In the 4th week of the DataStax’s Cassandra NYC 2011 video series, we have Joe Stein from Medialets talking about the architecture

Before diving into the video here are some interesting data points:

• Medialets serves rich media ads
  • they handle 3-4TB of daily data
  • microsecond-level response times
• Cassandra is used for time series and aggregate metrics
• all MapReduce jobs written in Python. This reminded me of the recent post about the performance impact of operations in Hadoop Map phase

• Medialets architecture:

  

• Major components of the Medialets’s architecture:

  • Kafka
  • MySQL
  • Cassandra: 6 node cluster, 100k requests, single DC
  • Hadoop
  • ZooKeeper: coordinates all the services on the platform
    
• some of the data in MySQL is replicated in Cassandra (and coordinated with ZooKeeper)
• data is fed back to MySQL
• Kafka for collecting analytics data:
  • aggregates go into Cassandra
  • events in Hadoop
• GROUP BY with Cassandra
• for real-time systems aggregations must be done upfront
• the way data is segmented is critical
• aggregation leads to data explosion

For today’s Powered by Cassandra video from the Cassandra NYC 2011 event organized by DataStax, I chose Chris Burroughs’s presentation about Clearspring’s usage of Cassandra. Just in case you wonder what Clearspring is doing, the sharing buttons you see here on myNoSQL are powered by AddThis product from Clearspring.

While today was supposed to be a new educational video from the Cassandra NYC 2011 video series, I thought that learning from the lessons of operating Cassandra at Outbrain to serve over 30 billion impressions monthly will be quite educational.

To keep with last week’s model—an educational video about Cassandra, followed by a Cassandra case study—today’s video in the Cassandra NYC 2011 video series from DataStax, is Ilya Maykov describe how Cassandra is used at Ooyala for computing multi-dimensional video analytics reports for 100M+ monthly unique users in near-real-time.

Continuing the Cassandra NYC 2011 video series, made available by the folks from DataStax, this week we have Matthew F. Dennis which covers a couple of different Cassandra data modeling use cases.

To alternate a bit after yesterday’s educational CQL: SQL for Cassandra in the Cassandra NYC 2011 video series from DataStax, today’s video is Drew Robb covering Cassandra usage at SocialFlow for capturing real-time data from Twitter and Bit.ly.

The fine folks from DataStax have made available the presentations from their Cassandra NYC 2011 event.

The first video to post here is Eric Evans’s presentation on Cassandra Query Language.