Feeds

Google blames Gfail on 'availability' upgrade

100-minute outage. Won't happen again. Really

  • alert
  • submit to reddit

Build a business case: developing custom apps

Calling Tuesday's one-hour-and-forty-minute Gmail outage a "Big Deal," Google has pinned the breakdown on some recent changes to the request routers that direct queries to the service's web servers.

Ironically, at least some of the changes were meant to improve Gmail's ability to stay online. But Google underestimated the load these changes would place on the routers when it took a relatively small number of servers offline for upgrades.

The company says it will spend the next few weeks correcting the problem, and it continues to boast that despite several conspicuous outages in recent months, Gmail "remains more than 99.9% available to all users."

In a blog post that surfaced on Tuesday night, Google said Tuesday's outage lasted for about 100 minutes. And though it didn't say what percentage of users were affected, it call the breakdown "a Big Deal, and we're treating it as such." Judging from reports from Reg and the Tweetbook set, the outage was worldwide, and Google indicated in an earlier post to its Google Apps Status dashboard that a "majority" of users were affected.

This morning Pacific time, Google took "a small fraction" of its Gmail servers offline for routine upgrades, and this put an unexpected load on its request routers. "We had slightly underestimated the load which some recent changes (ironically, some designed to improve service availability) placed on the request routers — servers which direct web queries to the appropriate Gmail server for response," reads the post form Ben Treynor, the Google vp of engineering who calls himself Site Reliability Czar.

"At about 12:30 pm Pacific a few of the request routers became overloaded and in effect told the rest of the system 'stop sending us traffic, we're too slow!' This transferred the load onto the remaining request routers, causing a few more of them to also become overloaded, and within minutes nearly all of the request routers were overloaded."

This meant that who knows how many people were unable to access Gmail via the web - though the service was still available via POP and IMAP. Boasting that the Gmail engineering team was alerted to the problem within seconds - "we take monitoring very seriously" - the company solved the issue by bringing more request routers online. Service was restored at about 2:10pm Pacific.

Google says it will now increase its request router capacity well beyond peak demand - and make some additional tweaks to its infrastructure. "For example," Treynor says, "we have concluded that request routers don't have sufficient failure isolation (i.e. if there's a problem in one datacenter, it shouldn't affect servers in another datacenter) and do not degrade gracefully (e.g. if many request routers are overloaded simultaneously, they all should just get slower instead of refusing to accept traffic and shifting their load).

"We'll be hard at work over the next few weeks implementing these and other Gmail reliability improvements."

According to Treynor, Google has turned its "full attention to helping ensure this kind of event doesn't happen again." ®

Next gen security for virtualised datacentres

More from The Register

next story
Kate Bush: Don't make me HAVE CONTACT with your iPHONE
Can't face sea of wobbling fondle implements. What happened to lighters, eh?
Video of US journalist 'beheading' pulled from social media
Yanked footage featured British-accented attacker and US journo James Foley
Caught red-handed: UK cops, PCSOs, specials behaving badly… on social media
No Mr Fuzz, don't ask a crime victim to be your pal on Facebook
Ballmer leaves Microsoft board to spend more time with his b-balls
From Clippy to Clippers: Hi, I see you're running an NBA team now ...
Online tat bazaar eBay coughs to YET ANOTHER outage
Web-based flea market struck dumb by size and scale of fail
Amazon takes swipe at PayPal, Square with card reader for mobes
Etailer plans to undercut rivals with low transaction fee offer
Assange™: Hey world, I'M STILL HERE, ignore that Snowden guy
Press conference: ME ME ME ME ME ME ME (cont'd pg 94)
Call of Duty daddy considers launching own movie studio
Activision Blizzard might like quality control of a CoD film
US regulators OK sale of IBM's x86 server biz to Lenovo
Now all that remains is for gov't offices to ban the boxes
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.