Andrew Pliszka gives a lightning talk on Erlang

1. Prolog
to
Erlang
First
version
of
Erlang
was
wri2en
in
Prolog

2. Examples

3. hello_mod.erl
1. -­‐module(hello_mod).
2. -­‐export([say_hello/0]).
3. say_hello()
-­‐>
4.
io:format("Hello~n",
[]).

4. hello_mod:say_hello().
1. $
erl
2. Erlang
R14B04
(erts-­‐5.8.5)
[source]
[64-­‐bit]
[smp:4:4]
[rq:4]
[async-­‐threads:0]
[hipe]
[kernel-­‐poll:false]
3. Eshell
V5.8.5
(abort
with
^G)
4. 1>
c(hello_mod).
5. {ok,hello_mod}
6. 2>
hello_mod:say_hello().
7. Hello
8. ok
9. 3>

5. fact_mod.erl
1. -­‐module(fact_mod).
2. -­‐export([fact/1]).
3. fact(0)
-­‐>
1;
4. fact(N)
-­‐>
N
*
fact(N
-­‐
1).

6. fact_mod:fact(4).
1. $
erl
2. Erlang
R14B04
(erts-­‐5.8.5)
[source]
[64-­‐bit]
[smp:4:4]
[rq:4]
[async-­‐threads:0]
[hipe]
[kernel-­‐poll:false]
3. Eshell
V5.8.5
(abort
with
^G)
4. 1>
c(fact_mod).
5. {ok,fact_mod}
6. 2>
fact_mod:fact(4).
7. 24
8. 3>

7. qsort_mod.erl
1. -­‐module(qsort_mod).
2. -­‐export([qsort/1]).
3. qsort([])
-­‐>
4.
[];
5. qsort([H
|
T])
-­‐>
6.
qsort([
X
||
X
<-­‐
T,
X
<
H
])
++
7.
[H]
++
8.
qsort([
X
||
X
<-­‐
T,
X
>=
H
]).

8. qsort_mod:qsort([3,
2,
1,
6,
4,
5]).
1. $
erl
2. Erlang
R14B04
(erts-­‐5.8.5)
[source]
[64-­‐bit]
[smp:4:4]
[rq:4]
[async-­‐threads:0]
[hipe]
[kernel-­‐poll:false]
3. Eshell
V5.8.5
(abort
with
^G)
4. 1>
c(qsort_mod).
5. {ok,qsort_mod}
6. 2>
qsort:qsort([3,
2,
1,
6,
4,
5]).
7. [1,2,3,4,5,6]
8. 3>

9. History
§ 1986
-­‐
Joe
Armstong
(Ericsson)
§ Prolog
§ 1988
-­‐
Ericsson
AXD301
ATM
telco
switch
§ 1
million
lines
of
Erlang
§ 99.9999999
§ 1995
-­‐
Open
Telecom
Plalorm
§ 1998
-­‐
Open
source
§ 2011
-­‐
Release
14B03

10. What s
Erlang?

11. Programming
Language
§ General-­‐purpose
§ Funcponal
§ Like
LISP,
Haskell
§ Garbage-­‐collected
§ Dynamic
typing
§ Single
assignment
§ Erlang
runpme
system
§ STDLIB

12. Features
§ Massive
concurrency
and
message
passing
§ Actor
model
§ Sos-­‐real-­‐pme
§ Thousands
of
processes
under
single
VM
§ Short
GC
pauses
§ Distributed
§ Erlang
nodes
§ Fault-­‐tolerant
§ 99.9999999%
§ Powerful
error
handling
§ Supervisors
§ Recovery
from
errors
§ Non-­‐stop
systems
§ Hot
code
swapping
in
producpon

13. Data
types
§ Atoms
§ open,
close,
`empty
§ Integers
§ Floats
§ Tuples
§ {price,
12.34}
§ Lists
§ [1,
2,
3,
4]
§ PIDs

14. Control
Structures
§ Pa2ern
matching
§ Guards
§ Higher
order
funcpons
§ List
comprehension

15. Actors:Message
Passing
§ Send
message
(client
process)
§ ServerProcessId
!
Message.
§ Receiving
a
message
(server
process)
§ receive
pa2ern2
-­‐>
…;
pa2ern2
-­‐>
…
end.

16. Erlang
VM
§ Thousands
of
processes
under
single
VM
§ Lightweight
processes
§ Garbage
collecpon
per
process
§ BEAM
files
§ Napve
code
compiler

17. Anywhere
§ OS
/
Hardware
independent
§ UNIX/Linux
§ Windows
§ Mac
§ Embedded
§ Android

18. Open
Telecom
Plalorm
OTP

19. OTP
Design
Principles
§ Supervision
trees
§ Supervisors
§ Workers
§ Behaviours
§ gen_server
§ The
server
in
client-­‐server
§ fsm_server
§ Finite
state
machines
§ gen_event
§ Event
handling
§ Applicapons
§ Applicapon
§ Releases

20. Web
Development

21. Web
Development
§ Web
Servers
§ Inets
§ Build-­‐in
§ Yaws
§ 80,000
concurrent
connecpons
(2002)
§ MochiWeb
§ Lightweight
HTTP
§ Web
Frameworks
§ ErlyWeb
§ MVC
for
Yaws
§ Erlang
Web
§ MVC
for
Yaws
and
Inets
§ Nitrogen
§ An
event-­‐driven
2.0
framework
(cometd)

22. Wri2en
in
Erlang
§ Apache
CouchDB
§ Document-­‐oriented
database
(replicapon)
§ RabbitMQ
§ Message-­‐oriented
middleware
§ Riak
§ NoSQL
database
(ring)
§ Ejabberd
§ XMPP
applicapon
server

23. Development
Tools
§ IDEs
§ Eclipse
§ Emacs
+
Distel
§ Vim
§ Tools
§ MOEBIUS
§ CI
Server
§ rebar
§ Build
and
packaging
tool

24. Erlang
in
Producpon
§ Ericsson
AXD301
telco
switch
§ 160
GB/s
§ 1
million
lines
of
Erlang
§ Hundreds
of
programmers
§ 99.9
999
999%
reliability
§ GPRS
§ GSM
cell
telco
network
§ Facebook
Chat
§ 800+
million
messages
/
day
§ GitHub
§ Goldman
Sachs
???
§ High-­‐frequency
trading
§ Deutsche
Bank