Erlang is a general-purpose programming language and runtime environment with built-in support for concurrency, distribution and fault tolerance. It was developed in 1986 at Ericsson for developing telecommunications systems. Some key features of Erlang include simplicity, managing concurrency and failure through lightweight processes, and a mature community. While setup can be complex and it lacks static types, Erlang excels at handling concurrency robustly. Major companies like WhatsApp use Erlang for its reliability in large distributed systems.

1. ERLANG
Operating Systems
PST22211- 2020
Dilshan Chathuranga
Hashani Sandunika
Ishan Suranga
Maduka Shashikani
Minoli Sachinthana
Osuri Dishmini
Pinindu Chethiya
Sandunika Hashani
Thisaru Dhanushika
Yalini Pushpakanthan
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2. History01
Facts02
Syntax03
Uses04
Agenda
Style
05 Pros & Cons
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3. In a nutshell, what is Erlang?
Erlang is a general-purpose programming language and runtime
environment. Erlang has built-in support for concurrency,
distribution and fault tolerance. Erlang is used in several large
telecommunication systems from Ericsson. Erlang is available
as open source from http://www.erlang.org.
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4. The Founder
Along with Robert Virding and Mike
Williams in 1986, Armstrong develo
ped Erlang, which was released as o
pen source in 1998.
Joseph Leslie Armstrong (27
December 1950 – 20 April 2019)
was a computer scientist working
in the area of fault – tolerant
distributed systems. He is best
known as one of the co-designers
of the Erlang programming
language.
Joe
Armstrong
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5. What is it ??
-----------------------------------------------------
• Erlang was designed with the aim of
improving the development of
telephony applications.
------------------------------------------------------
• The initial version of Erlang was
implemented in Prolog and was
influenced by the programming
language PLEX used in earlier
Ericsson exchanges.
------------------------------------------------------
• In 1992, work began on
the BEAM virtual machine (VM) which
compiles Erlang to C using a mix of
natively compiled code and threaded
code to strike a balance between
performance and disk space.
------------------------------------------------------
• According to Armstrong, the language
went from lab product to real
applications following the collapse of
the next-generation AXE
telephone named AXE-N in 1995.
The name Erlang,
attributed to Bjarne
Däcker, has been
presumed by those
working on the
telephony switches
(for whom the
language was
designed) to be a
reference to Danish
mathematician and
engineer Agner
Krarup Erlang and
a syllabic
abbreviation of
"Ericsson
Language".
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6. • As a result, Erlang was chosen for the next
Asynchronous transfer mode (ATM)
exchange AXD.
• In 1998 Ericsson announced the AXD301
switch, containing over a million lines of
Erlang and reported to achieve a high
availability of nine “9” s.
• Shortly thereafter, Ericsson Radio Systems
banned the in-house use of Erlang for new
products, citing a preference for non-
proprietary languages. The ban caused
Armstrong and others to leave Ericsson.
• The implementation was open-sourced at the
end of the year. Ericsson eventually lifted the
ban and re-hired Armstrong in 2004.
• In 2006, native symmetric multiprocessing
support was added to the runtime system and
VM.
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7. Timeline of Erlang
Ericsson CS
Lab formed
1984 1987 1991 1993 1994 1996
First fast
Implementation
First Product
Early Erlang
Prototype
Distributed
Erlang
Open telecom
platform
1998
Become open
Source
Future
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8. #Facts
Contents Title
• In 2014, Ericsson reported Erlang was being used in
• its support nodes, and in GPRS ,3G and LTE mobile
networks worldwide and also by Nortel and T-Mobile.
• As Tim Bray, director of Web Technologies at Sun
Microsystems, expressed in his keynote at O’Reilly Open
Source Convention (OSCON) in July 2008:
• If somebody came to me and wanted to pay me a lot of money
to build a large scale message handling system that really had
to be up all the time, could never afford to go down for years at
a time, I would unhesitatingly choose Erlang to build it in.
• Erlang is the programming language used to code Whatsapp.
Contents Title Contents Title
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9. Erlang Features
• Concurrency
• Fault tolerance
• Soft – Real time
• Distribution
• Hot code loading
• External Interfaces
• Platform Independent
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10. Data Types
• Numbers: Integers and floats
• Atoms – similar to constants
(true and false are atoms)
• Funs – anonymous functions
• Sum = fun(X,Y) -> X+Y end.
• Sum(5,5)
• Tuples – Fixed amount of data.
Any item can be accessed in
constant time
• Lists – Group of data types;
varying amount. First item can
be accessed in constant time,
while other elements can be
accessed in O(n) time.
• Records – similar to structs in c
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11. Syntax
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12. Syntax
Hello World
You can simply impress your audience and add
a unique zing and appeal to your Presentations.
Content
Here
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13. Recursive
Functions
-module(recursive).
-export([fact/1, qsort/1]).
fact(1) -> 1;
fact(N) -> N * fact(N - 1).
qsort([]) -> [];
qsort([H | T]) ->
qsort([X || X <- T, X < H])
++ [H] ++
qsort([X || X <- T, X >= H]).
• Recursive.erl
• Compile/Run
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14. Guarded Commands
• Compare.erl
-module(guarded).
-export([gt/2]).
greaterThan(N, M) ->
if N > M -> true;
N < M -> false;
true -> equal
end.
while(N) when N == 5 ->
io:fwrite("~n~B ",[N]), while(N-
1);
while(N) when N > 0 ->
io:fwrite("~B ",[N]), while(N-1);
while(_) when true ->
done.
• Compile/Run
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15. Who use Erlang
146 companies reportedly use Erlang in their tech stacks, including WhatsApp, Heroku, and thoughtbot.
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16. Erlang Integrations
Rollbar, Google Code Prettify, Airbrake, Tile38, and Leptus are some of the popular tools that
integrate with Erlang. Here's a list of all 7 tools that integrate with Erlang.
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17. Pros
&
Cons
Pros
• Simplicity
this is one of the most valuable characteristics of a language.it has a very
small set of syntactic primitives that can use. Even the concurrent aspect of
the language is done using just plain functions (with the exception of
the receive primitive).
Erlang's simplicity also makes it very understandable and fun to work
with.
• Managing Concurrency & Failure
Erlang concurrent programs can be built, scaled and distributed with
ease. Once you have the deployment and integration set up, scaling
Erlang nodes and spawning new Erlang processes on different
machines becomes easy. Erlang standard library provides easy-to-
use functions for this very purpose, so reaching parallelism is not only
cheap in terms of implementation but also elegant.
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18. • When it comes to program failures Erlang also has your back. When spawning new
processes you are guaranteed to be notified about it to all the monitors and links
that were established. This allows to re-spawn any failed process automatically,
which is already part of the OTP standard library and the default way for structuring
Erlang applications.
Mature community
• One of the most important aspects to consider when trying to predict a technology's
future is to check the what kind of community that technology is being supported
and used by. We've all seen good technologies that end up being destroyed with
useless and buggy features; this is usually what a toxic community does.
• Erlang's community is small, mature and simplicity-driven, which protects it from
being destroyed. This is why Erlang benefits and robustness has lasted this long.
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19. Pros
&
Cons
Cons
Setup
Setting up, provisioning and deploying Erlang applications can be hard
to understand and cumbersome. This is due to many reasons, one of the
most important ones being the lack of a proper and unique package
manager.
Also, the hot-reloading feature that Erlang provides by default is no
longer applicable is nowadays containerization of applications. Instead of
having to upload the new code and triggering a hot-reload, you would
just start up an new container and stop the one that's currently running.
The Docker-way of doing things differs a bit from the Erlang-way, so in
some cases, you may have to apply some hack-ish behavior for
deployments.
Types
Erlang is a dynamically-typed language, meaning that during the
compilation phase you won't get any type errors. Erlang's robustness
and failure handling makes errors during runtime a lot less costly.
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20. Conclusion
All-in-all, Erlang does an almost-perfect job at
handling concurrency and the complexity involved
when dealing with it, including error handling,
concurrency guarantees and architectures
robustness. Even though it lacks some very useful
features used by many programming languages like
a proper package manager and a static type-checker,
it does not obfuscate its benefits. Erlang might not
be the right tool for every project, but it's definitely
very practical and safe working with it which makes
it worth considering it.
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21. THANK YOU
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Any Questions???