Feeds

Facebook reveals 700TB of tiered RAM and flash power Graph Search

The Social NetworkTM lifts skirts, shows glimpses of MySQL, Hadoop and Unicorn

High performance access to file storage

Facebook has revealed a little more detail about how it built Graph Search, the feature it took live a couple of weeks back to enable better searching of the billion posts it now collects each day.

The reveal came in a blog post, as is the fashion at this time, that explains building better search across posts is hard because Facebook has “70 different kinds of data we sort and index on, many of them specific to certain types of posts.”

That's all managed by MySQL, which passes data to a HBase cluster before Hadoop gets to work. At this point “Unicorn”, Facebook's name for the tech powering its search engine, gets involved and the result is a colossal index with a very substantial cache that the company tries to treat as gently as possible.

Keeping the cache happy is not a trivial task, so the company has devised the following tiering regime:

“However, storing more than 700 terabytes in RAM imposes a large amount of overhead, as it involves maintaining an index that is spread across many racks of machines. The performance cost of having these machines coordinate with each other drove the Unicorn team to look into new solutions for serving the posts index. The solution we decided on involves storing the majority of the index on solid-state flash memory. We managed to preserve performance by carefully separating out the most frequently accessed data structures and placing those in RAM.”

RAM as tier zero and flash as tier one are suggested as the recipe for fast access to data by just about the whole storage and big data industries, so Facebook's infrastructure will please many a sales and marketing person and probably make its way into lots of slideware before too much time passes.

Perhaps a little more interesting is the post's statement that Graph Search was built “in the past year by a few dozen engineers”. Plenty of lesser projects take more time and more people, suggesting the most interesting thing IT pros and their managers can learn from Graph Search might be how the project was managed and the hardware designed and implemented, rather than the configurations chosen. ®

High performance access to file storage

More from The Register

next story
Seagate brings out 6TB HDD, did not need NO STEENKIN' SHINGLES
Or helium filling either, according to reports
European Court of Justice rips up Data Retention Directive
Rules 'interfering' measure to be 'invalid'
Dropbox defends fantastically badly timed Condoleezza Rice appointment
'Nothing is going to change with Dr. Rice's appointment,' file sharer promises
Cisco reps flog Whiptail's Invicta arrays against EMC and Pure
Storage reseller report reveals who's selling what
Bored with trading oil and gold? Why not flog some CLOUD servers?
Chicago Mercantile Exchange plans cloud spot exchange
Just what could be inside Dropbox's new 'Home For Life'?
Biz apps, messaging, photos, email, more storage – sorry, did you think there would be cake?
IT bods: How long does it take YOU to train up on new tech?
I'll leave my arrays to do the hard work, if you don't mind
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.