Interview with Eric Brewer

I'd like a real explanation for why containers are better than unikernels. Yes, unikernals are still early, and containers are convenient, because you have all of linux there... but it seems that running several linuxes on a linux machine is a bit much. One operating system plus XEN plus several applications in unikernels seems more efficient, and more exciting.

But it's the less common choice.

I am guessing convenience is more important than the better solution that would ultimately be more just as convenient and more efficient if it gets enough eyeballs?

Re: Interview with Eric Brewer

#6

Post by ticviking » Mon, May 18, 2015, 11:16 PM UTC

MCRed wrote: post #5

I'd like a real explanation for why containers are better than unikernels. Yes, unikernals are still early, and containers are convenient, because you have all of linux there... but it seems that running several linuxes on a linux machine is a bit much. One operating system plus XEN plus several applications in unikernels seems more efficient, and more exciting. But it's the less common choice. I am guessing convenie…

I strongly suspect that as time goes on we'll see that containers and uni-kernels converge.

Re: Interview with Eric Brewer

#7

Post by mark_l_watson » Mon, May 18, 2015, 11:19 PM UTC

Great Interview!

I worked as a contractor at Google in 2013 and loved their infrastructure. It was amazing to fire off a Borg job that used hundreds to thousands of servers, and the web based tools for tracking the job, fantastic logging to drill into problems, etc.

And, Borg was two generations ago!

Even though I am very happy doing what I am now, sometimes I literally wake up in the morning thinking about Google's infrastructure. I now use lesser but public services like AppEngine, Heroku, nitrous.io (like Google's web based IDE Cider, a bit) but it is not the same.

BTW, not to be negative, but while Google is a great home for someone like Eric Brewer, it is a shame that many hundreds of future students at UC Berkeley will not have him as a professeur.

Re: Interview with Eric Brewer

#8

Post by DannoHung » Mon, May 18, 2015, 11:20 PM UTC

MCRed wrote: post #5

I'd like a real explanation for why containers are better than unikernels. Yes, unikernals are still early, and containers are convenient, because you have all of linux there... but it seems that running several linuxes on a linux machine is a bit much. One operating system plus XEN plus several applications in unikernels seems more efficient, and more exciting. But it's the less common choice. I am guessing convenie…

I'm completely unfamiliar with unikernels, but I just skimmed a brief description. My first question is: Do they still incur the overhead of running against a Hypervisor like common virtual machines?

Also, possibly a clairification: Unless I'm misunderstanding what you mean by "running several linuxes on a linux machine", I believe you may be mistaken about the way containers work. Only one Linux is really running. And that is the Linux that the kernel comes from. The other stuff doesn't run unless you tell it to (so, no init, no daemons you don't specify, etcetera). Yeah the image size can be a little fat if you don't trim them down, but you can have a container nearly as small as your code is, if you statically compile. On the order of just a few bytes of overhead.

Re: Interview with Eric Brewer

#9

Post by jacquesm » Mon, May 18, 2015, 11:20 PM UTC

MCRed wrote: post #5

I'd like a real explanation for why containers are better than unikernels. Yes, unikernals are still early, and containers are convenient, because you have all of linux there... but it seems that running several linuxes on a linux machine is a bit much. One operating system plus XEN plus several applications in unikernels seems more efficient, and more exciting. But it's the less common choice. I am guessing convenie…

I'd like a real explanation for why containers and unikernels are better than regular run-of-the-mill applications running on dedicated servers. It's almost as if the wild west of the web isn't quite enough and we now need to add another explosion of layers-of-abstraction but this time on the server in order to pretend we have infinite hardware which then becomes it's own reason for existence rather than to simply run efficient software configured properly on properly utilized hardware. As if regular virtualization alone doesn't give enough headaches in trying to figure out why some subsystem does not perform.

At this rate we'll end up shipping containers as 'apps' to the clients machines with a suitable emulator at some point.

All this luxury comes at (considerable) cost and not everybody seems to be doing the math before deployment which more often than not leads to terrible efficiency.

But we're technology fans, so 'oohh! shiny!'.

Re: Interview with Eric Brewer

#10

Post by DannoHung » Mon, May 18, 2015, 11:25 PM UTC

jacquesm wrote: post #9

MCRed wrote: post #5

I'd like a real explanation for why containers are better than unikernels. Yes, unikernals are still early, and containers are convenient, because you have all of linux there... but it seems that running several linuxes on a linux machine is a bit much. One operating system plus XEN plus several applications in unikernels seems more efficient, and more exciting. But it's the less common choice. I am guessing convenie…

I'd like a real explanation for why containers and unikernels are better than regular run-of-the-mill applications running on dedicated servers. It's almost as if the wild west of the web isn't quite enough and we now need to add another explosion of layers-of-abstraction but this time on the server in order to pretend we have infinite hardware which then becomes it's own reason for existence rather than to simply ru…

Sorry, but what costs do containers incur? From my understanding, the resource overhead should be exceedingly minimal (disk space would ostensibly be the largest drawback, if you don't spend time cutting out the fat. Personally, I see this as a tooling issue since fat containers are completely orthogonal to how a container really executes). I understand some of the situation with IO isn't perfect yet, but I haven't heard anyone suggest that it cannot be corrected.