edit poc

poc-datacollector/modules/ROOT/nav.adoc

@@ -1,6 +1,7 @@
 * xref:index.adoc[datacollector]
 * xref:index-structure.adoc[project structure]
 ** xref:index-vuejs.adoc[Vue.js]
+** xref:index-nodejs.adoc[Node JS]
 ** xref:index-mongo.adoc[Mongo]
 ** xref:index-redis.adoc[Redis]
 * xref:index-src.adoc[src-files]

poc-datacollector/modules/ROOT/pages/index-nodejs.adoc

@@ -0,0 +1,60 @@
+=  NodeJS -> services readmongo_service, dummy_service
+
+
+
+TIP: As an asynchronous event-driven JavaScript runtime, Node.js is designed to build scalable network applications.
+
+Almost no function in Node.js directly performs I/O, so the process never blocks. Thanks to this, scalable systems is very reasonable to be developed in Node.js.
+
+https://nodejs.org/en/docs/guides/blocking-vs-non-blocking/[Overview of Blocking vs Non-Blocking^]
+
+TIP: *Node.js* is similar in design to, and influenced by, systems like *Ruby's Event Machine* and *Python's Twisted.*
+
+Node.js takes the event model a bit further. It presents an *event loop as a runtime construct* instead of a library.
+
+*In other systems, there is always a blocking call to start the event-loop.*
+
+Typically,
+
+- behavior is defined through callbacks at the beginning of a script,
+
+- and at the end a server is started through a blocking call like *EventMachine::run().*
+
+[NOTE]
+====
+In Node.js, there is no such start-the-event-loop call.
+
+- *Node.js* simply *enters the event loop after executing the input script.*
+
+- *Node.js exits the event loop* when there are *no more callbacks to perform.*
+====
+
+
+Node.js being *designed without threads* doesn't mean you can't take advantage of multiple cores in your environment.
+
+Child processes can be spawned by using our *child_process.fork() API,* and are designed to be easy to communicate with.
+
+TIP: Built upon that same interface is the cluster module, which *allows you to share sockets between processes* to enable load balancing over your cores.
+
+
+=== Video = intro
+
+
+****
+TIP: NodeJS in 10 Minutes and Netflix
+
+video::2gQG4cFjahw[youtube]
+
+video::CZ3wIuvmHeM[youtube]
+****
+
+netflix
+
+* 6:50 monolithic
+* 8:24 minroservices
+* 19:00 microservice
+* 37:00
+
+https://netflix.github.io[Netflix on Github]
+
+