Giuseppe Maxia gives a presentation introducing Gearman, a technology for distributed computing. Gearman allows clients to submit tasks or jobs to a central server, which then distributes the jobs to registered worker processes and returns the results to the clients. It provides flexibility by allowing clients, servers, and workers to run on different operating systems and communicate using different programming languages. Gearman also enables redundancy through its ability to use multiple servers for high availability.

1. Gearman: a technology
for distributed
computing
Giuseppe Maxia
MySQL Community Team Lead
Sun Microsystems
Wednesday, 07 October 2009
This is a quick talk that introduces technologies in the age of cloud computing

2. about me -Giuseppe Maxia
 a.k.a. The Data Charmer
 MySQL Community Team Lead
 Long time hacking with MySQL features
 Formerly, database consultant, designer, coder.
 A passion for QA
 An even greater passion for open source
 ... and community
 Passionate blogger
http://datacharmer.blogspot.com
Wednesday, 07 October 2009

3. Mainframe
terminal
Mainframe
terminal
operating system
client
terminal
hardware
application
terminal
0 100
USER FRIENDLINESS
Wednesday, 07 October 2009
We start with a big of history of computing.
In the age of mainframes, users could only choose the whole system, or nothing. Hardware,
operating system, and software came from the same company. The only priority was towards
getting the job done with the minimal expenses. Users needs were negligible

4. Mini computers
Mainframe Mini terminal
terminal
operating system Mini
client
hardware terminal
application
terminal
0 100
USER FRIENDLINESS
Wednesday, 07 October 2009
Minicomputers added some level of flexibility to the user's experience, although the
information system was still (with little exceptions) a matter of choosing a company. The user
experience improved a bit, but only for very power users.

5. Networks
server personal
computer
personal
operating operating computer
system system
personal client
hardware hardware computer
hardware
personal
application
0 computer 100
USER FRIENDLINESS
Wednesday, 07 October 2009
Networks made a giant leap towards a better user experience.
Users were relatively free of choosing their hardware, possibly different operating systems,
although there was still only one application for the main business. Yes, users could run their
local applications (solitaire started being popular these days :-) ) but still the system was a bit
stiff

6. Web applications
web server browser
INTERNET
browser
operating operating
operating
system system systemoperating
system
client
browser
hardware hardware
hardware
application browser
0 100
USER FRIENDLINESS
Wednesday, 07 October 2009
More flexibility came with the adoption of web infrastructures. The most important being
freedom from close location. Web applications run quite well regardless of the location of the
servers, thanks also to the availability of better hardware and bandwidth. Applications for the
main business, though, remain stiff. Mainly, the business data is only accessible through one
set of applications, written in one language, and often tied to a specific operating system.

7. service
Cloud applications
provider service
provider
service
provider
service browser
provider web
INTERNET
server
browser
operating operating
operating
system system system
client
browser
hardware hardware
hardware
application applicationapplication browser
0 100
USER FRIENDLINESS
Wednesday, 07 October 2009
With cloud computing, the possibilities grow. Not only the clients are free of choosing
hardware and operating systems, but they can also share and choose different applications
that are available through providers, independently from the operating system and language
used by the clients.

8. Some actors
• memcached
• gearman
Used in production by Facebook and Digg
Wednesday, 07 October 2009
In this quick introduction, we will only mention a few popular systems that are used in
popular web sites. Memcached is a distributed cache environment that helps scaling the
performance of demanding web sites. Gearman is described in the next slides

9. GEARMAN
Wednesday, 07 October 2009
What is it? Pay attention to the spelling

10. != G ER M A N
Wednesday, 07 October 2009
Not "german"! It is not a language. It's a system, where a server accepts requests from clients,
sends the requests to workers and dispatches the answers back.

11. G E A R M A N?
Wednesday, 07 October 2009
And what exactly is it? Think about it. It's an anagram.
Do you know of somebody who doesn't do anything except telling the workers what to do
and then getting a "thank you" from clients?

12. MANAGER
Wednesday, 07 October 2009
of course! it's a MANAGER.

13. job
task
request
server worker client
http://gearman.org
Wednesday, 07 October 2009
Anyway, in Gearman, there are several concepts.
A worker will register with the server the list of tasks that it can perform.
A client will request jobs from the server. The server gives tasks to the workers, collects the
results, and passed them back to the clients.

14. Distributed
Wednesday, 07 October 2009
The beauty of Gearman is that everything can be on a different host.

15. Multiple operating systems
Wednesday, 07 October 2009
There is no difference if one of the actors is using one operating system rather than the same
one used by the server. Actually, clients can get specific advantage of this architecture, by
requesting tasks that are not available in their operating system but can be easily performed
in the OS of one of the workers.

16. multiple languages
Wednesday, 07 October 2009
Language, the greatest divider in the recent technology, is not an obstacle anymore. Clients
can keep coding in the language they are most familiar with, and the workers will use
libraries and classes that are only available to specific languages, without need for the clients
to be involved with the nitpicks of such complex systems.

17. freedom of
choice
Wednesday, 07 October 2009
Clients can really use several languages, and request tasks that are performed remotely in
any language.

18. redundancy
Wednesday, 07 October 2009
Gearman can be a robust system. It allows redundant servers for high availability. Each
worker can register its tasks to several servers, and every client can request a job from more
than one server.

19. More on similar matters
• Italian Perl Workshop, Pisa, 22-Oct-2009
• FOSS.MY, Kuala Lumpur, Malaysia, 25-Oct-2009
• CodeBits, Lisbon, Portugal, 3-4-5-Dec-2009
http://datacharmer.blogspot.com
http://gearman.org
Wednesday, 07 October 2009