FlorianHeigl

#!/bin/bash

. /tmp/context.sh

CONFIG_FILE="/etc/hostname"

function set_hostname() {
    NAME=$1

    [ -n "$NAME" ] || exit 0

FlorianHeigl

Rudder Inventory Flow


Managed Node:

rudder agent inventory
	cf-agent -KI -Dforce_inventory

FlorianHeigl

#cloud-config

# Set up the package repository to get Rudder.
# We use the "latest" pseudo-version name to always get an up-to-date agent.

write_files:
- content: |
        [Rudder_4.1]
        name=Rudder 4.1 EL repository
        baseurl=http://www.rudder-project.org/rpm-4.1/RHEL_7/

FlorianHeigl

my take on the gitlab issue

It happens I had read the database troubleshooting part of Gitlab's Ops manual (https://gitlab.com/gitlab-com/runbooks/blob/master/troubleshooting/postgresql_replication.md) just a month ago, looking for monitoring info. I found many sound instructions on how to deal with database replication issues. I was very happy when I read they're also using Check_MK, but ...

It also made me decide pg_basebackup is too dangerous w/o dedicated DBA staff for two reasons:

• reason 1: lack of stability / fault tolerance
• reason 2: destructive resume on issue

FlorianHeigl

#!/bin/bash -u

# Script to automate the setup and conversion of cache pools in LVM.
# I changed all my busy LVs using it, worked well for me.
# Cache and/or thin pools are supported since RHEL 6.4-ish but it's
# more complex/powerful than i.e. bcache. 
# They might be the best tool for you, or might as well not.

# this is as an example, you need to review the script.
# i've also only done basic tests of the error handlers below.

FlorianHeigl

#!/bin/bash -e
# $Id: dm-cache-status,v 1.1 2014/08/19 09:02:46 oernii Exp $

# Status
#  ------
#
#  <metadata block size> <#used metadata blocks>/<#total metadata blocks>
#  <cache block size> <#used cache blocks>/<#total cache blocks>
#  <#read hits> <#read misses> <#write hits> <#write misses>
#  <#demotions> <#promotions> <#dirty> <#features> <features>*

FlorianHeigl

http://www.smartbrief.com/original/2017/04/fallacy-lessons-learned?utm_source=brief

http://www.opsreportcard.com/

http://sts.ono.at/blog/2012/02/01/a-systems-policy/

https://zwischenzugs.wordpress.com/2017/04/04/things-i-learned-managing-site-reliability-for-some-of-the-worlds-busiest-gambling-sites/

SRE Book comments:

FlorianHeigl

#cloud-config

# Set up the package repository to get Rudder.
# We use the "latest" pseudo-version name to always get an up-to-date agent.

write_files:
- content: |
        [Rudder_4.1]
        name=Rudder 4.1 EL repository
        baseurl=http://www.rudder-project.org/rpm-4.1/RHEL_7/

FlorianHeigl

#cloud-config

# I'm very unhappy to end up with this scriptlike solution but there was some bugs (i.e. things not being run)
# that seem to be in their cloud-config version
runcmd:
  - apt-get -y install wget --force-yes
  - wget --quiet -O- "https://www.rudder-project.org/apt-repos/rudder_apt_key.pub" | apt-key add -
  - echo "deb http://www.rudder-project.org/apt-4.1/ $(lsb_release -cs) main" > /etc/apt/sources.list.d/rudder.list
  - apt-get update
  - DEBIAN_FRONTEND=noninteractive apt-get -y install rudder-agent --force-yes

FlorianHeigl

Yum basic tunables

yum.conf

tune the metadata expiry or rather turn it off and use cron to keep it updated out of band

yum makecache / cron

yum makecache fast