Introduction to basic API's and best practices in Node.js

1. Node.js Learning Kit
Vipin Menon, Software Engineer, IBM
vipinmv1@in.ibm.com | @vipinmv | https://github.com/vipinmenon

2. Agenda
Introduction to Basic APIs and best practices.
Streams Buffers
Cluster Modules
Timers JSON
NPM Addons

3. stream - definition
Flowing data; perfect match for event architecture

4. stream – best practices
 Know your (data) producer, consumer and
backpressure

5. stream – best practices
 There are number of life cycle events for streams;
knowing and using those leads to efficient program
 Streams do not define data types, it flows your data as
is

6. buffer - definition
An abstraction around raw binary data

7. buffer - example

8. buffer – best practices
 Buffer is great for manipulating large in-memory data
 With `allocUnsafe()`, raw memory is exposed, so use it
with caution
 Buffer implies (large) memory, track your objects

9. cluster - definition
Share server load, exploit multiple cores

10. cluster - example
Master
Worker

11. cluster – best practices
 Use for single server multi-core exploitation; when load
grows beyond threshold, switch to horizontal scaling
 Don’t mix cluster with child_process – it adds complexity
 Session is not managed automatically, app needs to
implement one

12. modules - definition
Re-usable API abstractions

13. modules - example

14. modules – best practices
 Hide complexities under well defined APIs
 Avoid global state; avoid side effects (`process.exit`)
 Use discrete, disambiguating naming convention

15. timers - definition
Schedulers: Global APIs for future execution

16. timers - example

17. timers – best practices
 Don’t cover up program bugs with artificial delays
 `setInterval` is a recurring schedule, know when to shut
those down
 Don’t write code that critically rely on schedule precision

18. JSON - definition
 JavaScript Object Notation
 Data interchange format, native to JavaScript
 Specification for JS Object Marshalling / Unmarshalling

19. JSON - example

20. JSON – best practices
 Using a schema improves readability and speed
 Use shorter field names for serializable objects
 JSON processing is synchronous, so large (> 2 MB)
throttles the Node.js thread

21. NPM - definition
 Most popular JavaScript development tool registry
 Default Package manager for Node.js

22. npm - example

23. npm – best practices
 Known your modules! Audit and scan third party
modules periodically
 Use active and well maintained modules
 Lock your module dependencies

24. addons - definition
Foreign Function Interfacing; mainly C++

25. addons - example

26. addons – best practices
 Don’t directly deal with V8, use wrappers
 Addons run on main thread, don’t run tight loop code
 Many addon resources are not visible to Node.js so
use those under your control

27. Disclaimer
 The information contained in this presentation is provided for informational purposes only.
 While efforts were made to verify the completeness and accuracy of the information contained
in this presentation, it is provided “As Is”, without warranty of any kind, express or implied.
 In addition, this information is based on IBM’s current product plans and strategy, which are
subject to change by IBM without notice.
 IBM shall not be responsible for any damages arising out of the use of, or otherwise related to,
this presentation or any other documentation.
 Nothing contained in this presentation is intended to, or shall have the effect of:
 Creating any warranty or representation from IBM (or its affiliates or its or their supplies
and/or licensors); or
 Altering the terms and conditions of the applicable license agreement governing the use
of IBM software.

28. THANK YOU!