London meetup - 16th July

The next London meetup is coming up on 16th July. We've got two speakers - Richard Churchill talking about his experiences rolling out Cassandra at ServiceTick and Tom Wilkie talking about real time analytics on top of Cassandra. http://www.meetup.com/Cassandra-London/events/69791362/ Dave

London meetup - upcoming events

Hi all, Those in the UK might be interested in the next Cassandra London events: Monday 20th February Two talks: Cassandra as an email storage system and CQL - then and now http://www.meetup.com/Cassandra-London/events/29569461/ Tuesday 6th March How Netflix uses Cassandra with Adrian

Cassandra London - Monday 21/11

Hi all, Quick note about our Cassandra London 1st birthday party! We'll be looking at what's changed in Cassandra over the past year, with talks on feature improvements, performance and Hadoop integration. Please come along if you're UK-based! It's a great chance to meet other Cassandra users.

Cassandra London: failure modes and HBase

Hi all, I'm pleased to announce our next Cassandra meetup on 5th September in London. http://www.meetup.com/Cassandra-London/events/29668191/ We will be looking at failure modes in Cassandra (how it deals with nodes failing and returning etc..) as well as a comparison with HBase. It's a great

July meetup in London

Hi all, If you're London based please come along to the Cassandra user group. This month we're going to be looking at how Cassandra compares with some other solutions (Riak and Mongo). This will be particularly interesting for anyone who is still at an early stage and wants to get more of an idea

Talk on DataStax Brisk on Monday at Cassandra London

Hi all, Any London-based people who are interested in Brisk should come along to the Cassandra London meetup on Monday. There will be a talk and live demo. http://www.meetup.com/Cassandra-London/events/16643691/ Dave

Seeking Cassandra in production speaker volunteers! (free beer on offer)

Hi all Influenced by the up and coming Redis in production meetup in London, I'm on the lookout for volunteers to speak at a Cassandra in production meetup (again, in London). You will get the satisfaction of becoming Internet famous, plus I will personally buy you a beer. Links:

London meetup tonight - CQL and Cassandra internals

Hi all, FYI: The next Cassandra London meetup is tonight at Skills Matter. The focus is Cassandra internals and CQL. http://www.meetup.com/Cassandra-London/events/15490573/ There will be three talks: 1. Lorenzo Alberton on Bloom Filters, Merkle Trees and some interesting variants 2. Andrew

Re: Cassandra London UG meetup Monday

could do a phone hookup? Ash On 19/03/2011, at 2:25 AM, Dave Gardner dave.gard...@visualdna.com wrote: Hi all, Anyone based in the UK may be interested in our user group meetup on Monday.  We will have talks on Hadoop integration and some performance data related to this. Please come

Cassandra London UG meetup Monday

Hi all, Anyone based in the UK may be interested in our user group meetup on Monday. We will have talks on Hadoop integration and some performance data related to this. Please come along if you'd like to meet other people using Cassandra or would like to learn more.

London meetup on Hadoop Integration

Hi all, This month's London user group will be on the topic of Hadoop integration. If anyone is interested in sharing knowledge about how they use Hadoop with Cassandra then please get in touch, there are some speaker slots available. If you'd like to learn more then please come along!

Re: cassandra as user-profile data store

the timeline, with rows of user-ids, and TimeUUID columns for each data-collection-time. Then some post-processing with Hadoop over the timelines for each user to build a Profile? Are you on 0.7 or 0.6.x? Dave Viner On Tue, Mar 1, 2011 at 1:31 AM, Dave Gardner dave.gard...@visualdna.comwrote

Re: cassandra as user-profile data store

Dave Tyler's answer already covers CFs etc.. We are using Cassandra to store user profile data for exactly the sort of use case you describe. We don't yet store _all_ the data in Cassandra; currently we are focusing on the stuff we need available for real-time access. We use Hadoop to analyse

Re: Use Cassandra to store 2 million records of persons

that, please share. Thanks and regards Surender Singh -- *Dave Gardner* Technical Architect [image: imagini_58mmX15mm.png] [image: VisualDNA-Logo-small.png] *Imagini Europe Limited* 7 Moor Street, London W1D 5NB [image: phone_icon.png] +44 20 7734 7033 [image: skype_icon.png] daveg79

Re: Upgrading from 0.6 to 0.7.0

What about executing writes against both clusters during the changeover? Interested in this topic because we're currently thinking about the same thing - how to upgrade to 0.7 without any interruption. Dave On 21 January 2011 09:20, Daniel Josefsson jid...@gmail.com wrote: No, what I'm

Re: MySQL Group By Equivalent for Cassandra ???

http://howfuckedismydatabase.com/nosql/ Another option for group by is to simply store data in an aggregated form under a single key. Basically the principle of store data how you want to query it: http://wiki.apache.org/cassandra/DataModel#Modeling_your_application Dave On 19 January 2011

Re: What is be the best possible client option available to a PHP developer for implementing an application ready for production environments ?

64bit system.  PHP is fairly slow.  PHP makes a few other things less easy to do.  If you're doing some pretty lightweight interaction with Cassandra through PHP, these might not be a problem for you. - Tyler -- *Dave Gardner* Technical Architect [image: imagini_58mmX15mm.png] [image

Re: Do you have a site in production environment with Cassandra? What client do you use?

appreciated ? Thanks Ertio -- *Dave Gardner* Technical Architect [image: imagini_58mmX15mm.png] [image: VisualDNA-Logo-small.png] *Imagini Europe Limited* 7 Moor Street, London W1D 5NB [image: phone_icon.png] +44 20 7734 7033 [image: skype_icon.png] daveg79 [image: emailIcon.png] dave.gard

Looking for London-based users of Cassandra

I am looking for London-based users of Cassandra who would be interested in giving a short talk on _how_ they make use of Cassandra, hopefully including details such as data layout, types of query, load etc.. This is for the Cassandra London user group -- this month we are planning to have more

Re: LA, Tokyo Cassandra trainings this week

We've also got Jake Luciani (@tjake) giving a talk at Cassandra London this Wednesday - this is a great opportunity to meet with other Cassandra users. There will be some free beer and food available. http://www.meetup.com/Cassandra-London/calendar/15351291/ Dave On 6 December 2010 17:05,

Re: Cluster fragility

and streaming/replication problems without rebooting. -- *Dave Gardner* Technical Architect [image: imagini_58mmX15mm.png] [image: VisualDNA-Logo-small.png] *Imagini Europe Limited* 7 Moor Street, London W1D 5NB [image: phone_icon.png] +44 20 7734 7033 [image: skype_icon.png] daveg79 [image

Re: row cache vs frequent row updates vs write through row cache

for these instead. -Brandon -- *Dave Gardner* Technical Architect [image: imagini_58mmX15mm.png] [image: VisualDNA-Logo-small.png] *Imagini Europe Limited* 7 Moor Street, London W1D 5NB [image: phone_icon.png] +44 20 7734 7033 [image: skype_icon.png] daveg79 [image: emailIcon.png] dave.gard

London meetup group

Hi all, We've been using Cassandra for some months now and have a cluster in production. To help us learn more about Cassandra and meet other people who are using it I have just launched the* London meetup* (partly prompted by the guys who launched the Israel and Bay Area groups recently). If

Advice on settings

-and-consistency#13 Is this true, or will read repair still hammer disks in all the machines with the data on? Again I guess it's better to have low RF so there are less copied of the data to inspect when doing read repair. Will this result in better read performance? Thanks dave -- *Dave Gardner

Re: Dazed and confused with Cassandra on EC2 ...

As a follow up to this conversation; we are still having issues with our Cassandra cluster on EC2. It *looks* to be related to Garbage Collection; however we aren't sure what the root cause of the problem is. Here is an extract from logs: INFO [GMFD:1] 2010-09-20 15:22:00,242 Gossiper.java

Re: Dazed and confused with Cassandra on EC2 ...

Nope - no swap enabled. top - 16:53:14 up 12 days, 6:11, 3 users, load average: 1.99, 2.63, 5.03 Tasks: 133 total, 1 running, 132 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 35840228k total, 33077580k used, 2762648k

Re: Dazed and confused with Cassandra on EC2 ...

One other question for the list: I gather GMFD is gossip stage - but what does this actually mean? Is it an issue to have 203 pending operations? Thanks Dave INFO [GC inspection] 2010-09-20 16:56:12,792 GCInspector.java (line 129) GC for ParNew: 127970 ms, 570382800 reclaimed leaving

Re: Thrift + PHP: help!

I'm happy to assist. Having a robust PHP implementation would help us greatly. Dave On Wednesday, August 18, 2010, Jeremy Hanna jeremy.hanna1...@gmail.com wrote: As Jonathan mentioned in his keynote at the Cassandra Summit, the thrift + php has some bugs and is maintainerless right now. Is

Very slow reads - connected to TBufferedTransport buffer sizes

Hi all I'm working on a PHP/Cassandra application. Yesterday we experienced a strange situation when testing random reads. The background to this test was that we inserted 10,000 rows with simple row keys. The number of columns in each row varies between about 5 columns and 40 columns (all

Re: Very slow reads - connected to TBufferedTransport buffer sizes

Yes this is the issue. Thanks. Dave On Tuesday, August 3, 2010, Jonathan Ellis jbel...@gmail.com wrote: Sounds like https://issues.apache.org/jira/browse/THRIFT-638, where Arya Goudarzi posted a patch. On Tue, Aug 3, 2010 at 5:18 AM, Dave Gardner dave.gard...@imagini.net wrote: Hi all I'm

Re: Cassandra vs MongoDB

There are quite a few differences. Ultimately it depends on your use case! For example Mongo has a limit on the maximum document size of 4MB, whereas with Cassandra you are not really limited to the volume of data/columns per-row (I think there maybe a limit of 2GB perhaps; basically none)