sbilello

Installing pyenv on macOS for Zsh using Homebrew

Published May-13-2020

• Installation
• Basic Usage
• Virtualenv

sbilello

import java.io.IOException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.BitSet;
import java.util.List;
import java.util.concurrent.ThreadLocalRandom;
import java.util.stream.Stream;

sbilello

Code is clean if it can be understood easily – by everyone on the team. Clean code can be read and enhanced by a developer other than its original author. With understandability comes readability, changeability, extensibility and maintainability.

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General rules

1. Follow standard conventions.
2. Keep it simple stupid. Simpler is always better. Reduce complexity as much as possible.
3. Boy scout rule. Leave the campground cleaner than you found it.
4. Always find root cause. Always look for the root cause of a problem.

Design rules

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Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

sbilello

SSH agent forwarding and screen

When connecting to a remote server via SSH it is often convenient to use SSH agent forwarding so that you don't need a separate keypair on that server for connecting to further servers.

This is enabled by adding the

ForwardAgent yes

option to any of your Host entries in ~/.ssh/config (or alternatively with the -A option). Don't set this option in a wildcard Host * section since any user on the remote server that can bypass file permissions can now als use keys loaded in your SSH agent. So only use this with hosts you trust.

sbilello

#!/usr/bin/env bash

##
# This configures an S3 bucket ObjectCreated notification for the given Lambda
# function so that when a file is uploaded the Lambda function is invoked. This
# is useful when the bucket is not defined in the same CloudFormation template
# as the function. CloudFormation cannot setup the notification in this case.
#
# Note that the AWS CLI is used and will require valid AWS credentials for the
# account containing the resources. The 'jq' JSON processor is also required

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---
execution:
- write-xml-jtl: full
  scenario: shire
  executor: jmeter
  concurrency: 100
  ramp-up:  5m
  hold-for: 15m
  throughput: 60

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execution:
- concurrency: 100
  ramp-up: 1m
  hold-for: 5m
  scenario: quick-test

scenarios:
  quick-test:
    requests:
    - http://blazedemo.com

sbilello

Let's suppose we have 2 datacenters
dc1
dc2

Available Reaper configuration options:
1) datacenterAvailability: ALL
 
create keyspace reaper_db with replication = {'class' : 'NetworkTopologyStrategy', 'dc1': 3, 'dc2': 3};

1 Reaper instance handling the entire cluster with 2 datacenters

sbilello

Default

Powerlevel9k