rob, > > Thanks for the pointer. I have a couple of queries: > >> How does this project compare to the KairosDb project on github ( For one >> I see that Rhombus supports multi column query which is cool whereas >> kairos time series DB/OpenTSDB do not seem to have such a feature - >> although we can use the tags to achieve something similar ? ) > >> Are there any roll ups performed automatically by Rhombus ? > >> Can we control the TTL of the data being inserted ? > > I am looking at the some of the time series based projects for production > use preferably running on top of cassandra and was wondering if Rhombus > can be seen as a pure time series optimized schema or something more than > that ? > > Regards, > Ananth > > > > > On 7/12/13 7:15 AM, "Rob Righter" wrote: > >> Hello, >> >> Just wanted to share a project that we have been working on. It's a >> time-series object store for Cassandra. We tried to generalize the >> common use cases for storing time-series data in Cassandra and >> automatically handle the denormalization, indexing, and wide row >> sharding. It currently exists as a Java Library. We have it deployed >> as a web service in a Dropwizard app server with a REST style >> interface. The plan is to eventually release that Dropwizard app too. >> >> The project and explanation is available on Github at: >> https://github.com/Pardot/Rhombus >> >> I would love to hear feedback. >> >> Many Thanks, >> Rob >
Re: IllegalArgumentException on query with AbstractCompositeType
On Mon, Jul 15, 2013 at 12:26 AM, aaron morton wrote: > Aaron Morton can confirm but I think one problem could be that to create > an index on a field with small number of possible values is not good. > > Yes. > In cassandra each value in the index becomes a single row in the internal > secondary index CF. You will end up with a huge row for all the values with > false. > > And in general, if you want a queue you should use a queue. > This would seem to conflict with the advice to only use secondary indexes on fields with low cardinality, not high cardinality. I guess low cardinality is good, as long as it isn't /too/ low? -- mithrandi, i Ainil en-Balandor, a faer Ambar
Re: Rhombus - A time-series object store for Cassandra
Thanks for the pointer Aaron. Regards, Ananth On 15-Jul-2013, at 8:30 AM, "aaron morton" mailto:aa...@thelastpickle.com>> wrote: For those following along at home, recently another project in this space was announced https://github.com/deanhiller/databus Cheers - Aaron Morton Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 13/07/2013, at 4:01 PM, Ananth Gundabattula mailto:agundabatt...@threatmetrix.com>> wrote: Hello Rob, Thanks for the pointer. I have a couple of queries: How does this project compare to the KairosDb project on github ( For one I see that Rhombus supports multi column query which is cool whereas kairos time series DB/OpenTSDB do not seem to have such a feature - although we can use the tags to achieve something similar ? ) Are there any roll ups performed automatically by Rhombus ? Can we control the TTL of the data being inserted ? I am looking at the some of the time series based projects for production use preferably running on top of cassandra and was wondering if Rhombus can be seen as a pure time series optimized schema or something more than that ? Regards, Ananth On 7/12/13 7:15 AM, "Rob Righter" mailto:rob.righ...@pardot.com>> wrote: Hello, Just wanted to share a project that we have been working on. It's a time-series object store for Cassandra. We tried to generalize the common use cases for storing time-series data in Cassandra and automatically handle the denormalization, indexing, and wide row sharding. It currently exists as a Java Library. We have it deployed as a web service in a Dropwizard app server with a REST style interface. The plan is to eventually release that Dropwizard app too. The project and explanation is available on Github at: https://github.com/Pardot/Rhombus I would love to hear feedback. Many Thanks, Rob
too many open files
I'm running into a problem where instances of my cluster are hitting over 450K open files. Is this normal for a 4 node 1.2.6 cluster with replication factor of 3 and about 50GB of data on each node? I can push the file descriptor limit up, but I plan on having a much larger load so I'm wondering if I should be looking at something else…. Let me know if you need more info… Paul
Re: too many open files
Are you using leveled compaction? If so, what do you have the file size set at? If you're using the defaults, you'll have a ton of really small files. I believe Albert Tobey recommended using 256MB for the table sstable_size_in_mb to avoid this problem. On Sun, Jul 14, 2013 at 5:10 PM, Paul Ingalls wrote: > I'm running into a problem where instances of my cluster are hitting over > 450K open files. Is this normal for a 4 node 1.2.6 cluster with > replication factor of 3 and about 50GB of data on each node? I can push > the file descriptor limit up, but I plan on having a much larger load so > I'm wondering if I should be looking at something else…. > > Let me know if you need more info… > > Paul > > > -- Jon Haddad http://www.rustyrazorblade.com skype: rustyrazorblade
