Cassandra

There’s been a few good AWS discussions recently on the Cassandra User List, and some interesting blog posts.read more

The Cassandra London meetup group has recently celebrated its six month anniversary and after a string of fantastic speakers it was left to me to follow up my talk at the first ever meetup with another talk.read more

So, I started playing with a beta of Brisk this weekend. The Datastax guys are industrious, energentic and are very open to hearing from both the Cassandra and Hadoop communities.  You should hit them in #Datastax-Brisk on Freenode IRC. I’ll … Continue reading →

Deletes in Cassandra rely on Tombstones to support the Eventual Consistency model. Tombstones are markers that can exist at different levels of the data model and let the cluster know that a delete was recored on a replica, and when it happened. ... [More] Tombstones then play a role in keeping deleted data hidden and help with freeing space used by deleted columns on disk. It’s possible to delete columns, super columns and entire rows in Cassandra. However in this post I’m going to look at the simple case of deleting a single column in a Standard Column Family.read more [Less]

div.even, div.odd { width:525px; padding:5px; } div.even { background:#E8E8E8; } Number of Nodes: More info about why you might need this calculator is available here. I wrote about it here. I attempted to write this in JavaScript, but my Brother-in-Law, Buddy, popped … Continue reading →

So, I was hoping to write a little snippet of code to embed on my blog to allow people to get the token ranges for load balancing their cluster. In Cassandra, when using the random partitioner, all keys are given … Continue reading →

Updated: I’ve added information on the new memtable_total_space_in_mb setting in version 0.8 and improved the information about memtable_throughput. Thanks for the feedback. In version 0.7 of Cassandra there are 3 configuration settings that can ... [More] trigger flushing a memtable to disk. Version 0.8 adds support for a global memtable_total_space_in_mb which may replace the previous 3 settings. First the 0.7 settings.read more [Less]

Requests that write and read data in Cassandra, like any data base, have competing characteristics that need to be balanced. This post compares the approach taken by Cassandra to traditional Relation Database Systems. When writing data the most ... [More] efficient approach to splat it somewhere on disk with the minimum of fuss. Preferably at the end of a file, or even in a new file. The write is going to take longer if the data is carefully placed in the correct ordered position in an existing file.read more [Less]

DataStax (née Riptano) is to Cassandra as Cloudera is to Hadoop (or Redhat is to Linux). Brisk is DataStax’s upcoming Cassandra/Hadoop hybrid distribution.  From thier site: DataStax’ Brisk is an enhanced open-source Apache Hadoop and Hive distribution that utilizes Apache … Continue reading →

I’m such a sad bastard. I got stuck fixing a production issue and had to miss the inagural NYC Cassandra Meetup group To attone, I figure I’d write a quickie Cassandra post. I’m in the preliminary planning stages to upgrade … Continue reading →