Recent Cassandra reading.

CQL: SQL In Cassandra

And a blog post

By Eric Evans

• Good examples of simple statements.
• Performance comparisons show CQL has 5% to 10% lower throughput and higher latency.
• List of drivers and where to get them.
• More improvements coming.

Storm Cassandra Integration

By P. Taylor Goetz

• A storm bolt to persist data to Cassandra.

Cassandra in Online Advertising: Real Time Bidding

By Edward Capriolo

• 10TB of data and growing.
• Latency requirements of less than 120ms.
• “Distributed not Duplicated” is a great phrase.
• Ed still loves the Cacti :)
• Good idea to use JMX to modify the (Cassandra) cache settings for a single node to compare against the others.
• Pay attention to how the cache hit rate varies with regard to the cache size, at some point may be better to accept a (say) 90% hit rate and give more memory to another CF.
• Tuning IO performance for peak and off-peak by modifying nodetool setcompactionlimit to improve compaction performance.
• Running night time major compactions like Urban Airship. I wonder how leveled compaction would work with the mixed workload?

Replication and the latency-consistency tradeoff

By Daniel Abadi

• A discussion about latency and consistency.
• “there’s no way to perform consistent replication across database replicas without some level of synchronous network communication.”
• Not sure I agree that in Dynamo / Cassandra (not sure about Riak) “updates generally go to the same node, and are then propagated synchronously to W other nodes (case (2)(c))”.
• I think how inconsistencies are handled during read requests is another source of latency.

Cassandra for sys admins

By Nathan Milford

• 14 nodes in two DC’s
• In productions since Cassandra version 0.4, awesome!
• A good list of things to monitor in a cluster.
• Good best practices for shutting down a node that give the fastest startup, also see.

Cassandra for LOBS

By Dan Pritchett

• Expensive SAN storage bombshell.

Expedia Hotel Price Cache

By B. Todd Burruss

• Pre-calculate, trading space for time.
• A rolling window of 2.8 billion data points.
• Test, measure, tune.

Data Modeling Examples

By Matthew Dennis

• I always check out Matthew’s data model presentations to see what the best practices are.
• “Usually better to keep a record that something happened as opposed to changing a value”.
• Good advice on time series and the XACT_LOG.

Cassandra In Production: Things We Learned

By Walt Jones

• Using Cassandra 0.7, there are a lot of improvements in Cassandra 1.0.
• 12 AWS EC2 m1.xlarge nodes with 5TB of data.
• S3 archive
• The memory footprint issues has been eliminated in Cassandra 1.0.
• Please avoid using Super Columns.
• Please use the Random Partitioner.

Data Modeling with Cassandra

By Sam Overton

• De-normalize for a brighter future.
• No SQL “Hello World” twitter example.