Golang Logging With Channels

GoLang Workspace Setup To work with rabbitMQ in our Golang project, we'll need some basic setup. Channels allow us to pipe data from one goroutine to another (even using the pipe operator!). 5 in the parameter sendch chan<- int. ansible ansible api docker docker api elasticsearch etcd gevent golang golang channel golang gc golang redis. Buffered channel. Please let me know if this code can be improved in any way. Yielding Functions for Iteration in Go 22 Dec 2016. Taxes may apply. We use cookies for various purposes including analytics. Golang: errors, routines, and channels I've been working in Golang for a few months now. A study of how computers can be linked to share data. Middlewares in Go: Best practices and examples. This issue affects the version of golang package in Red Hat Enterprise Linux 7. Go Lang for Tourists (glft : golang) 4. Success: process exited with code 0. ”Golang后端开发工程师“年薪300000RMB+ 全球招聘【IPFS GOLANGBP 2019-10-25 18:30 招聘 1024程序员快乐,怎么用一句话把程序员夸上天?. It provides an API that lets you use image recognition to build AI-enabled apps. If the program contains tests or examples and no main function, the service runs the tests. Welcome to NLog! NLog is a flexible and free logging platform for various. Celery is an asynchronous task queue/job queue based on distributed message passing. It's using channels since the lines could be added VERY frequently and I don't want to consume I/O time on the receiving function (outside of this package). Please keep in mind that the Go Playground is deterministic, meaning you should get the same result each time you run a program on the https://play. 2) clientreceiver() wait for his data from client via networkconnection and send it to a inputchannel to handlingINOUT. Comparing these, we can see the main change is with the "idle" time. Using the log package will give you everything you need to be a good. There is a little difference between string and []byte. Go by Example: Non-Blocking Channel Operations Basic sends and receives on channels are blocking. GitHub Gist: instantly share code, notes, and snippets. While languages such as Java and C continue to dominate programming, new models have emerged that are better suited to modern computing, particularly in the cloud. Golang for Network Ops. function return values and parms). Golang: Implementing kafka Consumers & Producers using sarama In this post I will tell you briefly about what is Kafka. Special syntax is used to operate on them; <-ch is an expression that causes the executing goroutine to block until a value comes in over the channel ch, while ch <- x sends the value x (possibly blocking until another goroutine receives the. Google developed golang to fullfill very specific needs. An unbuffered channel. Golang channels - quit channel. Here’s the worker goroutine. 10 from Ubuntu Universe repository. The intentions of this post is to host a minimalist set of examples on working with files using Golang. Imp points. One of those tasks is one-to-many communication. After struggling on the fact that "learning a new language is tough", I could manage to make the code work as follows (I was looking for some ways to simplify the code, but I gave up…). Sends to a buffered channel block only when the buffer is full. Those messages are not compatible with RFC 3164. A breakdown forces Jason Rygaard to choose between his crew's safety and finishing the job. However, the log files usually are fairly large. This is the second part of React Apollo Client Subscription frontend which uses Golang backend. 请注意,本文正文含有大量链接。如果是转载或者使用某些不支持超链接的阅读器,就请自行脑补吧。 近期,Go Team 连续放出了几个大招来介绍即将在八月问世的 Go 1. Additionally, they are very easy to use, with just a few notational syntaxes to remember. That’s why our goal is to take you from Golang beginner to Go web developer by enrolling in this course. Like Loading. 0~git20160511. Sameer Ajmani 29 July 2014 Introduction. Golang Guide: A List of Top Golang Frameworks, IDEs, and Tools Go is quickly rising up the programming charts. Enroll for $249. Demo code is implemented with Golang’s buffered channel. 8 - if else statement 9 - Loops 10 - Switch Statement. Channel in Go provides a connection between two goroutines, allowing them to communicate and synchronize the exchange of any resource that is passed through it. Ability to set different log levels for different source files. For example, if one goroutine sends values on a channel and a second goroutine receives them, the values are received in the order sent. Go by Example: Non-Blocking Channel Operations Basic sends and receives on channels are blocking. Resumé after 6 months of Golang, the Good, the Bad, the Ugly. One of the most basic task when working on a server is the ability to effectively operate with the files and file system. Although our systems are not designed specifically for high security applications, they must use minimum standards of encryption and authentication. As we all know that logging is essientially significant for server side programming because in general logging the only way to report what happens inside the program. The server code is a DRM (digital rights management) system, called Readium LCP. Topics include writing goroutines and implementing channels for communications between goroutines. Jaana Burcu Dogan 4 October 2016 Introduction. The Go programming language, sometimes referred to as Google's golang, is making strong gains in popularity. Retrieve my uploads. Faced with similar growing pains, a small team of Google engineers built a language called Golang, or Go for short, in 2007 to address these issues. The go snap package will be updated automatically when updates are available. This is a little more Go like, ListDirectory returns a channel over which directory entries will be passed. It’s not efficient to read all data to the driver, and scatter them out to the cluster. Golang is a free and open source programming language created by Google in 2007. Check out this great reference of tools, frameworks, and IDEs for this powerful language. Channels are an excellent way to do this. Yesterday was an exciting day. Channels ("-") Channels ("-") with Select Channels ("-") with worker pools Defer GoLang Panic and Recover String Formatting JSON SQLite Modules 1 (Creating a new module) Modules 2 (Adding Dependencies) AWS SDK for Go (S3 listing) Linked List Binary Search Tree (BST) Part 1 (Tree/Node structs with insert and print functions). Google developed golang to fullfill very specific needs. GoLang, being one such revolutionary discovery, has taken the entire world by storm. If your programs are going to be logging information, it is best to follow the destination conventions. What I'd like instead is for the stream to be real-time, that is, when tt sends something to stdout, it should be parsed immidately and streamed onto stdoutCh. 5 in the parameter sendch chan<- int. Please keep in mind that the Go Playground is deterministic, meaning you should get the same result each time you run a program on the https://play. Like Loading. Typical supported operations are presented below using the example of the libthread channel API. This tutorial is available in a video format, if you want to support me and my work then please feel free to leave a like and subscribe to my channel for my content! A Simple REST API So, we are going to be using the code from one of my other articles, Creating a simple REST API in Go , to get us started. It is very common for me to design code that expects functions to return an iterable context, particularly because I have been developing in Python with the yield statement. 2) clientreceiver() wait for his data from client via networkconnection and send it to a inputchannel to handlingINOUT. need more details before I can give more direction though. Your keyword was too generic, for optimizing reasons some results might have been suppressed. compile speed. Continue reading Using Prometheus to monitor MQ channel status. Posts in it are meant to provide short and informative introductions to various topics. Concurrent programming is a large topic but it's also one of the most interesting aspects of the Go language. This is true because we will batch get all the items in the buffered channel. One of the primary requirements for the systems we build is something we call the "minimum security requirement". Channels ("-") Channels ("-") with Select Channels ("-") with worker pools Defer GoLang Panic and Recover String Formatting JSON SQLite Modules 1 (Creating a new module) Modules 2 (Adding Dependencies) AWS SDK for Go (S3 listing) Linked List Binary Search Tree (BST) Part 1 (Tree/Node structs with insert and print functions). The inverse of io. Generators are rather familiar objects in Python. GitHub Gist: instantly share code, notes, and snippets. d2af3a6-4_all. Celery is an asynchronous task queue/job queue based on distributed message passing. Grokbase › Groups › Go › golang-dev runtime error: send on closed channel goroutine 22 [running]: log/syslog. The sendData function converts this channel to a send only channel in line no. Golang Basic tutorial is one of the best online platforms to learn the Go programming language. Return Value. 62 func New(out io. Go, which is also referred to as "Golang," is a compiled systems-oriented programming language started by Google in 2007. Channel is already logged at irclogs. However, the log files usually are fairly large. For one, you can use them just about anywhere (e. Ability to set different log levels for different source files. It is defined by chan and must be initialized using make (similar to slices, maps). Golang for Network Ops. Recently I started a series of articles about Gang of Four Design Patterns and their adoption in Golang. Lets assume that everything that is produced needs to be consumed, even if the process receives a SIGTERM. 50 Shades of Go: Traps, Gotchas, and Common Mistakes for New Golang Devs 50 Shades of Go in Other Languages. The Go programming language, sometimes referred to as Google's golang, is making strong gains in popularity. The additional signal channel is closed by its only sender, which holds the channel closing principle. Using the log package will give you everything you need to be a good. A message on this channel ends the ListObjects iterator. In this example, the channel dataCh is never closed. To get started, we will download Golang on our development machine and setup our workspace. This tutorial is available in a video format, if you want to support me and my work then please feel free to leave a like and subscribe to my channel for my content! A Simple REST API So, we are going to be using the code from one of my other articles, Creating a simple REST API in Go , to get us started. Select is useful which we are dealing with multiple channels together and we need to fetch from the channel whichever is ready with value. Golang (atau biasa disebut dengan Go) adalah bahasa pemrograman baru yang dikembangkan di Google oleh Robert Griesemer, Rob Pike, dan Ken Thompson pada tahun 2007 dan mulai diperkenalkan di publik tahun 2009. 僕はJava方面に慣れていますのでslf4j(Logback)やlog4j2の様なロギングライブラリがあると扱い易いなぁ…と思う次第です。. Mattermost 3. The fact that this trivial example which is a bad fit for channels in the first place can be solved with a mutex doesn't really illustrate much on its own, but the lack of discussion about the actual solution is odd. They're sort of the canonical way of solving channel closing synchronization. As I sometimes hear that GoLang (Go Programming Language) is good for concurrent programming, I just tried on the similar logic. One of the most basic task when working on a server is the ability to effectively operate with the files and file system. 首先是golang自带的package log。 使用godoc查看, godoc -http=:8001 ,然后就可以在 localhost:8001/pkg/log 就可以查看了。 最重要的是SetOutput这个函数,原型是 func SetOutput(w io. A study of how computers can be linked to share data. What I need to do should have a pretty simple solution: I want to ignore a request to get a result from a channel in golang, if you need to know the particular situation I have a link to my code. A Python `for value in something` in Golang Posted on 2018-11-20 by André Toscano in Golang , Programming , Python This is a dumb reminder but you know, sometimes is faster to have a reminder for this kind of code. This Go example parses Accept-Language string in HTTP request header and output (languageTag, quality) pairs:. This package provides the means of querying the log from an application. A simple golang web server with basic logging, tracing, health check, graceful shutdown and zero dependencies - main. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. It's using channels since the lines could be added VERY frequently and I don't want to consume I/O time on the receiving function (outside of this package). golang memory leak. This specialization introduces the Go programming language from Google and provides learners with an overview of Go's special features. We will use Go's channels to feed data from the driver to the executors, and read the outputs out also via channels. As opposed to Java, Go is compiled to machine code and is executed directly. If parsing RSS fails, then try to parse the content in Atom 1. Posts in it are meant to provide short and informative introductions to various topics. As I sometimes hear that GoLang (Go Programming Language) is good for concurrent programming, I just tried on the similar logic. Introduction. Let's dive straight in and look at what a WaitGroup is and what problem it solves for us. What I'd like instead is for the stream to be real-time, that is, when tt sends something to stdout, it should be parsed immidately and streamed onto stdoutCh. The function runtime. I've really started to like the language and how similar it is to Python. Experience with blockchain and security protocols is a major plus. Ability to set different log levels for different source files. It was a great course which covers wide range of topics around testing in golang. If you run it several times on your local machine with the go run command you should see that sometimes x is -5 and sometimes it's 17 because you can't predict which order the goroutines will be executed in, or if they are. Go is syntactically similar to C, but with memory safety, garbage collection, structural typing, and CSP-style concurrency. list method to retrieve a list of videos uploaded to the channel associated with the request. Lets have a db package that should provide a repository struct as a singleton object. Golang by example: Deactivate bombs hacking with golang. For example, if one goroutine sends values on a channel and a second goroutine receives them, the values are received in the order sent. Go attributes, such as speed of development and deployment, also work perfectly for this task. It is very small, has no external dependencies, except the standard Golang library and is actively being developed. Yesterday was an exciting day. Generators are rather familiar objects in Python. Each worker is given a reference to the channel when it's started. ) as well as freely-configurable multi-level logging. I recently saw an article from Uber Engineering describing an issue they were having with an increase in latency. Golang, programming language made in heavens 01 Feb 2015. close(c) // closes the channel (only sender should close) // Read from channel and test if it has been closed // If ok is false, channel has been closed v, ok := <-ch // Read from channel until it is closed for i := range ch {fmt. 3 - Variables 4 - Types 5 - Constants. The additional signal channel is closed by its only sender, which holds the channel closing principle. It was wrong and golang comes with various and extensive toolsets for testings. Handling CTRL-C (interrupt signal) in Golang Programs details using a goroutine and a couple of channels. A message on this channel ends the ListObjects iterator. Receives block when the buffer is empty. Let's talk about logging This is a post inspired by a thread that Nate Finch started on the Go Forum. His influence is everywhere: Unix, Plan 9 OS, The Unix Programming Environment book, UTF-8, and most recently the Go programming…. How to search the wiki, find related articles and view the wiki offline. An unbuffered channel. Server has three part which are running as goroutines and communicate via channels. After struggling on the fact that "learning a new language is tough", I could manage to make the code work as follows (I was looking for some ways to simplify the code, but I gave up…). Golang: Implementing kafka Consumers & Producers using sarama In this post I will tell you briefly about what is Kafka. Like Loading. This issue affects the version of golang package in Red Hat Enterprise Linux 7. Here is a golang example that shows what happens when you try and close a channel twice: Source: (example. With maps, it returns the key of the next key-value pair. Sends to a buffered channel block only when the buffer is full. Select is useful which we are dealing with multiple channels together and we need to fetch from the channel whichever is ready with value. Benchmarks will likely not be supported since the program runs. Note that we should define the struct with lowercase letters in order to make it private. But it's not just the language that makes Go special - Go has broad and consistent standard libraries and powerful but simple tools. 3 - Variables 4 - Types 5 - Constants. Welcome to NLog! NLog is a flexible and free logging platform for various. For example, a project. What I'd like instead is for the stream to be real-time, that is, when tt sends something to stdout, it should be parsed immidately and streamed onto stdoutCh. Putting it all. Enjoy even. Js Vs Golang | How to Choose the Best Backend Technology Node. In our case, we've got titles, keywords, and URLs that link to the articles. When a channel is created with no capacity, it is called an unbuffered. As I understand it there is no concurrent use of len happening here. When using strings together with i/o APIs, explicit conversion to []byte is usually required. For logging, we'd like you to use Event Tracing for Windows (ETW) instead of creating your own. A channel will be eventually garbage collected if no goroutines reference it any more, whether it is closed or not. Go will make you love programming again. After struggling on the fact that "learning a new language is tough", I could manage to make the code work as follows (I was looking for some ways to simplify the code, but I gave up…). A “for” statement with a “range” clause iterates through all entries of an array, slice, string or map, or values received on a channel. Info mode: Channels, Archives, Alerts, Live Monitor Replay mode: Search, Replay, Build Incidents, Export MP-840 USB LINE OUT HEADPHONES VOLUME COMMUNICATIONS LOGGING RECORDER COMMUNICATIONS LOGGING RECORDER. Join his newsletter ’Master the World of Golang'. Binary semaphores (mutexes) are special counting semaphores, each of binary semaphores can have at most one owner at any time. func·001(0xc200000bf0, 0xc200000be8, 0xc2000ae2a0,. The buffered channel named channel is the glue between the two pieces of code. Using Einstein Vision Within Golang. We are looking for an experienced Golang Developer with at least 3 years experience to help develop and support our scaling platform for Ethereum. On my machine, each channel operation of Golang takes ~75 nano-sec and each Chan (in C#) operation takes ~90 nano-sec. Let's dive straight in and look at what a WaitGroup is and what problem it solves for us. I find it a bit odd that the author didn't mention wait groups. Go is a lovely little programming language designed by smart people you can trust and continuously improved by a large and growing open-source community. (database, file, console) and change the logging configuration on-the-fly. 7 we introduced HTTP tracing, a facility to gather fine-grained information throughout the lifecycle of an HTTP client request. You just saw a simple example of concurrency in a Golang application that uses goroutines and channels. It is described as the systems development language. Use this wizard to create or select a project in the Google Developers Console and automatically turn on the API. It also has a predefined 'standard' Logger accessible through helper functions Print[f|ln], Fatal[f|ln], and Panic[f|ln], which are easier to use than creating a Logger manually. Posts in it are meant to provide short and informative introductions to various topics. As we all know that logging is essientially significant for server side programming because in general logging the only way to report what happens inside the program. Channel Concepts And Syntaxes. It's using channels since the lines could be added VERY frequently and I don't want to consume I/O time on the receiving function (outside of this package). Main logic of the parseFeedContent function:. 10 from Ubuntu Universe repository. Comparing these, we can see the main change is with the "idle" time. Below You can see My simple implementation of go quit channel. Up to this point, our web app takes ~5000ms (5 seconds), to load, which is atrocious. RabbitMQ is lightweight and easy to deploy on premises and in the cloud. Armed with Goroutines and the select statement, you can build correct, efficient and understandable concurrent programs that do complex things. This is the first post in the practical Golang series. Second, it exposes a Log function which takes a byte array (the event to log). The package includes handlers for logging in standardised formats, compressing HTTP responses, validating content types and other useful tools for manipulating requests and responses. Help:Editing Tutorial on editing articles and introduction to wiki text syntax. If you need only the events for a specific channel then use myevents, otherwise use a combination of filters to narrow down the events you wish to receive on the socket. Welcome to NLog! NLog is a flexible and free logging platform for various. Jobs, Code, Videos and News for Go hackers - everything about the go programming language. Our program pulls the data from the sitemaps fresh on every load. One of those tasks is one-to-many communication. Is Go Object Oriented? Go is not a pure object oriented programming language. Placing a go statement before a function call starts the execution of that function as an independent concurrent thread in the same address space as the calling code. Learn how to use Pusher Channels to support service discovery when creating a microservices architecture. Your keyword was too generic, for optimizing reasons some results might have been suppressed. Standard log levels (Debug, Info, etc. If you're coming from a JS/Node background, you need to learn some new programming concepts such as coroutines, channels, strict typing with compilation, interfaces, structs, pointers, and some other differences. Welcome to tutorial no. Welcome to NLog! NLog is a flexible and free logging platform for various. Go Lang for Tourists (glft : golang) 4. The function runtime. golang memory leak. background. The Google Go programming language is robust, simple, and easy to maintain. And it looks that the "bytes" package and "strings" package are almost the same. We had just launched a golang service that I had helped develop, and were excited to see it being used. In Golang the static member of the Singleton struct is declared as a global variable in the package that contains this type. Go attributes, such as speed of development and deployment, also work perfectly for this task. If the size of the channel’s buffer is zero, then the channel is unbuffered. Try for FREE. Imp points. Golang has to compile very fast enormous amounts of code; all your code: Google mostly uses its own libraries. As we all know that logging is essientially significant for server side programming because in general logging the only way to report what happens inside the program. Here’s the worker goroutine. close(c) // closes the channel (only sender should close) // Read from channel and test if it has been closed // If ok is false, channel has been closed v, ok := <-ch // Read from channel until it is closed for i := range ch {fmt. Explore the roles of channels and goroutines in implementing concurrency. o/ You win when console prints: Status: Operational All bombs deactivated! Rules: The code bellow can only be changed at: setupBombs(), testGrid(), BombGrid{} and Bomb{}. The reason why many developers adopt Golang is its built-in concurrency, which enables you to carry out many processes at the same time. Channels are the pipes that connect concurrent goroutines. examples of golang context and channels. js is much weaker in terms of parallel processes for big projects compared to Golang, which was specifically designed to overcome possible issues in this area. list method with the mine parameter set to true to retrieve the playlist ID that identifies the channel's uploaded videos. go sent job 1 received job 1 sent job 2 received job 2 sent job 3 received job 3 sent all jobs received all jobs The idea of closed channels leads naturally to our next example: range over channels. Use the left and right arrow keys or click the left and right edges of the page to navigate between slides. Python's logging module, for example, provides a function to retrieve the root logging object, which one can call methods on to customize the logging behaviour. Reading from ticker by multiple goroutines is quite simple. Using Golang to Build Microservices at The Economist: A Retrospective to deliver content to increasingly diverse digital channels. Frank Harkness is caught in a whiteout while moving the excavator on a narrow mountainside logging road. 5 这个划时代的版本。. In the previous tutorial, we discussed about how concurrency is achieved in Go using Goroutines. I get asked quite often where the traditional network engineer / network ops should start if they want to broaden their horizons with better code hacking skills or they have spent the last 20 years using Perl scripts or more recently Python and need a change. 0~git20160511. This use of a semaphore mimics a typical "worker pool" pattern, but without the need to explicitly shut down idle workers when the work is done. Unless the channels make the code inside cases of one select statement concurrent - which will be super confusing for me. Sends to a buffered channel block only when the buffer is full. Panic close of closed channel Question: Why do I get a "panic: close of closed channel" when trying to close a channel? Answer: Once a channel has been closed, you cannot close it a second time. Golang features goroutines and channels were designed to meet modern tech demand. If your programs are going to be logging information, it is best to follow the destination conventions. With PS Vue there is never an annual contract and no hassle. More than one close() is red flag because, unless all uses of the channel are carefully written and tested, it can lead to a panic on close of closed channel. But it’s not just the language that makes Go special – Go has broad and consistent standard libraries and powerful but simple tools. We will use Go's channels to feed data from the driver to the executors, and read the outputs out also via channels. Receives block when the buffer is empty. The second project is a WHOIS client which shows how. This may be annoying. I'd like to frame this around the OWASP Top 10 for now, but of course discussing any real-world examples people have come across would also be extremely helpful. Channel과 Process는 다 vs다 관계(어떤 프로세스가 받을지 모른다. [In case you don't know already: Golang methods can return multiple values at the same time!] Lets see a simple golang code example snippet that will make it easier to understand better:. Today it involves web technologies, wireless trends and social media development. Lots of people have an opinion of how logging should be done and logging libraries are fairly trivial to create, so even if they released the internal library used at Google it did non prevent logging libraries to pop up like mushrooms. There is a little difference between string and []byte. What I need to do should have a pretty simple solution: I want to ignore a request to get a result from a channel in golang, if you need to know the particular situation I have a link to my code. list method to retrieve a list of videos uploaded to the channel associated with the request. Channel is a built-in type in Go that is a fixed size FIFO. Each application can have one channel or many, and each client can choose which channels it subscribes to. With array and slices, it returns the index of the item as integer. Golang have a funny toy: Channel. The Go Sample App container is updated with the docker image okteto/golang:1. This post focuses on Go, but if you can see your way past that, I think the ideas presented here are widely applicable. Go is a general-purpose language that bridges the gap between efficient statically typed languages and productive dynamic language. The ability to iterate rapidly over multiple terabytes of data across user interactions comprehensively has dramatically improved our audience intelligence. Modify the example to overfill the buffer and see what happens. Agouti is a library for writing browser-based acceptance tests in Google Go. Golang channels tutorial December 6, 2013. 61 // The flag argument defines the logging properties. The server code is a DRM (digital rights management) system, called Readium LCP. We haven't use apollo-boost as it will not work with the subscription as that is our aim to accomplish here. GinkgoWriter aggregates input while a test is running and only dumps it to stdout if the test fails. I get asked quite often where the traditional network engineer / network ops should start if they want to broaden their horizons with better code hacking skills or they have spent the last 20 years using Perl scripts or more recently Python and need a change. A channel is created by the make function, which specifies the chan keyword and a channel's element type. Channels: Channels are a typed conduit through which you can send and receive values with the channel operator, <-. Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. It can used on its own. However, the log files usually are fairly large. I read the documentation and blog posts, watched videos, tried out some of the "hello world" examples and even wasted a couple of days trying to solve the puzzles for day 18 from Advent of Code 2017 using goroutines and failed spectacularly. Reader is io. Check out this great reference of tools, frameworks, and IDEs for this powerful language. From T-Mobile to Runtastic, RabbitMQ is used worldwide at small startups and large enterprises. Channel Concepts And Syntaxes. Comparing Golang with Java Golang Is Impressive. The out variable sets the 59 // destination to which log data will be written. 10 from Ubuntu Universe repository. But, once you get into the groove, you'll find Golang easier and faster to use. ArchWiki:Contributing The starting point for those willing to contribute to the wiki. 6 - Functions 7 - Packages. Writer) ,决定了log应该输出到什么地方,默认是标准输出。. Today it involves web technologies, wireless trends and social media development. Red Flag 1: More Than One close() When reviewing code that uses channels, first thing I do is search for close() on every channel. A buffered channel which has a buffer capacity greater than 0. GoLang, being one such revolutionary discovery, has taken the entire world by storm. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: