GitHub draft pull requests

Introducing draft pull requests - The GitHub Blog

Samsung Galaxy Fold: $2000

Samsung’s foldable phone is the $1,980 Galaxy Fold - The Verge



Huawei Mate X hands-on: our foldable future - The Verge

electric cars: (Volvo) Polestar vs. Tesla

The Polestar 2 is a Google-powered all-electric Tesla competitor - The Verge



Tesla's design is much nicer...

New Owner Frequently Asked Questions | Tesla

AWS IoT

a very informative podcast interview with VP of IoT with AWS

AWS Internet of Things with Dirk Didascalou - Software Engineering Daily


IoT Applications & Solutions | What is the Internet of Things (IoT)? | AWS



What is AWS IoT? 3 Min Overview - YouTube

RISC-V: Open-Source Hardware (OSH)

RISC-V - Wikipedia

"RISC-V (pronounced "risk-five") is an open-source hardware instruction set architecture (ISA) based on established reduced instruction set computer (RISC) principles.

In contrast to most ISAs, the RISC-V ISA is free and open-source and can be used royalty-free for any purpose, permitting anyone to design, manufacture and sell RISC-V chips and software. While not the first open-architecture[1] ISA, it is significant because it is designed to be useful in a wide range of devices. The instruction set also has a substantial body of supporting software, which avoids a usual weakness of new instruction sets.

The project began in 2010 at the University of California, Berkeley, but many contributors are volunteers and industry workers outside the university.[2]

The RISC-V ISA has been designed with small, fast, and low-power real-world implementations in mind,[3][4] but without over-architecting for a particular microarchitecture style"


RISC-V @ GitHub


info from:
Amazon just acquired Eero because Wi-Fi is key to the smart home - Stacey on IoT | Internet of Things news and analysis

AWS > Amazon

AWS Drives More Than Half of Amazon's Operating Income | Light Reading

"Amazon Web Services comprised just 11% of the company's overall sales in 2018, but delivered more operating income than all other business units combined.

In financial results delivered Thursday, Amazon Web Services Inc. drove $7.43 billion sales for the quarter ending December 31, up 45% from $5.11 billion year-over-year. (See Amazon Reports Q4 Sales Up 20% to $72.4B.)"

link from:
Microsoft Cloud Show - New Opportunities After Failures

React Native Rearchitecture

React Native Rearchitecture with G2i Team - Software Engineering Daily

React Native allows developers to build native applications for iOS and Android using components written in the React JavaScript framework. These ReactJS components render to native application code by going over a JavaScript bridge, a message bus that communicates between JavaScript code and native iOS or Android runtimes.

To address the performance issues of React Native, the core team working on React Native at Facebook is rearchitecting the React Native runtime within a project called Fabric. Fabric consists of changes to the threading model, the data handling system, and the JavaScript bridge.

corymsmith/react-native-fabric: A React Native library for Fabric, Crashlytics and Answers @GitHub

How React Native constructs app layouts (and how Fabric is about to change it)

"RN Fabric allows the UI thread (where UI is drawn) to be in sync with the JS thread (where the UI is programmed)"

this new engine may be more similar to NativeScript, a similar open source tool:

How NativeScript Works - YouTube

Zoox: self driving vehicles

Zoox

Zoox Self-Driving with Ethan Dreyfuss - Software Engineering Daily

React Context vs Redux

React.js
by Maximilian Schwarzmüller

Redux vs React's Context API

React Context vs Redux - Who wins? - YouTube

Context API + Hooks

React Hooks Crash Course

Posgres as "Document DB" with JSONB

Postgres JSON: Unleash the Power of Storing JSON in Postgres | Codeship | via @codeship

CREATE TABLE cards ( id integer NOT NULL, board_id integer NOT NULL, data jsonb );

INSERT INTO cards VALUES (1, 1, '{"name": "Paint house", "tags": ["Improvements", "Office"], "finished": true}');

SELECT data->>'name' AS name FROM cards

SELECT * FROM cards WHERE data->>'finished' = 'true';

CREATE INDEX idxfinished ON cards ((data->>'finished'));

As of Postgres 9.4, along with the JSONB data type came GIN (Generalized Inverted Index) indexes. With GIN indexes, we can quickly query data using the JSON operators @>, ?, ?&, and ?

CREATE INDEX idxgindata ON cards USING gin (data); 

SELECT count(*) FROM cards WHERE data @> '{"tags": ["Clean", "Kitchen"]}';
How to query JSONB, beginner sheet cheat – Hacker Noon


PostgreSQL: Documentation: 10: 8.14. JSON Types

Fission: Serverless Functions for Kubernetes: FaaS

fission/fission: Fast Serverless Functions for Kubernetes @ GitHub, Apache 2 license

written in GoLang, supporting execution environments for
Go, JVM. .NET, NodeJS, Python, Ruby, PHP, and even Perl :)

A trigger is something that maps an event to a function; Fission as of today supports HTTP request, timed, and message queue triggers.

Performance: 100msec cold start
Fission maintains a pool of "warm" containers that each contain a small dynamic loader. When a function is first called, i.e. "cold-started", a running container is chosen and the function is loaded. This pool is what makes Fission fast: cold-start latencies are typically about 100msec.
Serverless Functions for Kubernetes - Fission

"What is Fission?
Fission is a framework for serverless functions on Kubernetes.

Write short-lived functions in any language, and map them to HTTP requests (or other event triggers).

Deploy functions instantly with one command. There are no containers to build, and no Docker registries to manage."

Fission: An open source, Kubernetes-native Serverless Framework | Getting Started: Composing Serverless Functions with Fission Workflows (Part 1)  (Part 2)

Serverless Functions for Kubernetes tutorial


How Fission.io Brings Serverless to Kubernetes - The New Stack

Fission: Serverless on Kubernetes with Soam Vasani - Software Engineering Daily



Fission: Serverless Functions for Kubernetes [B] - Soam Vasani, Platform9 Systems - YouTube

Function as a Service on Kubernetes with Fission.io - YouTube
demo by Brendan Burns, co-creator of K8S

Open Source Workflow Engines

Workflow Processing Engine Overview 2018: Airflow vs Azkaban vs Conductor vs Oozie vs Amazon Step Functions - Shawn's Pitstop

• Airflow
• Azkaban
• Conductor
• Oozie
• AWS Step Functions

Data pipelines, Luigi, Airflow: everything you need to know

NoFlo | Flow-Based Programming for JavaScript

Flow-based programming - Wikipedia

The Microservice Workflow Automation Cheat Sheet – berndruecker

flowing-retail/rest at master · berndruecker/flowing-retail


Top 10 Free And Open Source BPM Software for Businesses

"Business process management software primarily serves the purpose of providing a platform for people to design, build, analyze, modify and the test the various business processes."

Java Workflow Engines Comparison

List of BPMN 2.0 engines - Wikipedia

List of BPEL engines - Wikipedia

Activiti (software) - Wikipedia

Flowable - Wikipedia (fork of Activity)

AWS Step Functions + Simple Workflow Service (SWF)

Amazon Simple Workflow Service - Cloud Workflow Development - AWS

What is Amazon Simple Workflow Service? - Amazon Simple Workflow Service

"When using Amazon SWF, you implement workers to perform tasks. These workers can run either on cloud infrastructure, such as Amazon Elastic Compute Cloud (Amazon EC2), or on your own premises. You can create tasks that are long-running, or that may fail, time out, or require restarts—or that may complete with varying throughput and latency. Amazon SWF stores tasks and assigns them to workers when they are ready, tracks their progress, and maintains their state, including details on their completion. To coordinate tasks, you write a program that gets the latest state of each task from Amazon SWF and uses it to initiate subsequent tasks. Amazon SWF maintains an application's execution state durably so that the application is resilient to failures in individual components. With Amazon SWF, you can implement, deploy, scale, and modify these application components independently."

Introduction to Amazon SWF - Amazon Simple Workflow Service

How Amazon SWF Works - Amazon Simple Workflow Service

Simple Workflow Service (SWF) - Ugly Duckling or Beautiful Swan? [AWS South Wales User Group] - YouTube

Automating Analytic Workflows on AWS | AWS Big Data Blog

Two Years with Amazon Simple Workflow (SWF) | Kobi's Blog

"What is SWF not?

• SWF does not execute any code.
• SWF does not contain the logic of the workflow.
• SWF does not allow you to draw a workflow or a state machine

How does it work?

SWF is based on polling. Your code runs on your machines on AWS or on-premises – it doesn’t matter. Your code is polling for tasks from the SWF API (where they wait in queues), receives a task, executes it, and sends the result back to the SWF API.
SWF then issues new tasks to your code, and keeps the history of the workflow (state)."

neyric/aws-swf-toolkit: A Node.js Framework for workflows on Amazon SWF


AWS Step Functions

"Build distributed applications using visual workflows

AWS Step Functions lets you coordinate multiple AWS services into serverless workflows so you can build and update apps quickly. Using Step Functions, you can design and run workflows that stitch together services such as AWS Lambda and Amazon ECS into feature-rich applications. Workflows are made up of a series of steps, with the output of one step acting as input into the next. Application development is simpler and more intuitive using Step Functions, because it translates your workflow into a state machine diagram that is easy to understand, easy to explain to others, and easy to change. You can monitor each step of execution as it happens, which means you can identify and fix problems quickly. Step Functions automatically triggers and tracks each step, and retries when there are errors, so your application executes in order and as expected."

AWS Step Functions - FAQs

"You should consider using AWS Step Functions for all your new applications, since it provides a more productive and agile approach to coordinating application components using visual workflows. If you require external signals to intervene in your processes, or you would like to launch child processes that return a result to a parent, then you should consider Amazon Simple Workflow Service (Amazon SWF). With Amazon SWF, instead of writing state machines in declarative JSON, you write a decider program to separate activity steps from decision steps. This provides you complete control over your orchestration logic, but increases the complexity of developing applications. You may write decider programs in the programming language of your choice, or you may use the Flow framework to use programming constructs that structure asynchronous interactions for you."

Getting Started - AWS Step Functions

{ "Comment": "A Hello World example of the Amazon States Language using a Pass state", "StartAt": "HelloWorld", "States": { "HelloWorld": { "Type": "Pass", "Result": "Hello World!", "End": true } } }

ASL: Amazon States Language - AWS Step Functions

{ "Comment": "An example of the Amazon States Language using a choice state.", "StartAt": "FirstState", "States": { "FirstState": { "Type": "Task", "Resource": "arn:aws:lambda:us-east-1:123456789012:function:FUNCTION_NAME", "Next": "ChoiceState" }, "ChoiceState": { "Type" : "Choice", "Choices": [ { "Variable": "$.foo", "NumericEquals": 1, "Next": "FirstMatchState" }, { "Variable": "$.foo", "NumericEquals": 2, "Next": "SecondMatchState" } ], "Default": "DefaultState" }, "FirstMatchState": { "Type" : "Task", "Resource": "arn:aws:lambda:us-east-1:123456789012:function:OnFirstMatch", "Next": "NextState" }, "SecondMatchState": { "Type" : "Task", "Resource": "arn:aws:lambda:us-east-1:123456789012:function:OnSecondMatch", "Next": "NextState" }, "DefaultState": { "Type": "Fail", "Error": "DefaultStateError", "Cause": "No Matches!" }, "NextState": { "Type": "Task", "Resource": "arn:aws:lambda:us-east-1:123456789012:function:FUNCTION_NAME", "End": true } } }

State Types:

• Common State Fields
• Pass: passes input to output
• Task: single unit of work; main building block for state machines; properties
• "Type": "Task",
• "Resource": "arn:aws:lambda:..."
• "TimeoutSeconds": 300,  // optional
• "HearthbeatSeconds": 60 // optional
• "Next": "NextState1"
• "Retry": [ { "ErrorEquals": ["CustomError"]. "IntervalSeconds": 1, "MaxAttempts": 5 }]
• "Catch": [ { ... }
• Choice: conditional branching logic ("if statement", "switch", create loops)
• { "Choices": [ { "Variable": "$.foo", "NumericEquals": 1, "Next", "MatchOne" } ... 
• "And": [...], "Not": [...], "Or": [...]
• Wait: delay execution
• "Seconds": 10  ==> wait 10 seconds before next state
• "Timestamp": "2020-01-01T00:00:00Z" // wait until specified time
• "SecondsPath": "$.waitseconds" // use input variable
• "TimestampPath": "$.expirydate" // use input var
• Succeed: end state
• "SuccessState": { Type": "Succeed" }
• Fail: end state
• "FailState": { "Type": "Fail", "Cause": "Data error", "Error": "inventory low" }
• Parallel: parallel execution
• "StateP1": { "Type": "Parallel", "Next": "FinalState",
  "Branches" : [ { "StartAt": "Wait 20s", " States: { "Wait 20s" { ... } } }, 

Input and Output Processing for State/Task; using "$" with field names;
using "path" to filter portion of input for processing and output; example

{ "numbers": [2, 3], "sum": 5 }

{ "Type": "Task", "Resource": "arn:aws:lambda:us-east1:123:function:Add", "Next", "NextStep",
"InputPath": "$.numbers", "ResultPath": "$.sum", "OutputPath": "$.sum" }

State Machine Data - AWS Step Functions

Amazon States Language - AWS Step Functions

Develop and Test AWS Step Functions Workflows Locally

"You can now use a local version of AWS Step Functions to develop and test your workflows."

course: AWS Developer: Lambda Deep Dive @ Pluralsight
Using Step Functions to Control Flow

Azure Logic Apps + Microsoft Flow

workflow cloud platforms

Logic App Service | Microsoft Azure

What are Microsoft Flow, Logic Apps, Functions, and WebJobs? - Azure | Microsoft Docs

"Microsoft Flow and Logic Apps are both designer-first integration services that can create workflows. Both services integrate with various SaaS and enterprise applications.
Microsoft Flow is built on top of Logic Apps. They share the same workflow designer and the same connectors."
"Functions and Logic Apps are Azure services that enable serverless workloads. Azure Functions is a serverless compute service, whereas Azure Logic Apps provides serverless workflows. Both can create complex orchestrations. An orchestration is a collection of functions or steps, called actions in Logic Apps, that are executed to accomplish a complex task. For example, to process a batch of orders, you might execute many instances of a function in parallel, wait for all instances to finish, and then execute a function that computes a result on the aggregate."
Azure Logic Apps Documentation - Tutorials, API Reference | Microsoft Docs

"Azure Logic Apps is a cloud service that helps you automate and orchestrate tasks, business processes, and workflows when you need to integrate apps, data, systems, and services across enterprises or organizations. Logic Apps simplifies how you design and build scalable solutions for app integration, data integration, system integration, enterprise application integration (EAI), and business-to-business (B2B) communication, whether in the cloud, on premises, or both.

To build enterprise integration solutions with Azure Logic Apps, you can choose from a growing gallery with 200+ connectors, which include services such as Azure Service Bus, Functions, and Storage; SQL, Office 365, Dynamics, Salesforce, BizTalk, SAP, Oracle DB, file shares, and more. Connectors provide triggers, actions, or both for creating logic apps that securely access and process data in real time."


"Every logic app workflow starts with a trigger, which fires when a specific event happens, or when new available data meets specific criteria. Many triggers include basic scheduling capabilities so that you can specify how regularly your workloads run. For more custom scheduling scenarios, start your workflows with the Schedule trigger. Learn more about how to build schedule-based workflows.

Each time that the trigger fires, the Logic Apps engine creates a logic app instance that runs the actions in the workflow. These actions can also include data conversions and flow controls, such as conditional statements, switch statements, loops, and branching."
Quickstart - Create and automate your first workflow - Azure Logic Apps | Microsoft Docs

Enterprise integration with Azure Logic Apps | Microsoft Docs

Microsoft/vscode-azurelogicapps: Azure Logic Apps extension for VS Code @ GitHub

for low code / no code apps:

Automate processes + tasks | Microsoft Flow

"Turn repetitive tasks into multistep workflows. For example, with a few clicks capture tweets and add them as leads in Dynamics 365, subscribers in Mailchimp, and more...

Start with a template..."

Azure Logic Apps - An Overview | DotNetCurry

"Microsoft Azure LogicApps Components:

• Workflow – is used to define the different steps of your business process, using a graphical user interface.
• Triggers - initiate a workflow, and create a new instance of the workflow. A trigger can be an arrival of a file on FTP site or receiving an email. Types of triggers:
• Poll triggers: These triggers poll your service at a specified frequency to check for new data. When new data is available, a new instance of your logicapp runs with the data as input.
• Push triggers: (Webhooks) These triggers listen for data on an endpoint, or for an event to happen, then triggers a new instance of your logicapp.
• Recurrence trigger: This trigger instantiates an instance of your logicapp on a prescribed schedule.
• Event-based triggers: i.e. message from service bus queue
• Actions - An action represents a step in the workflow.
  It can invoke an operation on your API.
• Connectors - are used to connect to different data sources and services.
  Azure LogicApps provide an in-built set of managed connectors that cover different areas like social media, file FTP and many more.
• Enterprise Integration Pack (EIP) Connectors - provide functionality like BizTalk.
  These connectors are used for complex enterprise integration scenarios such as XML messaging and Validation. It supports exchange messages through industry-standard protocols, including AS2, X12, and EDIFACT. It requires an "Integration Accounts" to store different artifacts, like schemas, partners, certificates, maps and agreements

Online training classes:

Azure Logic Apps: Getting Started | Pluralsight

Azure Logic Apps: Getting Started : Building Blocks

• "Connectors" are pre-built wrappers around systems (web service APIs); there are about 200 built-in connects, and you can build your own (that is just an API)
• "Triggers": to initiate a Logic App; could be "reactive" and "proactive" (see above list); could leverage "trigger templates" and "pre-built templates"; Not all connectors could be triggers
• "Actions": building blocks of Logic Apps; most of Actions are also Connectors.
  Actions is just "next step" in a logic app. 
• "Flow Control": sequence of logic in Logic App
• "if-then", "switch", "for-each", "do-until", "scope"

Microsoft Azure Developer: Creating Enterprise Logic Apps | Pluralsight

Azure Logic Apps: Fundamentals | Pluralsight

Data operation samples - Azure Logic Apps | Microsoft Docs

"actions": {
   "Initialize_variable_-_integer_array": {
      "type": "InitializeVariable",
      "inputs": {
         "variables": [ 
            {
               "name": "myIntegerArray",
               "type": "Array",
               "value": [
                  1,
                  2,
                  3,
                  4
               ]
            }
         ]
      },
      "runAfter": {}
   },
   "Select": {
      "type": "Select",
      "inputs": {
         "from": "@variables('myIntegerArray')",
         "select": {
            "Product_ID": "@item()"
         }
      },
      "runAfter": {
         "Initialize_variable_-_integer_array": [
           "Succeeded"
         ]
      }
   }
},

Schedule and run automated tasks and workflows with Azure Logic Apps | Microsoft Docs

"triggers": {
   "Recurrence": {
      "type": "Recurrence",
      "recurrence": {
         "frequency": "Week",
         "interval": 1,
         "schedule": {
            "hours": [
               10,
               12,
               14
            ],
            "minutes": [
               30
            ],
            "weekDays": [
               "Monday"
            ]
         },
         "startTime": "2017-09-07T14:00:00",
         "timeZone": "Pacific Standard Time"
      }
   }
}

azure-quickstart-templates/101-function-app-create-dynamic at master · Azure/azure-quickstart-templates @ GitHub

JavaScript Workflow Engines, State Machines, Statecharts, React Automata

"JavaScript Promises are just a state machines"

(Finite) State Machine is based on "events" that cause transitions between states. Usually there is a nice graphical presentation of such states and events.

When systems get more complex there are "state-charts" with some useful tools to help.

Workflow Engine vs. State Machine:
"In a workflow engine, transition to the next step occurs when a previous action is completed, whilst a state machine needs an external event that will cause branching to the next activity."

Workflows and state transitions can be defined as meta-data (i.e. JSON or XML files), and tools can dynamically generate GUI and process events.

Workflows are also essential part of  "Business Process Modelling" (BPM). (Business process management) "enterprise" tools.

Videos:

David Khourshid - Infinitely Better UIs with Finite Automata - YouTube

David Khourshid: Simplifying Complex UIs with Finite Automata & Statecharts | JSConf Iceland 2018 - YouTube

Get Started with Redux - Scenic City Summit 2017 - YouTube

Informative docs:
Welcome to the world of Statecharts - Statecharts (statecharts.github.io)

"a statechart is a beefed up state machine. The beefing up solves a lot of the problems that state machines have, especially state explosion that happens as state machines grow"

What is a state machine? - Statecharts
"a state machine is a software component that defines:

• The machine is defined by a finite list of states.
• One state is defined as the initial state. When a machine is “started” it automatically enters this state.
• States can define “events” that trigger a transition.
• A transition causes the machine to exit the state and enter another (or the same) state.
• A transition may be conditional, in other words might ask “the world” about things. These are called guards and must be side-effect free.
• A state can define actions upon entering or exiting a state. These are called actions and will typically have side effects."

Comparison of popular Javascript workflow libs downloads in last 6 months:

fsm-iterator vs javascript-state-machine vs machina vs xstate | npm trends



GitHub repos and docs of those libs:

davidkpiano/xstate: State machines and statecharts for the modern web.


Super quick start | XState Docs

XState Version 4 Released 🚀 – David Khourshid – Medium


Robust React User Interfaces with Finite State Machines | CSS-Tricks

Responsive web design tool, CMS, and hosting platform | Webflow



jakesgordon/javascript-state-machine: A javascript finite state machine library




ifandelse/machina.js: js ex machina - finite state machines in JavaScript


jfairbank/fsm-iterator: A finite state machine iterator for JavaScript
by jfairbank (Jeremy Fairbank) / Repositories


fschaefer/Stately.js: Stately.js is a JavaScript based finite-state machine (FSM) engine for Node.js and the browser.


Standard data format for representing state machines for the web

State Chart XML (SCXML): State Machine Notation for Control Abstraction
Statechart XML from W3C



Related helpful tools and sites:

MicheleBertoli/react-automata: A state machine abstraction for React

"A state machine abstraction for React that provides declarative state management and automatic test generation."

spectrum.chat/statecharts

State Machine: State Explosion - Statecharts

"The main problem that’s stopping widespread usage of state machines is the fact that beyond very simple examples, state machines often end up with a large number of states, a lot of them with identical transitions.

" Statecharts solve this state explosion problem:"

In statecharts, states can be organized hierarchically.


A guard is a sort of pre condition to a transition, in a way it stops a transition from happening if some condition is not true.