Urs Hölzle Profile picture
SVP Engineering at Google, working on the infrastructure powering Google Cloud and Google. Opinions are my own and are worth exactly what you pay for them.
Jul 13, 2022 10 tweets 3 min read
In this next episode of "Tales from the trenches of infrastructure", learn about the power of lasers...how did this piece of fiber get burnt to a crisp? (Hint: lasers!)

A thread.⬇️ We use two types of optical amplifiers in our network. The workhorse is what's known as an Erbium Doped Fiber Amplifier.

fiberlabs.com/glossary/erbiu…
Dec 17, 2021 6 tweets 1 min read
Here's another story from the trenches of the internet. Last month, a fire in a rural area of South Carolina damaged one of the fiber links that connect Google datacenters (picture below). 100Tbps of capacity lost and restored in 12 hours!🧵 Image What you see is a "splice box" where the fiber briefly come to the surface, for example, to connect to a different fiber route. Often these are underground, too, but not here.
Sep 26, 2021 13 tweets 3 min read
A trip down memory lane...exactly 23 years ago Google signed its first datacenter contract.  Let's walk through the lease in a thread. First, the copy you see here was sent by a "fax machine" which was something people used back then. Image The data center provider was Exodus, a now-defunct company that was a leading provider at the time and had a market cap of tens of billions of dollars at the height of the dotcom bubble.  The facility was located at 2251 Lawson Lane in Santa Clara (since torn down).
Oct 7, 2020 5 tweets 1 min read
Wednesday at 7am PDT, the Supreme Court of the US is hearing a landmark case, Google v. Oracle. Google's side is supported by fifteen amicus briefs filed by orgs as diverse as Microsoft, Red Hat, Mozilla, 78 computer scientists, and the American Antitrust Institute. Why is this so important? If Oracle won, APIs would be copyrighted. Anyone who knows software understands how disastrous that would be.
Jun 15, 2020 12 tweets 3 min read
1/ Looks like a piece of Google Cloud history found its way to @donttrythis of Myth Busters fame. The video does a great job showcasing it, except Adam should have turned off the lights in the cave ;-) But let me add a few bits about its history.

2/ Back in 2008 or 2009 I came across a flashlight that was beautifully made and super bright, but not quite safe. It got so hot after a few minutes that you could get burns, and more importantly put the lithium ion batteries in jeopardy. But it was insanely bright.
May 21, 2020 4 tweets 1 min read
Ok here's a new one: did you know that cows can cause network outages? Don't laugh, it happened to us.

The beginning of the story: recently, we noticed frequent short outages ("flaps") on a multi-terabit fiber path through Oregon. 1/ This link is an aerial fiber link (fiber is strung along the path of a high-voltage power line). Such links have lower reliability because storms, trees, ice, and the occasional hunter can damage them. 2/