Michael F. Collins gave a presentation about different ways for programs to communicate and collaborate. He discussed parent-child processes where a parent process spawns a child process and they communicate through standard input/output streams. He also covered distributed processes using various protocols like SOAP, REST, and Thrift. Additionally, he explained asynchronous messaging where programs communicate by sending one-way messages via a broker.

1. MAKING PROGRAMS TALK
MICHAEL F. COLLINS, III
DESERT CODE CAMP
OCTOBER 18, 2014

2. ABOUT ME
• PRODUCT ARCHITECT/LEAD DEVELOPER FOR NEURON ESB, A MESSAGING
MIDDLEWARE PRODUCT
• 20+ YEAR CAREER (1994-2014)
• STUDIED COMPUTER ENGINEERING AT CSU SACRAMENTO (GO HORNETS!)
• CURRENTLY WORK FOR NEUDESIC (6+ YEARS); PRIOR EMPLOYERS INCLUDE
SOGETI USA, JDA SOFTWARE, KAISER IT, NONSTOP SOLUTIONS, PEOPLESOFT,
AND OTHERS
• DEVELOP FOR WINDOWS, LINUX, MAC OSX, IOS, ANDROID, AND OTHER
PLATFORMS
• FAVORITE LANGUAGES: C#, C++, JAVA, RUBY, PYTHON, GO, ERLANG

3. CONTACT ME
• EMAIL:
• MICHAEL.COLLINS@NAKEDCODERS.BIZ
• MICHAEL.COLLINS@NEUDESIC.COM
• TWITTER: @MFCOLLINS3
• SKYPE: MFCOLLINS3
• LINKED IN: HTTP://WWW.LINKEDIN.COM/IN/MICHAELFCOLLINS3/

4. WHY ARE WE HERE?
• HOW DO TWO OR MORE PROGRAMS TALK?
• HOW CAN PROGRAMS COLLABORATE TO GET WORK DONE?
• WHAT STRATEGIES EXIST FOR PROGRAM COLLABORATION?
• WHAT ARE THE PITFALLS OF MULTI-PROGRAM DEVELOPMENT?

5. PARENT-CHILD PROCESSES
• PARENT PROCESS “SPAWNS” A CHILD
PROCESS
• “STANDARD I/O STREAMS” ARE USED
TO CONTROL AND COLLECT
FEEDBACK:
• 1 INPUT STREAM (STDIN)
• 2 OUTPUT STREAMS (STDOUT,
STDERR)
Parent
Child

6. PARENT-CHILD PROCESSES
• PARENT SENDS A COMMAND TO THE
CHILD USING STDIN
• CHILD SENDS A RESPONSE BACK TO
THE PARENT USING STDOUT
• CHILD CAN OUTPUT DIAGNOSTIC
INFORMATION (LOG DATA; DEBUG
MESSAGES) USING STDERR
Parent
Child

7. PARENT-CHILD PROCESSES
• SINGLE RESPONSIBILITY PRINCIPAL
• A PROGRAM SHOULD HAVE ONE REASON TO CHANGE
• DO ONE THING AND DO IT WELL
• GUI FOR COMMAND-LINE INTERFACE (CLI)
• PRESENT A GUI OVER POWERSHELL SCRIPTS OR COMMAND-LINE PROGRAMS
• USE A TEXT PROTOCOL
• EASY TO DEBUG FROM THE COMMAND LINE
• CAN BE SCRIPTED OR AUTOMATED FOR TESTING

8. DEMO
PARENT-CHILD PROCESSES

9. DISTRIBUTED PROCESSES
Client Server

10. DISTRIBUTED PROCESSES
• SOAP
• REST/HTTP
• PROTOCOL BUFFERS
• APACHE THRIFT
• SOCKETS
Client Server

11. DISTRIBUTED PROCESS PROTOCOLS
SOAP
XML-BASED PROTOCOL
PROVEN TECHNOLOGY
GREAT .NET SUPPORT (WCF)
STANDARDS FOR SECURITY,
RELIABILITY, DISCOVERY,
METADATA
LIMITED SUPPORT FOR OTHER
PLATFORMS/LANGUAGES
REST
HTTP-BASED
LOW BARRIER TO ENTRY
HIGHLY PORTABLE BETWEEN
PLATFORMS AND LANGUAGES
MOST LANGUAGES HAVE BASIC
HTTP SUPPORT
STABLE SECURITY STANDARDS
(HTTPS, OAUTH)
THRIFT
HIGHLY PORTABLE BETWEEN
PLATFORMS AND LANGUAGES
STANDARD FOR METADATA
API-BASED
SECURITY THROUGH SSL

12. DISTRIBUTED PROCESSES
• USE THE BEST PROTOCOL FOR YOUR PROJECT
• DO YOU NEED ADVANCED SECURITY, DISCOVERABILITY, DISTRIBUTED TRANSACTIONS,
RELIABILITY, AND YOU’RE ON .NET ONLY?
• USE WCF AND SOAP
• DO YOU NEED PORTABILITY AND THE ABILITY FOR MULTIPLE TECHNOLOGIES TO
INTEGRATE?
• USE REST OR THRIFT
• ARE YOU EXPOSING A PUBLIC API OVER THE INTERNET?
• USE REST
• ARE YOUR SERVICES FOR AN INTERNAL INTERNET?
• USE THRIFT

13. DEMO
DISTRIBUTED PROCESSES

14. ASYNCHRONOUS MESSAGING
Broker
Participant Participant Participant

15. ASYNCHRONOUS MESSAGING
• COMMUNICATION IS HANDLED VIA
ONE-WAY MESSAGES SENT BETWEEN
PARTICIPANTS
• A BROKER PROVIDES SERVICES SUCH
AS A MESSAGE QUEUE OR PUBLISH-SUBSCRIBE
ARCHITECTURE TO
DELIVER MESSAGES TO RECEIVERS
Broker
Participa
nt
Participa
nt
Participa
nt

16. ASYNCHRONOUS MESSAGING
• POINT-TO-POINT: DELIVERED AT
MOST ONCE
• PUBLISH-SUBSCRIBE: DELIVERED TO
ALL SUBSCRIBERS
Broker
Participa
nt
Participa
nt
Participa
nt

17. ASYNCHRONOUS MESSAGING
• MESSAGES MAY BE PERSISTED BEFORE
BEING DELIVERED
• SOME MESSAGES CAN BE PROCESSED
IN A TRANSACTION
• RELIABLE MESSAGING IF A
PARTICIPANT IS UNAVAILABLE
Broker
Participa
nt
Participa
nt
Participa
nt

18. ASYNCHRONOUS MESSAGING
• POISON MESSAGE QUEUE: MESSAGES
THAT CAUSE FAILURES
• DEAD LETTER QUEUE: MESSAGES
THAT EXPIRE BEFORE BEING
DELIVERED
• RELIABLE == NO MESSAGE LOSS!
• GUARANTEED == MESSAGE WILL BE
DELIVERED, OR YOU WILL KNOW
THAT IT WAS NOT DELIVERED
Broker
Participa
nt
Participa
nt
Participa
nt

19. ASYNCHRONOUS MESSAGING
• MSMQ
• MQ SERIES
• ACTIVE MQ
• RABBIT MQ
• ZEROMQ
Broker
Participa
nt
Participa
nt
Participa
nt

20. ASYNCHRONOUS MESSAGING
• PATIENCE IS YOUR FRIEND
• TEST, TEST, TEST
• CAPTURE POISON MESSAGES AND DEAD
LETTER MESSAGES
• ANYTHING YOU DO SLOWS YOUR SYSTEM
DOWN
• PERSISTENCE
• TRANSACTIONS
• GUARANTEED DELIVERY
• MAXIMIZE I/O

21. DEMO
ASYNCHRONOUS MESSAGING

22. Q&A
ASK ME ANYTHING!

23. NEUDESIC IS HIRING!
• ARE YOU ONE OF THE BEST SOFTWARE DEVELOPERS IN THE DESERT? IF YES,
WHAT ARE YOU WAITING FOR?
• NEUDESIC HIRES THE BEST-OF-THE-BEST AND IS LOOKING FOR TALENTED
SOFTWARE DEVELOPERS, UX DESIGNERS, BI DEVELOPERS, QA ENGINEERS, AND
PROJECT MANAGERS!
• PHOENIX IS ONE OF THE BEST LOCATIONS TO WORK IN!
• JOIN A GROWING COMPANY AND MAKE IT MORE SUCCESSFUL!!!
• EMAIL ME YOUR RESUME TODAY: MICHAEL.COLLINS@NEUDESIC.COM

24. CONTACT ME (AGAIN)
• EMAIL:
• MICHAEL.COLLINS@NAKEDCODERS.BIZ
• MICHAEL.COLLINS@NEUDESIC.COM
• TWITTER: @MFCOLLINS3
• SKYPE: MFCOLLINS3
• LINKED IN: HTTP://WWW.LINKEDIN.COM/IN/MICHAELFCOLLINS3/