Twitter growth prompts switch from MySQL to 'NoSQL' database
Hopes open source technology can further boost improving Twitter uptime record
Computerworld - Ryan King, an engineer at Twitter, today told the blog MyNoSQL that the social networking company plans to move from MySQL to the Cassandra database for what he called its resilience, scalability and large community of open-source developers.
"We have a lot of data, the growth factor in that data is huge and the rate of growth is accelerating," King said in the interview posted on MyNoSQL.
San Francisco-based Twitter currently uses a cluster of MySQL servers with a memcached caching system that "is quickly becoming prohibitively costly (in terms of manpower) to operate. We need a system that can grow in a more automated fashion and be highly available," King told MyNoSQL.
The number of daily tweets has grown more than twenty-fold in the past year, from about two million a day in January, 2009 to nearly 50 million a day last month.
Twitter has nevertheless improved its uptime significantly in the last 12 months. The site was up 99.72% (down 23 hours, 45 minutes) in the last 12 months, according to Web monitoring firm, Pingdom. In 2008, according to Pingdom, Twitter was down for 84 hours, worst of 15 major social networking sites.
Twitter hopes that deploying the Apache Software Foundation's Cassandra database will improve that record further.
First developed by Facebook to augment its MySQL installation, Cassandra is a lean Java-based data store, that shucks the overhead of conventional relational databases. The technology is similar to that offered in other emerging NoSQL databases like MapReduce and Hadoop,
For skilled programmers, the so-called NoSQL databases can boost performance and scalability, which has made them attractive to the consumer Web world.
Cisco Systems Inc., hosting provider Rackspace and other firms also use Cassandra. The largest Cassandra instance in production runs 100TB of data using 150 servers, according to the project's web site.
The interview was cited in a tweet from King, who has 297,334 Twitter followers.
In the blog intervirew, King said that Twitter looked at a number of options for upgrading its system, including re-architecting MySQL so that it runs better in a cluster (called 'sharding'), and the offerings of several Cassandra NoSQL rivals such as HBase, Voldemort, MongoDB, MemCacheDB, Redis and HyperTable.
King said that test found that Cassandra was more scalable, reliable and easier to manage than the alternatives.
Twitter is "currently moving our largest (and most painful to maintain) table -- the statuses table, which contains all tweets and retweets" to Cassandra, he said. "After this we'll start putting some new projects on Cassandra and migrating other tables."
To minimize downtime during the migration, Twitter plans to implement new features by running them in Cassandra alongside MySQL in case any bugs crop up. Once its determined there are no bugs, Twitter will back up MySQL data and then export it to Cassandra in a process that would take about a week, he said.
Only after more testing, will it turn Cassandra on for production and shut down MySQL.
"Our process for rolling out new major infrastructure can be summed up as 'integrate first, then iterate,' King said.
Eric Lai covers Windows and Linux, desktop applications, databases and business intelligence for Computerworld. Follow Eric on Twitter at @ericylai, send e-mail to firstname.lastname@example.org or subscribe to Eric's RSS feed .
Read more about Databases in Computerworld's Databases Topic Center.
- Software Asset Management: Ensuring Today's Assets Today's trends like BYOD and SaaS are new and exciting in terms of how they will help make our jobs more productive but...
- Trends Shaping Software Management: 2014 Most IT executives recognize the relationship between mobile computing and worker productivity, and have long issued notebook computers and other mobile devices to...
- Software Asset Management: Pay Attention or Pay Up There is a wide range of options for managing software assets, from in-house solutions to the cloud to managed services providers. Read this...
- 13 Reasons to Move to Adobe Creative Cloud One of the big advantages Adobe Creative Cloud for teams offers over Adobe Creative Suite 6 perpetual software is the ability to continually...
- It's not too late...Get Your Mobile Questions Answered Live! How can IT provide seamless and secure mobile communications and collaboration for all? Join this live Webcast as IDG asks an expert panel...
- Capturing Data in Motion: Delivering Real-Time Insight from Data Streams This webcast will help organizations of all types and sizes learn about a technology and business strategy for tapping into the wealth of... All Business Intelligence/Analytics White Papers | Webcasts
Our new bimonthly Internet of Things newsletter helps you keep pace with the rapidly evolving technologies, trends and developments related to the IoT. Subscribe now and stay up to date!