hrchu

How to get a stack trace for each thread in a running python script

Sometimes a python script will simply hang forever with no indication of where things went wrong. Perhaps it's polling a service that will never return a value that allows the program to move forward. Here's a way to see where the program is currently stuck.

Install gdb and pyrasite

Install gdb.

# Redhat, CentOS, etc

hrchu

@startuml
skinparam handwritten true
"You/Browser" -> slack.com: 1. I would like to access my files on Google Drive via your interface.
slack.com -> "You/Browser": 2. You should apply the "Authorization Code" from Google for me first.
"You/Browser" -> account.google.com: 3. I would like to permit slack.com to access my files.
account.google.com -> "You/Browser": 4. Are you sure?
"You/Browser" -> account.google.com: 5. [Y]
account.google.com -> "You/Browser": 6. Okay. Here is the "Authorization Code." Plz give it back to slack.com now.
"You/Browser" -> slack.com: 7. You can do what I asked now (with the Authorization Code which is just received from Google.) 
slack.com -> account.google.com: 8. I would like to exchange the "Authorization Code" for the "Access Token."

ixdy

Setting up ssh public key authentication on macOS using a YubiKey 4

I largely followed Florin's blog post, but have a few notes to add regarding issues I encountered:

Basic setup notes

1. I used a YubiKey 4, while the blog describes using a YubiKey NEO. I'm sure a YubiKey 5 would also work. I'm also running macOS 10.13.6.
2. I installed GPGTools as recommended. However, as I'll note later, it seems that gpg-agent only automatically starts when gpg is used; for ssh, you'll need to ensure it's running.
3. Before generating your keys, decide what key size you want to use. If you run the list command inside gpg --edit-card, look for the Key attributes line to see what is currently selected. On my YubiKey 4, it defaulted to 2048 bits for all keys:

Key attributes ...: rsa2048 rsa2048 rsa2048

hurricane-voronin

Naming Classes Without a 'Manager'

• SomethingManager
• Design Patterns
  • Creational
    • Factory Method
    • Abstract Factory
    • Builder
• Prototype

alexislucena

Install Scala 2.11.8

$ sudo apt-get remove scala-library scala
$ sudo wget www.scala-lang.org/files/archive/scala-2.11.8.deb
$ sudo dpkg -i scala-2.11.8.deb

Check Scala version

$ scala -version

xl7dev

> cd /Applications/VMware Fusion.app/Contents/Library/VMware OVF Tool
> ./ovftool --acceptAllEulas /Users/marco/Documents/Virtual\ Machines.localized/Windows\ 8.1\ x64.vmwarevm/Windows\ 8.1\ x64.vmx /Users/marco/Desktop/Win81.ova

edenhill

If your processing rate is high this might not be optimal since you'll be committing for each message, even if using async commits there's some degree of performance penalty.
So another alternative is to keep `enable.auto.commit` set to True (default) but disable the automatic offset store.
So what is the offset store?
Each time a message is passed from the client to your application its offset is stored for future commit, the next intervalled commit will then use this stored offset. If the stored offset did not change from the last commit nothing happens.

So by setting `enable.auto.offset.store` to False you keep the convenient intervalled auto commit behaviour but you control what offsets are actually eligible for commit.

ursuad

Kafka Topics

List existing topics

bin/kafka-topics.sh --zookeeper localhost:2181 --list

Describe a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --describe --topic mytopic

Purge a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --alter --topic mytopic --config retention.ms=1000

... wait a minute ...

bastman

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

hrchu

# Configuration file for runtime kernel parameters.
# See sysctl.conf(5) for more information.

# See also http://www.nateware.com/linux-network-tuning-for-2013.html for
# an explanation about some of these parameters, and instructions for
# a few other tweaks outside this file.

# See evil packets in your logs.
net.ipv4.conf.all.log_martians = 1