Building high-availability solutions with NoSQL - Making Sense of NoSQL - page 190

distributed data stores like key-value stores. Key-value stores don't use joins; they lever-
age consistent hashing; and they have strong scale-out properties. Simplicity of design
frequently promotes high availability.
With all the architectural advantages of NoSQL for creating cost-effective, high-
availability databases, there are drawbacks as well. The principal drawback is that
NoSQL systems are relatively new and may contain bugs that become apparent in rare
circumstances or unusual configurations. The NoSQL community is full of stories
where high-visibility web startups experienced unexpected downtimes using new ver-
sions of NoSQL software without adequate training of their staff and enough time and
budget to do load and stress testing.
Load and stress testing take time and resources. To be successful, your project may
need the people with the right training and experience using the same tools and con-
figuration you have. With NoSQL still newer than traditional RDBMS s, the training
budgets for your staff need to be adjusted accordingly.
In our next chapter, you'll see how using NoSQL systems will help you be agile
with respect to developing software applications to solve your business problems.

8.7 Further reading

 “About Data Partitioning in Cassandra.” DataStax. http://mng.bz/TI33 .
 “Amazon DynamoDB.” Amazon Web Services. http://aws.amazon.com/
dynamodb .
 “Amazon DynamoDB: Provisioned Throughput.” Amazon Web Services.
http://mng.bz/492J .
 “Amazon S3 Service Level Agreement.” Amazon Web Services.
http://aws.amazon.com/s3-sla/ .
 “Amazon S3—The First Trillion Objects.” Amazon Web Services Blog.
http://mng.bz/r1Ae .
 Apache Cassandra. http://cassandra.apache.org .
 Apache JMeter. http://jmeter.apache.org/ .
 Brodkin, Jon. “Amazon bests Microsoft, all other contenders in cloud storage test.”
Ars Technica. December 2011. http://mng.bz/ItNZ .
 “Data Protection.” Amazon Web Services. http://mng.bz/15yb .
 DeCandia, Giuseppe, et al. “Dynamo: Amazon's Highly Available Key-Value Store.”
Amazon.com. 2007. http://mng.bz/YY5A .
 Hale, Coda. “You Can't Sacrifice Partition Tolerance.” October 2010.
http://mng.bz/9i3I .
 “High Availability.” Neo4j. http://mng.bz/9661 .
 “High-availability cluster.” Wikipedia. http://mng.bz/SHs5 .
 “In Search of Five 9s: Calculating Availability of Complex Systems.” edgeblog. Octo-
ber 2007. http://mng.bz/3P2e .