Re: Organize model for range scans in Cassandra

Hi Jon, Thanks for quick reply, I'm a newbie to Cassandra. Even though I made a mistake in previous mail. you got it right. I'll check what you've said. Cheers, Rajith. On Fri, Oct 18, 2013 at 11:47 AM, Jonathan Haddad wrote: > I'd avoid using super columns. I don't believe they're recommend

Re: Organize model for range scans in Cassandra

I'd avoid using super columns. I don't believe they're recommended anymore, and with CQL3 they aren't even supported (if you're interested in going that route). I think it's unlikely that you'll want a column family per company either. How many "ticker" entries do you plan on writing per company

Organize model for range scans in Cassandra

Hi all, I have a problem like this, I have stock transaction data, as follows. Ticker data: Company name: timestamp: closing price (N): (V) trades (N) : (V) .. . .. In my model : I want to execute ra

Re: Composite keys and composite columns

The explanation for Composite columns is muddied by verbage depending on whether you are talking about the thrift interface which tends to talk about things in low terms, or cql which tends to talk about things in higher level terms. At a thrift/low level, a composite column, really now called

Composite keys and composite columns

Hi, I'm looking for clarification on composite keys and composite columns. From what I've read with regards to composite keys, you have a collection of columns where of 'n' columns, the first n-1 form the composite primary key and the last column is the data for that composite key. Do I have th

nodetool status reporting dead node as UN

Hello, I seem to have gotten my cluster into a bit of a strange state. Pardon the rather verbose email, but there is a fair amount of background. I'm running a 3 node Cassandra 2.0.1 cluster. This particular cluster is used only rather intermittently for dev/testing and does not see particularly

Virtual node support for Hadoop workloads

Hello, According to DSE3.1 documentation [1], "DataStax recommends using virtual nodes only on data centers running purely Cassandra workloads. You should disable virtual nodes on data centers running either Hadoop or Solr workloads by setting num_tokens to 1.". There was a thread in this mailing

RE: about FlushWriter "All time blocked"

As an update to this thread, I modified the monitors exactly as Nate had suggested, and there have been no alerts since then (except in a case where we insanely loaded our cluster in test trying to determine our capacity) The “All time blocked” numbers are still pretty high though, eg. on one o

Re: Sorting keys for batch reads to minimize seeks

Unless I misunderstood your statement on sorting by row keys, Cassandra partitions rows across nodes based on row keys. Sorting a random set of keys will not help. If you know that you set of keys are on a particular node , then sorting might help. But I doubt that it is a sound practice, given th

Sorting keys for batch reads to minimize seeks

Hi, I am looking to somehow increase read performance on cassandra. We are still playing with configurations but I was thinking if there would be solutions in software that might help us speed up our read performance. E.g. one idea, not sure how sane that is, was to sort read-batches by row-

Re: DELETE does not delete :)

A couple questions: 1) How did you determine that the record is deleted on only one node? Are you looking for tombstones, or the original entry that was inserted? Note that when an item is deleted, the original entry can still be in an SSTABLE somewhere, and the tombstone can be in another SSTA

Re: NetworkTopologyStrategy and nodes ?

On Sat, Oct 12, 2013 at 9:08 AM, Andrew Cobley wrote: > > "In the following graphic, notice the tokens are assigned to alternating > racks. For more information, see *Generating > Tokens* > ." > > Seems to imply t

Re: DELETE does not delete :)

Hi Daniel, Nate. Thanks for your answers. We have *gc_grace_seconds=864000 *(which is the default, I believe). We've also checked the clocks - they are synchronized. 2013/10/16 Nate McCall > This is almost a guaranteed sign that the clocks are off in your cluster. > If you run the select query

Is read performance improved by moving more volatile data to different CF?

Hi, my rows consist of ~70 columns each, some containing small values, some containing larger amounts of content (think "small documents"). My data is occasionally updated and read several times per day as complete paging through all rows. The updates usually affect only about 10% of the smal