encoreshao

#!/bin/bash

red='\e[91m'
green='\e[92m'
yellow='\e[93m'
magenta='\e[95m'
cyan='\e[96m'
none='\e[0m'
_red() { echo -e ${red}$*${none}; }
_green() { echo -e ${green}$*${none}; }

encoreshao

How To Configure PostgreSQL 12 Streaming Replication in Ubuntu 18.04

• Build two boxes and install ubuntu18.04

  • box1: master -> Ubuntu 18.04 with PG 12
    • static ip: 192.168.33.33
    • hostname: master
  • box2: slave -> Ubuntu 18.04 with PG 12
    • static ip: 192.168.33.44
    • hostname: slave

encoreshao

PostgreSQL 10 Master-Slave Replication on Virtualbox

Preparations

• Needs to download tools
  • Virtualbox
  • Vagrant
• Discover Vagrant Boxes - Linux
  • Ubuntu 18.04.4 LTS
• Two Vagrant boxes
• Master IP: 192.168.33.11 – read/write

encoreshao

-- show running queries (pre 9.2)
SELECT procpid, age(query_start, clock_timestamp()), usename, current_query 
FROM pg_stat_activity 
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' 
ORDER BY query_start desc;

-- show running queries (9.2)
SELECT pid, age(query_start, clock_timestamp()), usename, query 
FROM pg_stat_activity 
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' 

chmarr

SELECT blocked_locks.pid         AS blocked_pid,
       blocked_activity.usename  AS blocked_user,
	   now() - blocked_activity.query_start
		                         AS blocked_duration,
       blocking_locks.pid        AS blocking_pid,
       blocking_activity.usename AS blocking_user,
	   now() - blocking_activity.query_start
                                 AS blocking_duration,
       blocked_activity.query    AS blocked_statement,
       blocking_activity.query   AS blocking_statement

joeperrin-gists

function copyToClipboard( text ){
                var copyDiv = document.createElement('div');
                copyDiv.contentEditable = true;
                document.body.appendChild(copyDiv);
                copyDiv.innerHTML = text;
                copyDiv.unselectable = "off";
                copyDiv.focus();
                document.execCommand('SelectAll');
                document.execCommand("Copy", false, null);
                document.body.removeChild(copyDiv);

sj26

RSpec ExampleGroup extensions for CarrierWave

Infers as much as possible about uploader—the model class, what it's mounted as, etc—, sets up an uploader for specs, handles dis/enabling processing for only uploader specs, and makes it easy to describe behaviour of versions.

Drop it in spec/support/carrierwave.rb or something similar.

TODO: Microgem coming, can't get it all loading in the right order.

lpar

# Runs a specified shell command in a separate thread.
# If it exceeds the given timeout in seconds, kills it.
# Returns any output produced by the command (stdout or stderr) as a String.
# Uses Kernel.select to wait up to the tick length (in seconds) between 
# checks on the command's status
#
# If you've got a cleaner way of doing this, I'd be interested to see it.
# If you think you can do it with Ruby's Timeout module, think again.
def run_with_timeout(command, timeout, tick)
  output = ''