cwegener

SQL Server Performance Tuning Class - Day 2

Denver 2015

Finding Queries and Bottlenecks

RECOMPILE hints will cause the sproc to not show up in the DMV (Dynamic Management Views)
DMVs and profiler will only catch perf issues for a window of time. They are passive tools that have to be running when the issue occurs
sp_Blitz will look across a wider window of time.
ClearTrace as scriptable (and more powerful) version of SQL Server Profiler.
Recommended practice is to create a Tools database to store scripts like ClearTrace and the BrentOzar scripts. May shops will not allow anything to be installed to master. Plus, master won't be restored typically during a rebuild

Usage

(Create a symlink pytest for py.test)

pytest [options] [file_or_dir] [file_or_dir] ...

Help:

My Elasticsearch cheatsheet with example usage via rest api (still a work-in-progress)

Shortlinks:

Cluster Health
- Index Level
- Shard Level
Nodes Overview
Indices Overview
Cluster Maintenance

Linting your code, the vanilla way

You may want a linter plugin to lint your code in Vim but you probably don't need it. At least try the built-in way before jumping on the plugin bandwagon.

Defining `makeprg`

autocmd FileType <filetype> setlocal makeprg=<external command>

This autocommand tells Vim to use <external command> when invoking :make % in a <filetype> buffer. You can add as many similar lines as needed for other languages.

Goal

How to launch multiple QEMU based VM's that can communicate with the outside world and between each other other without any setup on the host.

This uses two features available in qemu

User Mode Networking stack - SLIRP
Socket networking backend allows you to create a network of guests that can see each other

This allows us to have

	// Parsing arbitrary JSON using interfaces in Go
	// Demonstrates how to parse JSON with abritrary key names
	// See https://blog.golang.org/json-and-go for more info on generic JSON parsing

	package main

	import (
	"encoding/json"
	"fmt"
	)

	function Set-ExitCodeAndExit {
	[CmdletBinding(SupportsShouldProcess=$True,DefaultParameterSetName="None")]
	PARAM(
	[Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true, ParameterSetName="p1")]
	[int]
	$ExitCode
	)
	Write-Verbose "Setting ExitCode to $($ExitCode) and exiting..."
	# When a PowerShell script is called from a batch file or Command Prompt, this line allows a return code back to the calling shell
	$host.SetShouldExit($ExitCode)

	#
	# INPUT - Logstash listens on port 8514 for these logs.
	#

	input {
	udp {
	port => "8514"
	type => "syslog-cisco"
	}

	# This is an example Makefile for quick package creation
	#
	# It uses FPM [1] to generate simple packages.
	# - If you need more features or a greater quality package, use debian
	# standard tools for packaging.
	# - Do not use checkinstall. Use FPM instead.
	#
	# [1] (https://github.com/jordansissel/fpm/wiki)

	# IMPORTANT:

	---
	# Original idea found at http://stackoverflow.com/a/39083724
	#
	# ansible -i inventory.ini add-ssh-keys.yml
	#
	- name: Store known hosts of 'all' the hosts in the inventory file
	hosts: localhost
	connection: local
	vars:
	ssh_known_hosts_command: "ssh-keyscan -T 10"