you call that micro, mr. docker? how osv and unikernels help micro-services stay micro

YOU CALL THAT MICRO, MR. DOCKER? HOW OSV AND UNIKERNELS HELP MICRO-SERVICES STAY MICRO

Roman Shaposhnik @rhatr, Pivotal Inc.

It is 2015 and everybody loves PaaS

Cloud Foundry

No, but seriously?

myApp $ cf push …

service #N

service #1

…

service #Z

service #M

…

Forget OOP, it is 0xCOP (12factor.net) •  Codebase •  Dependencies •  Config •  Backing services •  Build, deploy, run •  Stateless processes

•  Port binding •  Concurrency •  Disposability •  Dev == prod •  Logs == streams •  Admin processes

What about stateful?

HDFS

Zookeeper

HBase region server

… I am alive Who Am I? What do I do?

HBase region server

And when it fails?

HDFS

Zookeeper

HBase region server

… Node died You, pitch in! Aye, aye captain

μservice-‐based deployment

HDFS

Zookeeper

HBase region server

… I am alive Who Am I? What do I do?

HBase region server

Lets zoom in

…

service #N

service #1

Anatomy of a μservice

Hardware

“Stuff”

[Java] Virtual Machine

μservice code

How are we doing it today?

Hardware

pkg1

[Java] Virtual Machine

μservice code

pkgN …………. “OS” Linux kernel

Puppet, Chef

Huge VM image

Is there a beber way?

vHardware

Hardware

[Java] Virtual Machine libFS, libC, libJVM

μservice code

Applicacon-‐specific stacc linking

Tiny VM image AKA unikernel

Hardware-‐assisted virtualizacon

What the heck is a FOOkernel? •  What OS design courses have taught us? – microkernels vs. monolithic kernels

•  What did they lef behind? – exokernels, nano

•  What they should’ve taught us instead: – unikernels, anykernels

Unikernels •  “Unikernels: library operacng systems for the cloud” came out in 2013

•  A “library” operacng system •  A kernel that can only support one process

Anykernels •  Programming discipline for kernel code reuse •  “The Design and Implementacon of the Anykernel and Rump Kernels” by A. Kantee

•  Capabilices – NetBSD filesystems as Linux processes – User-‐space TCP/IP stack

•  Building blocks for… any kernels

OSv from Cloudius Systems •  A unikernel for “POSIX” and memory managed planorms (JVM, Go, Lua)

•  Anykernel’ish –  E.g. ZFS

•  Runs on top of KVM, Xen, VirtualBox, VMWare •  Looks like an app to the host OS •  Small, fast and easy to manage at scale

OSv manifesto •  Run exiscng Linux applicacons •  Run exiscng Linux applicacons faster •  Make boot cme ~= exec cme •  Explore APIs beyond POSIX •  Leverage memory managed planorms (JVM, Go) •  Stay open

What’s inside?

single address space in “kernel mode”

“kernel threads” “user threads”

disk ZFS virco C++ kernel code

dynamic linker

libjvm.so ifconfig.so

TCP/IP

iface

Anything it can’t do? •  A 100% replacement for a Linux kernel – No fork()ing

•  No process isolacon •  The least amount of device drivers ever

Virtualizacon vs. performance •  Network-‐intensive apps: –  unmodified: 25% gain in throughput 47% decrease in latency

–  non-‐POSIX APIs use for Memcached: 290% increase in performance

•  Compute-‐intensive apps: –  YMMV

Van Jacabson’s net channels socket

TCP

IP

iface

socket

TCP

IP

iface

lock

lock

lock

Tradiconal TCP/IP stack

app thread kernel (IRQ)

send/recv

socket

TCP

IP

iface

channel

classifier

iface

lock

OSv TCP/IP stack

app thread kernel (IRQ)

send/recv

Memory management in UNIX

OS Memory

Process Memory

JVM Heap

Process Memory

JVM Heap

Memory management in OSv

OS Memory

Process Memory

JVM Heap

JVM balooning (no more -‐Xmx)

JVM Heap

OS object

Turbo charging JVM GC

object 1 object 2

Turbo charging JVM GC

object 1 object 2

CPU MMU assisted tracking table

But what about Docker?

Jailed FS, net, etc.

Hardware

[Java] Virtual Machine libFS, libC, libJVM

μservice code

Applicacon-‐specific stacc linking

Docker image

Common, shared kernel

Docker != LXC •  $ docker run roman/PetClinic •  Socially-‐driven image sharing

Ubuntu 14.04

Canonical

Tomcat

Pivotal

Go

Google

PetClinic

Roman

PetClinic

service #N

service #1 $ docker run

Why should it work this cme? •  Unikernels/exokernels back in ’90 •  JVM-‐on-‐bare-‐metal (Azul, BEA, etc.) back in ‘00 •  Things they didn’t have back then – HW-‐assisted virtualizacon (KVM, XEN, etc.) –  Elascc infrastructure oriented architectures –  Cloud Foundry

No, really we need PaaS

Elascc, next generacon datacenter •  Commodity, rack-‐provisioned Hardware •  Commodity, JeOS to get to Docker++ – CoreOS, SmartOS

•  Docker++ as a common backed – Osv

•  Cloud Foundry to rule them all

Finally killing DevOps •  Ops (IT) maintains the bare OS •  Devs maintain the μservices •  PaaS maps μservices to images and orchestrates

Guinea pigs so far •  Cloudius – Memcached – Apache Cassandra – Redis

•  Pivotal – Apache Geode (incubacng)

Apache Geode (incubacng) •  Formerly known as Gemfire •  Distributed, fully consistent, in-‐memory database/cache system with transaccons

•  Key-‐value client API •  Java based •  Peer-‐to-‐peer distributed system

Quescons?

By @cloud_opinion Imagine no planorms I wonder if you can No need for PAAS or IAAS A brotherhood of bare metal Imagine there is no VM It's easy if you try No host below us Above us only apps

you call that micro, mr. docker? how osv and unikernels help micro-services stay micro

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