PragProg Customers

Distributed Services with Go: accessing the service outside the pods (Beta-4 pg.223)

csrfr

csrfr

Distributed Services with Go: accessing the service outside the pods (Beta-4 pg.223)

Once deployed, I am not able to access the service outside the prolog pods. I can run the client successfully and access the service from a client running on one of the proglog pods.

However, I am not able to access the service from the following locations:

  1. Laptop: The client connection hangs and then returns connection error while dialing dial tcp: lookup proglog-0.proglog.mysvcs.svc.cluster.local: no such host. I am dialing using the EXTERNAL-IP address of proglog-0 from k8s in the client (This address works when used from a proglog pod).

  2. From a pod in the k8s cluster but not a proglog pod. It prints the following error repeatedly ERROR: 2020/10/31 18:59:29 [core] subconn returned from pick is not *acBalancerWrapper. Also, the acBalancerWrapper error appears when running the client from a proglog pod (where it usually works) from time to time.

Anyone faced this before, ideas?
At the moment I’m looking into GetServers returning the K8s DNS names (e.g. proglog-0.proglog.default.svc.cluster.local:8400 rather than the EXTERNAL-IP of the pods.

5 comments
#question/book-distributed-services-with-go
5 944 5

Marked As Solved

travisjeffery

travisjeffery

Author of Distributed Services with Go

Yeah we should return ErrNoSubConnAvailable like so:

func (p *Picker) Pick(info balancer.PickInfo) (
	balancer.PickResult, error) {
	p.mu.RLock()
	defer p.mu.RUnlock()
	var result balancer.PickResult
	if strings.Contains(info.FullMethodName, "Produce") ||
		len(p.followers) == 0 {
		result.SubConn = p.leader
	} else if strings.Contains(info.FullMethodName, "Consume") {
		result.SubConn = p.nextFollower()
	}
	if result.SubConn == nil {
		return result, balancer.ErrNoSubConnAvailable
	}
	return result, nil
}

so gRPC will block the RPC until a new picker is available with available sub connections.

2
Post #4

Also Liked

travisjeffery

travisjeffery

Author of Distributed Services with Go

For 1. did you port-forward the pod/service to expose it outside k8s’ network? That’s what the $ kubectl port-forward pod/proglog-0 8400 8400 command in the book is for.

  1. Could be because leader election is still underway so a nil subconn is returned for it.
1
Post #2
travisjeffery

travisjeffery

Author of Distributed Services with Go

For 2. I think the error handling should be improved. I’m looking into it.

1
Post #3

Where Next?

View thread on forum
View Distributed Services With Go's book portal
Post errata for this book
Post a suggestion for this book
Post a question about this book
Post a review about this book
question
Home PragProg Customers
#question/book-distributed-services-with-go
5 944 5
Last post

Popular Pragmatic Bookshelf topics Top

simonpeter
PragProg Customers

Web Development with Clojure, Third Edition: (create-migration "guestbook") not working (page 9)
When I try the command to create a pair of migration files I get an error. user=> (create-migration "guestbook") Execution error (Ill...
#errata/book-web-development-with-clojure-third-edition
5 1788 4
New
adamwoolhether
PragProg Customers

Distributed Services with Go: receiving Unknown flag: --go_opt when compiling protobuf (page 20)
When trying to generate the protobuf .go file, I receive this error: Unknown flag: --go_opt libprotoc 3.12.3 MacOS 11.3.1 Googling ...
/book-distributed-services-with-go
0 4924 3
New
leonW
PragProg Customers

Python Testing with pytest, Second Edition: File not Found Error (page 43)
I ran this command after installing the sample application: $ cards add do something --owner Brian And got a file not found error: Fil...
#errata/book-python-testing-with-pytest-second-edition
5 4391 7
New
jgchristopher
PragProg Customers

Programming Phoenix LiveView: live_modal/2 instead of live_component/3 (210)
“The ProductLive.Index template calls a helper function, live_component/3, that in turn calls on the modal component. ” Excerpt From: Br...
#errata/book-programming-phoenix-liveview
3 1042 6
New
oaklandgit
PragProg Customers

Hands-on Rust: Failed to Load Texture error (page 121)
Hi, I completed chapter 6 but am getting the following error when running: thread 'main' panicked at 'Failed to load texture: IoError(O...
/book-hands-on-rust
2 1310 3
New
akraut
PragProg Customers

Programming Phoenix LiveView: Display Image Uploads (pdf p142)
The markup used to display the uploaded image results in a Phoenix.LiveView.HTMLTokenizer.ParseError error. lib/pento_web/live/product_l...
#errata/book-programming-phoenix-liveview
2 2102 9
New
bjnord
PragProg Customers

Hands-on Rust: Chapter 3: Can't get first hello to run
Hello @herbert ! Trying to get the very first “Hello, Bracket Terminal!" example to run (p. 53). I develop on an Amazon EC2 instance runn...
#question/book-hands-on-rust
0 1147 2
New
redconfetti
PragProg Customers

Docker for Rails Developers - 'docker-machine' command deprecated (page 156)
Docker-Machine became part of the Docker Toolbox, which was deprecated in 2020, long after Docker Desktop supported Docker Engine nativel...
/book-docker-for-rails-developers#suggestion
0 896 0
New
SlowburnAZ
PragProg Customers

Machine Learning in Elixir:Error installing EXLA dependency - Page 25
Getting an error when installing the dependencies at the start of this chapter: could not compile dependency :exla, "mix compile" failed...
#errata/book-machine-learning-in-elixir
1 1159 10
New
dachristenson
PragProg Customers

Kotlin and Android Development featuring Jetpack: End Ch. 11 app runs but consistently crashes
I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...
#question/book-kotlin-and-android-development-featuring-jetpack
0 936 8
New

Other popular topics Top

AstonJ
General Dev>Dev Chat

Best chairs for developers?
What chair do you have while working… and why? Is there a ‘best’ type of chair or working position for developers?
#workspace#opinions
74 5463 41
New
AstonJ
General Dev>Hardware

Poll: Which keyboard layout do you use?
poll poll Be sure to check out @Dusty’s article posted here: An Introduction to Alternative Keyboard Layouts It’s one of the best write-...
colemakmods.github.io
#polls/keyboards
10 6048 11
New
AstonJ
General Dev>Hardware

Custom keyboard keycaps
There’s a whole world of custom keycaps out there that I didn’t know existed! Check out all of our Keycaps threads here: https://forum....
#hardware/keyboards#keycaps#mechanical-keyboards
15 11086 19
New
DevotionGeo
General Dev>Code Editors

Dendron: a personal knowledge management tool on top of VSCode
/vscode#visual-studio-code
30 7372 9
New
AstonJ
General Dev>Hardware

Planck vs Preonic vs Subatomic (Keyboards)
I ended up cancelling my Moonlander order as I think it’s just going to be a bit too bulky for me. I think the Planck and the Preonic (o...
/keyboards#mechanical-keyboards#ortholinear#planck#preonic
105 17596 47
New
PragmaticBookshelf
Frontend>Learning Resources

Modern CSS with Tailwind
Tailwind CSS is an exciting new CSS framework that allows you to design your site by composing simple utility classes to create complex e...
pragprog.com
#pragprog/tailwind#published-book/book-modern-css-with-tailwind
12 5813 4
New
PragmaticBookshelf
Backend>Learning Resources

Programming Phoenix LiveView
Build highly interactive applications without ever leaving Elixir, the way the experts do. Let LiveView take care of performance, scalabi...
pragprog.com
#pragprog/elixir/phoenix#published-book/book-programming-phoenix-liveview
79 10732 24
New
AstonJ
General Dev>Dev Chat

Languages Without Garbage Collection
Continuing the discussion from Thinking about learning Crystal, let’s discuss - I was wondering which languages don’t GC - maybe we can c...
#garbage-collection
21 5575 7
New
PragmaticBookshelf
Community>In The Spotlight

Spotlight: Erin Dees (Author) Interview and AMA!
Author Spotlight Erin Dees @undees Welcome to our new author spotlight! We had the pleasure of chatting with Erin Dees, co-author of ...
#author-spotlight/ruby/rails/book-effective-testing-with-rspec-3/book-seven-more-languages-in-seven-weeks/book-cucumber-recipes#rspec
24 4247 11
New
PragmaticBookshelf
Backend>Learning Resources

Advanced Functional Programming with Elixir
Use advanced functional programming principles, practical Domain-Driven Design techniques, and production-ready Elixir code to build scal...
joekoski.com
#pragprog/elixir#published-book#functional-programming/book-advanced-functional-programming-with-elixir
43 4989 22
New
Back to top

Latest in Distributed Services with Go

Distributed Services with Go Portal ❯

PragProg Customers

Pragmatic Bookshelf PragProg Customers ❯

Latest on Devtalk

Devtalk ❯

We ❤️ helpful members!

We reward our most helpful members via our MOTM scheme - by giving away a whopping 25 books per year!

Member of the Month

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

Categories:

Sub Categories:

Popular Portals

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

We're in Beta

About us Mission Statement See our Roadmap