cpq

Why stack grows down

Any running process has several memory regions: code, read-only data, read-write data, et cetera. Some regions, such as code and read-only data, are static and do not change over time. Other regions are dynamic: they can expand and shrink. Usually there are two such regions: dynamic read-write data region, called heap, and a region called stack. Heap holds dynamic memory allocations, and stack is mostly used for keeping function frames.

Both stack and heap can grow. An OS doesn't know in advance whether stack or heap will be used predominantly. Therefore, an OS must layout these two memory regions in a way to guarantee maximum space for both. And here is the solution:

1. Layout static memory regions at the edges of process's virtual memory
2. Put heap and stack on edges too, and let them grow towards each other: one grows up, one grows down

abtrout

Password-store keeps your passwords (or any other sensitive information) saved in GnuPG encrypted files organized in ~/.password-store. For more information about GPG, consult the GNU Privacy Handbook.

Getting started

To get started, install pass and generate a keypair.

$ brew install pass
$ gpg --gen-key
$ gpg --list-keys

kchida

- What do Etcd, Consul, and Zookeeper do?
  - Service Registration:
    - Host, port number, and sometimes authentication credentials, protocols, versions
      numbers, and/or environment details.
  - Service Discovery:
    - Ability for client application to query the central registry to learn of service location.
  - Consistent and durable general-purpose K/V store across distributed system.
    - Some solutions support this better than others.
    - Based on Paxos or some derivative (i.e. Raft) algorithm to quickly converge to a consistent state.
    - Centralized locking can be based on this K/V store.

sivel

Better SSH Authorized Keys Management

A seemingly common problem that people encounter is how to handle all of your users authorized_keys file.

People struggle over management, ensuring that users only have specific keys in the authorized_keys file or even a method for expiring keys. A centralized key management system could help provide all of this functionality with a little scripting.

One piece of functionality overlooked in OpenSSH is the AuthorizedKeysCommand configuration keyword. This configuration allows you to specify a command that will run during login to retrieve a users public key file from a remote source and perform validation just as if the authorized_keys file was local.

Here is an example directory structure for a set of users with SSH public keys that can be shared out via a web server:

lsd

Upgrading to Lion or Yosemite and WebStorm 9, I noticed key repeat was
turned off for the IdeaVim plugin h j k l keys.

System-wide key repeat

defaults write -g ApplePressAndHoldEnabled -bool false in a terminal will enable
key repeat for every app. This can alternatively be found in the accessibility settings in OS X' preferences.

App specific key repeat

ifduyue

[Unit]
Description=Beanstalkd is a simple, fast work queue

[Service]
User=nobody
Restart=always
RestartSec=500ms
ExecStart=/usr/local/bin/beanstalkd -b /var/lib/beanstalkd
LimitNOFILE=10240

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

ryboe

# use the latest ubuntu environment (18.04) available on travis
dist: bionic

language: go

# You don't need to test on very old versions of the Go compiler. It's the user's
# responsibility to keep their compiler up to date.
go:
  - 1.16.x

veekaybee

Anti-hype LLM reading list

Goals: Add links that are reasonable and good explanations of how stuff works. No hype and no vendor content if possible. Practical first-hand accounts of models in prod eagerly sought.

Foundational Concepts

Pre-Transformer Models