Re: Issue when deleting Cassandra rowKeys.

2013-01-27 Thread Kasun Weranga
Hi, On Sun, Jan 27, 2013 at 12:05 AM, Michael Kjellman wrote: > What is your gc_grace set to? > Thanks for the info. I tried setting GcGraceSeconds for the column family to 0 since I have only one Cassandra node. still I can see the same behavior. ColumnFamily: bam_phone_retail_store_kpi

Re: Issue when deleting Cassandra rowKeys.

2013-01-27 Thread Kasun Weranga
Hi, After running compaction tombstones get removed. So It seems like only setting GC grace seconds to lower value is not enough. Am I correct ? Thanks, Kasun On Sun, Jan 27, 2013 at 1:31 PM, Kasun Weranga wrote: > Hi, > > On Sun, Jan 27, 2013 at 12:05 AM, Michael Kjellman < > mkjell...@barrac

Denormalization

2013-01-27 Thread Fredrik Stigbäck
Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle up

Re: Denormalization

2013-01-27 Thread Hiller, Dean
There is a really a mix of denormalization and normalization. It really depends on specific use-cases. To get better help on the email list, a more specific use case may be appropriate. Dean On 1/27/13 2:03 PM, "Fredrik Stigbäck" wrote: >Hi. >Since denormalized data is first-class citizen in

Re: Denormalization

2013-01-27 Thread Fredrik Stigbäck
I don't have a current use-case. I was just curious how applications handle and how to think when modelling, since I guess denormalization might increase the complexity of the application. Fredrik 2013/1/27 Hiller, Dean : > There is a really a mix of denormalization and normalization. It really

Re: Denormalization

2013-01-27 Thread Adam Venturella
In my experience, if you foresee needing to do a lot of updates where a "master" record would need to propagate its changes to other records, then in general a non-sql based data store may be the wrong fit for your data. If you have a lot of data that doesn't really change or is not linked in some

Re: Denormalization

2013-01-27 Thread Hiller, Dean
Things like PlayOrm exist to help you with half and half of denormalized and normalized data. There are more and more patterns out there of denormalization and normalization but allowing for scalability still. Here is one patterns page https://github.com/deanhiller/playorm/wiki/Patterns-Page

Re: Denormalization

2013-01-27 Thread Hiller, Dean
Oh and check out the last pattern "Scalable equals only index" which can allow you to still have normalized data though the pattern does denormalization just enough that you can 1. Update just two pieces of info (the users email for instance and the Xref table email as well). 2. Allow every

Re: Cassandra Consistency problem with NTP

2013-01-27 Thread Vijay
Just FYI, For one of the projects, i got around the NTP Drift problem by always reading more than i need, For example i want to read all the messages before x seconds then i would query cassandra for (x seconds + 500ms) then filter the duplicates in the client. Yes it does more network and yes cli

Re: Denormalization

2013-01-27 Thread Edward Capriolo
One technique is on the client side you build a tool that takes the even and produces N mutations. In c* writes are cheap so essentially, re-write everything on all changes. On Sun, Jan 27, 2013 at 4:03 PM, Fredrik Stigbäck < fredrik.l.stigb...@sitevision.se> wrote: > Hi. > Since denormalized dat

Re: Denormalization

2013-01-27 Thread Hiller, Dean
Sometimes this is true, sometimes not…..….We have a use case where we have an admin tool where we choose to do this denorm for ACL on permission checks to make permission checks extremely fast. That said, we have one issue with one object that too many children(30,000) so when someone gives a u

Re: Denormalization

2013-01-27 Thread Edward Capriolo
When I said that writes were cheap, I was speaking that in a normal case people are making 2-10 inserts what in a relational database might be one. 30K inserts is certainly not cheap. Your use case with 30,000 inserts is probably a special case. Most directory services that I am aware of OpenLDAP,

Re: Denormalization

2013-01-27 Thread Hiller, Dean
Agreed, was just making sure others knew ;). Dean From: Edward Capriolo mailto:edlinuxg...@gmail.com>> Reply-To: "user@cassandra.apache.org" mailto:user@cassandra.apache.org>> Date: Sunday, January 27, 2013 6:51 PM To: "user@cassandra.apache.org

Re: Issue when deleting Cassandra rowKeys.

2013-01-27 Thread aaron morton
Deletes must be written to disk otherwise they are lost. Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 28/01/2013, at 3:29 AM, Kasun Weranga wrote: > Hi, > > After running compaction tombstones get removed. So It

Flume-cassandra

2013-01-27 Thread Sri Ramya
hi, I am storing flume events in to cassandra by using simpleCassandraSink. when i am storing a single event to cassandra from flume collector source in Cassandra i am getting nearly 100 rows , in which 1 row is containg my data and other rows are blank. So how do i solve this problem . Please pro

Re: Flume-cassandra

2013-01-27 Thread Vijay
FYI, Not sure about this particular problem, https://github.com/Vijay2win/flume-cassandra-sink supports latest flume version, if you want to try it out. Regards, On Sun, Jan 27, 2013 at 8:05 PM, Sri Ramya wrote: > hi, > > I am storing flume events in to cassandra by using simpleCassandraSink

Accessing Metadata of Column Familes

2013-01-27 Thread Rishabh Agrawal
Hello, I wish to access metadata information on column families. How can I do it? Any ideas? Thanks and Regards Rishabh Agrawal NOTE: This message may contain information that is confidential, proprietary, privileged or otherwise protected by law. The me

RE: Accessing Metadata of Column Familes

2013-01-27 Thread Harshvardhan Ojha
Which API are you using? If you are using Hector use ColumnFamilyDefinition. Regards Harshvardhan OJha From: Rishabh Agrawal [mailto:rishabh.agra...@impetus.co.in] Sent: Monday, January 28, 2013 12:16 PM To: user@cassandra.apache.org Subject: Accessing Metadata of Column Familes Hello, I wish t

RE: Accessing Metadata of Column Familes

2013-01-27 Thread Rishabh Agrawal
Thank for the reply. I do not want to go by API route. I wish to access files and column families which store meta data information From: Harshvardhan Ojha [mailto:harshvardhan.o...@makemytrip.com] Sent: Monday, January 28, 2013 12:25 PM To: user@cassandra.apache.org Subject: RE: Accessing Metad

Re: Accessing Metadata of Column Familes

2013-01-27 Thread Abhijit Chanda
Just use DESCRIBE command in cqlsh. Refer to this link http://www.datastax.com/docs/1.1/references/cql/DESCRIBE On Mon, Jan 28, 2013 at 12:24 PM, Harshvardhan Ojha < harshvardhan.o...@makemytrip.com> wrote: > Which API are you using? > > If you are using Hector use ColumnFamilyDefinition. > >

RE: Accessing Metadata of Column Familes

2013-01-27 Thread Harshvardhan Ojha
You can get storage attributes from /data/system/ keyspace. From: Rishabh Agrawal [mailto:rishabh.agra...@impetus.co.in] Sent: Monday, January 28, 2013 12:42 PM To: user@cassandra.apache.org Subject: RE: Accessing Metadata of Column Familes Thank for the reply. I do not want to go by API route.