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Google Is 2B Lines of Code, All in One Place

wired.com

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Re: Google Is 2B Lines of Code, All in One Place

#101

Post by Touche »

devit wrote: post #22
ChuckMcM wrote: post #17

I will say that I saw and experienced many things that changed my definition of 'large' at Google, but the most amazing was the source code control / code review / build system that kept it all together. The bad news was that it allowed people to say "I've just changed the API to to support the initiative, code released after this commit will need to be updated." and have that effect hundreds of projects, but at the…

The solution to the excessive API change problem is to force whoever changes the API to fix all the consumers himself before the change is accepted. The Linux kernel generally uses this policy for internal APIs for example.

> The solution to the excessive API change problem is to force whoever changes the API to fix all the consumers himself before the change is accepted.

Having people unaware of a project's purpose making changes to its code sounds like a nightmare to me.

Re: Google Is 2B Lines of Code, All in One Place

#102

Post by dblock »

A giant repo works for Google, and works for Facebook, and Microsoft, but it's bad for the development community at large.

If you start centralizing your development you’re killing any type of collaboration with the outside world and discouraging such collaboration between your own teams.

http://code.dblock.org/2014/04/28/why-one-giant-source-contr...

Re: Google Is 2B Lines of Code, All in One Place

#103

Post by branchless »

ksk wrote: post #97

Its interesting that they compare LoC with Windows. I suppose that this article wants us to be amazed at those numbers. However, my experience with Google's products indicates a gradual decline in performance and a simultaneous gradual increase in memory bloat (Maps, Gmail, Chrome, Android). Which ironically, FWIW, hasn't been the case with Windows. I have noticed zero difference in performance going from Windows 7 t…

I'd have to disagree with this. First the baseline: windows is very slow. Second I found later versions slower. Third (and most maddening) every version of windows I've ever used has gotten slower over time (including not installing new s/w and defragmenting).

Re: Google Is 2B Lines of Code, All in One Place

#104

Post by hk__2 »

roxmon wrote: post #100
kazinator wrote: post #86

I am unable to believe that Google has 2B lines of original code written from scratch at Google. Maybe they are counting everything they use. Somewhere among those 2B lines is all the source code for Emacs, Bash, the Linux kernel, every single third-party lib used for any purpose, whether patched with Google modifications or not, every utility, and so on. Maybe this is a "Google Search two billion" rather than a conv…

Google has been around for 17 years and employees roughly 10,000+ software developers. I think it's reasonable to assume that the 2B LOC metric is accurate...

Windows has been around for 35 years and Microsoft had 61,000+ employees (ok, that’s not only software developers and they don’t work only on Windows) in 2005; and it’s only ~50M LOC. I don’t think the number of years + developpers really show something; you don’t write new code everyday.

Re: Google Is 2B Lines of Code, All in One Place

#105

Post by tuckerman »

Touche wrote: post #98
durin42 wrote: post #89

Earlier quoted context omitted.

Google has tons of services internally that talk via RPC. The monolithic repo means that it's much easier to hunt down and find people that are (say) using an outdated RPC method and help them fix their code. (Just one example of how it's useful even when things are mostly services.)

This discourages you from ever making breaking changes to an API. On the face of it that sounds good but sometimes you do have to make breaking changes. My guess is that there are many duplicate projects in the Google code base for when a breaking change is needed. This is a way to sidestep the problem.

I think sometimes it's actually the opposite. I was able to make a breaking change to an API and update all of the callers to use the new one in a single commit.

Tests would run on all the clients and, since in my workspace the server was updated simultaneously, I could be more sure it would work.

Re: Google Is 2B Lines of Code, All in One Place

#106

Post by ocdtrekkie »

branchless wrote: post #103
ksk wrote: post #97

Its interesting that they compare LoC with Windows. I suppose that this article wants us to be amazed at those numbers. However, my experience with Google's products indicates a gradual decline in performance and a simultaneous gradual increase in memory bloat (Maps, Gmail, Chrome, Android). Which ironically, FWIW, hasn't been the case with Windows. I have noticed zero difference in performance going from Windows 7 t…

I'd have to disagree with this. First the baseline: windows is very slow. Second I found later versions slower. Third (and most maddening) every version of windows I've ever used has gotten slower over time (including not installing new s/w and defragmenting).

8.1 and 10 run incredibly well even on very old hardware. I will agree a given Windows install may feel slower over time, and it makes sense to rebuild the PC occasionally, though that may, again, be less so with 8.1 and 10.

Re: Google Is 2B Lines of Code, All in One Place

#108

Post by hokkos »

kazinator wrote: post #86

I am unable to believe that Google has 2B lines of original code written from scratch at Google. Maybe they are counting everything they use. Somewhere among those 2B lines is all the source code for Emacs, Bash, the Linux kernel, every single third-party lib used for any purpose, whether patched with Google modifications or not, every utility, and so on. Maybe this is a "Google Search two billion" rather than a conv…

> Google engineers modify 15 million lines of code across 250,000 files each week > Google’s 25,000 engineers

So employees modify 120 lines / day if we imagine a linear growth in employees in 17 years to 25K coders, with 250 work day a year they employ around 6 more coders each work day, so about 55M man day, so around 6,3G LOC modified. But modified != added, so I wound't believe this is all their own lines.

Re: Google Is 2B Lines of Code, All in One Place

#109

Post by antics »

Just because people are talking about it: I work at MSFT, and the numbers Wired quotes for the lines of code in Windows are not even close to being correct. Not even in the same order of magnitude.

Their source claims that Windows XP has ~45 million lines of code. But that was 14 years ago. The last time Windows was even in the same order of magnitude as 50 million LOC was in the Windows Vista timeframe.

EDIT: And, remember: that's for _one_ product, not multiple products. So an all-flavors build of Windows churns through a _lot_ of data to get something working.

(Parenthetical: the Windows build system is correspondingly complex, too. I'll save the story for another day, but to give you an idea of how intense it is, in a typical _day_, the amount of data that gets sent over the network in the Windows build system is a single-digit _multiple_ of the entire Netflix movie catalog. Hats off to those engineers, Windows is really hard work.)

Re: Google Is 2B Lines of Code, All in One Place

#110

Post by zBard »

727374 wrote: post #67

Really? This article sounds very over simplified, but I haven't worked at google so I wouldn't know. I'm assuming if you want to change some much depended on library, there's a way to up the version number so you don't hose all your downstream users. That's the way it worked at Amazon at least. Also, I wonder why the people in the story think Google's codebase is larger than that of other tech giants, not that it rea…

Last I heard Google is still on Java 7 precisely because of this, although that might have changed. It's fun seeing the different theologies at Amazon and Google - I remember Yegge's famous platform rant, and he highlighted the Amazon versioned-library system as something which it did better than Google.
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