erlang latest version & opensource projects
TRANSCRIPT
ERLANG LATEST VERSION &
OPENSOURCE PROJECTS
HELLO!I am Akhil Agrawal
Doing Erlang development for last five yearsDoing Ejabberd development for last six months now
Started BIZense in 2008 & Digikrit in 2015
Latest Version – 18Highlights and summary of version 18 and
newer releases of Erlang1
HIGHLIGHTS & SUMMARY
Erlang Public License changed to Apache Public License v2
License Change
ssl3 & rc4 cipher default support removed to prevent poodle vulnerability, additional key exchange algorithms, other safety improvements
SSL/SSH ImprovementsPerformance improvments in timer
management, scheduler, erlang:make_ref and persistent hashmaps for large maps.
Performance/Scalability
Improvements in time functionality & management. erlang:now is deprecated, timers api changes
Extended Time Functionality
Time Goes On - Referenced from http://learnyousomeerlang.com/timeAfter release 18, Erlang time divided into multiple components:1. OS system time, also known as the POSIX time2. OS Monotonic time; some operating systems provide it, fairly stable
when available3. Erlang system time. It's the VM's take on POSIX time4. Erlang monotonic time. Erlang's view of the OS monotonic time if
available or VM's own monotonic version of system time5. Time offset; because the Erlang Monotonic time is a stable source of
authority, the Erlang system time will be calculated by having a given offset relative to the Erlang monotonic time. The reason for this is that it will allow Erlang to adjust the system time without modifying the monotonic time frequency.
Time Correction
Before release 18, Erlang time works in one of two major ways:1. The operating system's clock, represented as a tuple
of the form {MegaSeconds, Seconds, MicroSeconds} (os:timestamp())
2. The virtual machine's clock, represented as a tuple of the form {MegaSeconds, Seconds, MicroSeconds} (erlang:now(), auto-imported as now())
3. Fixed time offset calculated when vm starts
Time Changes – How to Survive Time Warps ?Why was Time Warp needed ?◉ Time correction was a compromise
between skewed clocks and inaccurate clock frequencies
◉ To avoid breaking events, the clock can only be corrected very slowly, so we could have both inaccurate clocks and inaccurate intervals for very long periods of time
◉ People used erlang:now() when they wanted monotonic and strictly monotonic time (useful to order events) or unique values
How to Survive Time Warps ?◉ To find system time:
erlang:system_time/0-1◉ To measure time differences: call
erlang:monotonic_time/0-1 twice and subtract them
◉ To define an absolute order between events on a node: erlang:unique_integer([monotonic])
◉ Measure time and make sure an absolute order is defined: {erlang:monotonic_time(), erlang:unique_integer([monotonic])}
◉ Create a unique number: erlang:unique_integer([positive])
Opensource Projects
Overview of some of the popular opensource projects written in Erlang
2
OPENSOURCE PROJECTS
ERLANG
Some very popular in
NOSQL world
Most popular
applicatio
n for E
rlang
Most suited for
distributed projects
Embeddable
webservers in Erlang
Applications like RabbitMQ & Ejabberd (used by Whatsapp)
Communication
Applications like yaws, mochiweb, cowboy etc
Webservers
Projects like OTP and applications like disco
Distributed
Applications like mnesia, couchdb & riak
Databases
OTPOTP (Open Telephony Platform) is set of Erlang libraries & design principles
providing middleware to develop distributed systems
Includes distributed db, language interfaces, debugging & release tools
Why Erlang ?Why choose Erlang for your next server side
application ?3
WHY ERLANG ? Referenced from http://veldstra.org/whyerlang/
Lightweight ConcurrencyProcesses are very lightweight, with only about 500 bytes of overhead per-process. This means that millions of processes can be created, even on older computers.
Transparent DistributionWith the exception of timing all operations in the distributed system will work in exactly the same way as they worked in a single-node system.
Hot Code ReplacementIn realtime control systems we may not want or may never be able to turn off the system to perform upgrades & such systems needs dynamic code upgrades.
Battle ProvenErlang has been successfully used in production systems for over 20 years (with reported uptimes of 9-nines — that's 31ms of downtime a year)
Soft Realtime ApplicationsErlang was developed at Ericsson and was designed from the ground up for writing scalable, fault-tolerant, distributed, non-stop, soft-realtime applications.
Free, Opensource & Much MoreReleased under permissive open-source license, cross platform support to run on linux, osx, windows, freebsd, solaris & vxworks. Much more, explore.
2,000,000+
EJABBERDMassive Scale – 2+ Million Concurrent Users on Single Node
https://blog.process-one.net/ejabberd-massive-scalability-1node-2-million-concurrent-users/
SOME REFERENCES◉ https://github.com/0xAX/erlang-bookmarks/wiki/Erlang-
bookmarks◉ https://github.com/drobakowski/awesome-erlang◉ https://github.com/uhub/awesome-erlang◉ http://learnyousomeerlang.com/the-hitchhikers-guide-to-
concurrency◉ https://github.com/erlang/otp◉ http://erlang.org/doc/apps/erts/erts.pdf ◉ http://highscalability.com/blog/2014/2/26/the-whatsapp-
architecture-facebook-bought-for-19-billion.html
THANKS!
Any questions?You can find me at
@digikrit / [email protected]
Special thanks to all the people who made and released these awesome resources for free: Presentation template by SlidesCarnival Presentation models by SlideModel Erlang by Ericsson, Erlang projects by ProcessOne, Basho, Apache, Pivotal & others