Re: Modeling nested collection with C* 2.0

Ahmed, Just using text and serializing as Json is the easy way and a common approach. However, this list is for Cassandra commiter discussion, please be so kind as to use the regular user list for data modeling questions or for any future responses to this email thread. Regards, Ryan Svihla

Re: Modeling nested collection with C* 2.0

Hi Ahmed, I think modelling them as a map where you can 'label' your emails or addresses sounds like a good option. More info here: https://docs.datastax.com/en/cql/3.1/cql/cql_using/use_map_t.html Regards Carlos Alonso | Software Engineer | @calonso On 28 January

Re: Modeling nested collection with C* 2.0

Generally, you should use clustering columns to model nested structures, unless they really are simply list/map structures. But, first, as with all data modeling in Cassandra, start by looking at how you intend to query the data. Do you need to query individual addresses, email addresses, streets,

RE: Modeling nested collection with C* 2.0

I need to query all columns by the userid. For example: Select * from users where userid = 123; frozen UDT don’t exist in Cassandra 2.0 ☹ De : Jack Krupansky [mailto:jack.krupan...@gmail.com] Envoyé : jeudi 28 janvier 2016 16:38 À : user@cassandra.apache.org Objet : Re: Modeling nested collecti

Read operations freeze for a few second while adding a new node

Hi, We are struggling with a problem that when adding nodes around 5% read operations freeze (aka time out after 1 second) for a few seconds (10-20 seconds). It might not seems much, but at the order of 200k requests per second that's quite big of disruption. It is well documented and known that

Re: Modeling nested collection with C* 2.0

Maps and Sets have a hard limit of 65536 elements and you always need to get the full collection even if you are only interested in few elements. They are well suited to denormalize small datasets but above that it is better to use Clustering Columns to model these kind of data. Best, Lorand On T

Re: Read operations freeze for a few second while adding a new node

If you've got a read heavy workload you should check out http://blakeeggleston.com/cassandra-tuning-the-jvm-for-read-heavy-workloads.html On Thu, Jan 28, 2016 at 8:11 AM Lorand Kasler wrote: > Hi, > > We are struggling with a problem that when adding nodes around 5% read > operations freeze (a

Are aggregate functions done in parallel?

Does Cassandra paralelizes aggregate functions? Have a new project with potentially 200 to 300 million rows per month that I need to do aggregates on. Wondering if Cassandra would be a good match.

Re: Read operations freeze for a few second while adding a new node

Is this during streaming plan setup (is your 10-20 second time of impact approximately 30 seconds from the time you start the node that’s joining the ring), or does it happen for the entire time you’re joining the node to the ring? If so, there’s a chance it’s GC related – the streaming plan co

Re: Any excellent tutorials or automated scripts for cluster setup on EC2?

If you use Chef, there's this cookbook: https://github.com/michaelklishin/cassandra-chef-cookbook It's not perfect, but you can make a wrapper cookbook pretty easily to fix/extend it to do anything you need. On Wed, Jan 27, 2016 at 11:25 PM, Richard L. Burton III wrote: > I'm curious to see if

Re: Read operations freeze for a few second while adding a new node

Hi Lorand, Do you see any different gc pattern during these 20 seconds? In 2.0.x, memtable create lot of heap pressure. So in a way, reads are not isolated from writes. Frankly speaking, I would have accepted 20 second slowness as scaling is one time activity. But may be your business case doesnt

Re: Are aggregate functions done in parallel?

You can read this: http://www.doanduyhai.com/blog/?p=1876 and this: http://www.doanduyhai.com/blog/?p=2015 Long story short, UDF and UDA computation is Cassandra is not distributed. All the values are retrieved first on the coordinator node (to apply the last write win reconciliation logic) before

Re: Rename Keyspace offline

Thank you all for your replies. My main objective was not to change my client. After your answers it makes a lot of sense to modify my client in a way to make it accept different key space name. This way I will no longer need to rename a key space I simply need to develop a way to tell my client

Session timeout

Greetings, Does Cassandra support session timeout? If so, where can I find this configuration switch? If not, what kind of hook I can use to write my out code, terminating session in so many seconds of inactivity? Thanks, Oleg

Security labels

Greetings, Does Cassandra support security label concept? If so, where can I read on how it should be applied? Thanks, Oleg

Cassandra Connection Pooling

Hi, I'm looking for some good info on connection pooling, using JBoss. Is this something that needs to be configured within JBoss, or is it handled directly by the Cassandra classes themselves? Thanks. Bill

Re: Cassandra Connection Pooling

It's typically handled by your client (e.g. https://docs.datastax.com/en/latest-java-driver/index.html) along with retries, timeouts and all the other things you would put in your datasource config for a SQL database in JBoss. On Thu, Jan 28, 2016 at 5:31 PM, KAMM, BILL wrote: > Hi, I’m looking

Re: Cassandra Connection Pooling

On Thu, Jan 28, 2016 at 4:31 PM, KAMM, BILL wrote: > Hi, I’m looking for some good info on connection pooling, using JBoss. Is > this something that needs to be configured within JBoss, or is it handled > directly by the Cassandra classes themselves? Thanks. > > > > > This thread was on the J

Wide row in Cassandra

Hi all, I've found something in Internet, but still want to consult with your expertise. I'm designing a table, the object model will be like, class Data{ String uuid;//partition key String value1; String value2; ... String valueN; Map mapValues; } For one

Re: Wide row in Cassandra

As usual, the first step should be to example your queries and use them as the guide to data modeling. So... how do you need to access the data? What columns do you need to be able to query on vs. merely return? What data needs to be accessed at the same time? What data does not need to be accessed

Re: Security labels

Cassandra has support for authentication security, but I'm not familiar with a security label. Can you describe what you want to do? Patrick On Thu, Jan 28, 2016 at 2:26 PM, oleg yusim wrote: > Greetings, > > Does Cassandra support security label concept? If so, where can I read on > how it sho

Detailed info on how inter dc rep works

If I have a single client publishing to a cluster with replication to a second cluster in another dc, then do the changes become visible in the second dc in the same order that they became visible in the first dc?

Re: Detailed info on how inter dc rep works

John, There was a thread last month about this topic. https://mail-archives.apache.org/mod_mbox/incubator-cassandra-user/201512.mbox/%3CCABWW=xw9obk+w-4efpymnpo_fy8dbilbgv2fk-9xre7ydy2...@mail.gmail.com%3E On Thu, Jan 28, 2016 at 7:51 PM, John Lonergan wrote: > If I have a single client publ

Re: Security labels

Patrick, Absolutely. Security label is mechanism of access control, utilized by MAC (mandatory access control) model, and not utilized by DAC (discretionary access control) model, we all are used to. In database content it is illustrated for instance here: http://www.postgresql.org/docs/current/st

Logging connect/disconnect

Greetings, What is the right way to configure Cassandra logging, so it would log all the connects and disconnects? Thanks, Oleg

Re: Wide row in Cassandra

Thanks Jack. the columns to be used for query will be 'uuid' and 'key' in mapValues. For value1 to valueN, and Double in mapValues will be merely return. there are 2 scenarios to query. 1. Query for value, it can be any one from value1 to valueN. The query criteria will be 'uuid'. 2. Query for th

Call for Book Chapter

*Respected Sir/Madam,Book Chapter proposal are invited for the Edited book titled "NoSQL: Database for Storage and Retrieval of data in Cloud" to be published by CRC Press Taylor & Francis Group,Florida 33487, USA in the following topic: 1. Multi-model Databases, NewSQL, Time Series Databases, Data

Re: Wide row in Cassandra

This data model should do the job Create table Data ( text uuid; text value1 static; text value2 static; ... text valueN static; text mapKey; Double mapValue; primary key(key, mapKey); ); Warning, value1... valueN being static, there will be a 1:1 relationship between them

Re: Wide row in Cassandra

static column is exactly what I want! Thank you Duyhai! On Fri, 29 Jan 2016 07:22 DuyHai Doan wrote: > This data model should do the job > > Create table Data ( >text uuid; >text value1 static; >text value2 static; >... >text valueN static; >text mapKey; >Double mapV