SQL Training - Fundamental I

1. Introduction

This post gathers information about SQL Training, abording fundamental questions.

2. References

• https://github.com/josemarsilva/treina-sql-I/wiki

How to Use Windows 8 Performance Monitor to Analyse Your System Performance

1. Introduction

This post shows step-by-step how to configure Windows environment to collect performance counters.

2. Step by Step

2.1. Before Starting 

Performance tunning process is a cycle process. Maybe you don't find your major bootleneck on the first time, so you will need to iterate and refine performance counters until find it.

2.1. How to have a Quick Wins of performance

• Run Task Manager (taskmgr) 

2.2. How to configure Windows Performance Monitor to Analyze your System Performance

3. References

• http://technet.microsoft.com/en-us/library/bb490958.aspx
• http://blogs.technet.com/b/askperf/archive/2008/05/20/two-minute-drill-relog-exe.aspx
• http://www.maketecheasier.com/windows-8-performance-monitor-to-analyse-system/
• http://www.computerperformance.co.uk/win8/windows8-performance-monitor.htm

Install Nexus on Ubuntu 16.04

1. Introduction

This post shows how to install Nexus on Ubuntu 16.04

2. Step by Step

2.1. Download install binary

$ cd /tmp
$ wget http://download.sonatype.com/nexus/3/nexus-3.6.0-02-unix.tar.gz

2.2. Install Nexus on /opt/nexus

$ tar -xvzf nexus-3.6.0-02-unix.tar.gz

$ sudo mv /tmp/nexus-3.6.0-02 /opt

$ sudo mv /opt/nexus-3.6.0-02 /opt/nexus

2.3. Configure Nexus 

a) Configure Nexus Port

$ sudo cp /opt/nexus/etc/nexus-default.properties /opt/nexus/etc/nexus-default.properties.bkp.2017-11-05 # take a backup

$ sudo vim /opt/nexus/etc/nexus-default.properties
    :
application-port=8081
    :

b) Add firewall rule to accept incomming call on nexus port 8081

$ sudo ufw allow 8081

c) Configure Nexus script - run_as_user

$ sudo cp /opt/nexus/bin/nexus /opt/nexus/bin/nexus.bkp.2017-11-05 # backup
$ sudo vim /opt/nexus/bin/nexus
    :
# user to execute as; optional but recommended to set
run_as_user='nexus'
NEXUS_HOME="/opt/nexus"
    :

d) Configure nexus users and group

$ sudo adduser --no-create-home --disabled-login --disabled-password nexus
Adding user `nexus' ...
Adding new group `nexus' (1002) ...
Adding new user `nexus' (1002) with group `nexus' ...
Not creating home directory `/home/nexus'.
Changing the user information for nexus
    :
Is the information correct? [Y/n] Y

e) Set files permission '/opt/nexus'

$ sudo chown -R nexus:nexus /opt/nexus

2.4. Deploying nexus and sonatype-work directories

$ sudo mkdir /var/lib/nexus

$ sudo mkdir /var/lib/nexus/sonatype-work

$ sudo chown -R nexus:nexus /var/lib/nexus

2.5. Run Nexus and check

$ su - nexus
$ whoami
nexus
$ /opt/nexus/bin/nexus start

3. References

• https://www.build-business-websites.co.uk/install-nexus-on-ubuntu-16-04/

Installing Tomcat 8 on Ubuntu Server 16.04

1. Introduction

This post shows step by step how to install Tomcat into Ubuntu Server 16.04.

2. Step-by-Step

2.1. Update system packages

$ sudo apt-get update

2.2 Create Tomcat User and Group

a)  Create 'tomcat' Group

$ sudo groupadd tomcat

b) Create 'tomcat' Group

$ sudo useradd -s /bin/false -g tomcat -d /opt/tomcat tomcat

2.3 Download Tomcat installer from mirror site

a) Open Tomcat mirror site in your browser and find out current available download version

+---------------------------------------------------------------------------------+

| http://apache.mirrors.ionfish.org/tomcat/tomcat-8/                              |

+---------------------------------------------------------------------------------+

| Index of /tomcat/tomcat-8                                                       |

|                                                                                 |

| Name                    Last modified      Size  Description                    |

| ../                                          -                                  |

| v8.0.47/                03-Oct-2017 08:50    -                                  |

| v8.5.23/                01-Oct-2017 18:31    -                                  |

|                                                                                 |

| Apache Server at apache.mirrors.ionfish.org Port 80                             |

+---------------------------------------------------------------------------------+

2.4 Download Tomcat install tar.gz for linux

$ cd /tmp

$ curl -O http://apache.mirrors.ionfish.org/tomcat/tomcat-8/v8.5.23/bin/apache-tomcat-8.5.23.tar.gz

2.5. Install Tomcat 8 into /opt/tomcat

a) Unzipping into /opt/tomcat

$ sudo mkdir /opt/tomcat
$ sudo tar xzvf apache-tomcat-8*tar.gz -C /opt/tomcat --strip-components=1

b) Adjusting permisson for 'tomcat' user

$ cd /opt/tomcat
$ sudo chgrp -R tomcat /opt/tomcat

$ sudo chmod -R g+r conf

$ sudo chmod g+x conf

$ sudo chown -R tomcat webapps/ work/ temp/ logs/

2.6. Create a systemd Service file for Tomcat

a) Checking JAVA_HOME

$ sudo update-java-alternatives -l
java-1.8.0-openjdk-amd64       1081       /usr/lib/jvm/java-1.8.0-openjdk-amd64

b) Create systemd service file on /etc/systemd/system/tomcat

$ sudo vim /etc/systemd/system/tomcat.service

[Unit]

Description=Apache Tomcat Web Application Container

After=network.target

[Service]

Type=forking

Environment=JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-amd64

Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid

Environment=CATALINA_HOME=/opt/tomcat

Environment=CATALINA_BASE=/opt/tomcat

Environment='CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC'

Environment='JAVA_OPTS=-Djava.awt.headless=true -Djava.security.egd=file:/dev/./urandom'

ExecStart=/opt/tomcat/bin/startup.sh

ExecStop=/opt/tomcat/bin/shutdown.sh

User=tomcat

Group=tomcat

UMask=0007

RestartSec=10

Restart=always

[Install]

WantedBy=multi-user.target

c) Reload systemd service to apply change

$ sudo systemctl daemon-reload

$ sudo systemctl start tomcat

d) Configure tomcat service to automatically starts on boot

$ sudo systemctl enable tomcat

e) Manually starting, stopping and status

$ sudo /opt/tomcat/bin/catalina.sh start
$ sudo /opt/tomcat/bin/catalina.sh stop
$ sudo /opt/tomcat/bin/catalina.sh status

2.7. Ajust firewall rule

a) Checking if

$ service ufw status
   ufw.service - Uncomplicated firewall
   Loaded: loaded (/lib/systemd/system/ufw.service; enabled; vendor preset: enab
   Active: active (exited) since Sun 2017-11-05 19:17:17 BRST; 12min ago
   Process: 376 ExecStart=/lib/ufw/ufw-init start quiet (code=exited, status=0/SU
   :

b) Add firewall rule to accept incomming call on Tomcat port 8080

$ sudo ufw allow 8080

2.8. Configure Tomcat Web Management Interface

a) Edit tomcat-users.xml, be carefull with remarks "<!--" "--->"

$ sudo vim  /opt/tomcat/conf/tomcat-users.xml
        :
<tomcat-users xmlns="http://tomcat.apache.org/xml"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="http://tomcat.apache.org/xml tomcat-users.xsd"
              version="1.0">

        :
  <user username="admin" password="admin" roles="manager-gui,admin-gui,tomcat"/>

        :
</tomcat-users>

        :

b) Edit context.xml, 

$ sudo vim /opt/tomcat/webapps/host-manager/META-INF/context.xml
     :
<Context antiResourceLocking="false" privileged="true" >
  <Valve className="org.apache.catalina.valves.RemoteAddrValve"
         allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1" />
  <Manager sessionAttributeValueClassNameFilter="java\.lang\.(?:Boolean|Integer|Long|Number|String)|org\.apache\.catalina\.filters\.CsrfPreventionFilter\$LruCache(?:\$1)?|java\.util\.(?:Linked)?HashMap"/>
</Context>

2.9. Open Tomcat in browser

a) Open default Tomcat page

• http://localhost:8080

b) Open Tomcat Documentation page

• http://127.0.0.1:8080/docs/

3. References

• https://www.digitalocean.com/community/tutorials/how-to-install-apache-tomcat-8-on-ubuntu-16-04
• https://www.digitalocean.com/community/tutorials/como-instalar-o-java-no-ubuntu-com-apt-get-pt

Installing OpenJDK (8 default for Ubuntu 16.04)

1. Introduction

This  post shows how to install Open JDK 8 default for Ubuntu 16.04.

2. Step By Step

2.1. Update package list

$ sudo apt-get update

2.2. Install Java JDK 8 default

$ sudo apt-get install default-jdk

2.3. Testing Java Compiler 

$ javac -version

3. References

• https://www.digitalocean.com/community/tutorials/como-instalar-o-java-no-ubuntu-com-apt-get-pt
• http://openjdk.java.net/

Install Jenkins on Ubuntu 16.04

1. Introduction

2. Step by Step

2.1. Prerequisites

2.1.a. Check Memory available

• 1 GB of RAM minimum; 
• 4 GB desired;

2.1.b. System Update

$ sudo apt-get update

2.2. Install Jenkins

$ wget -q -O - https://pkg.jenkins.io/debian/jenkins-ci.org.key | sudo apt-key add -
OK
$ cat /etc/apt/sources.list.d/jenkins.list
deb http://pkg.jenkins.io/debian-stable binary/
$ sudo apt-get update

2.3. Upgrade Jenkins version ( optional )

$ sudo apt-get update
$ sudo apt-get install jenkins

2.4. Cheking services

$ # Ubuntu/Debian (different from CentOs/Fedora) usually starts software after installation
$ # Jenkins will be started as a deamon service named 'jenkins'
$ # See /etc/init.d/jenkins for more details. Log file will be placed in /var/log/jenkins/jenkins.log.
$ # Config parameters like JENKINS_HOME and etc, will be captured on /etc/default/jenkins
$ # By default, Jenkins listen on port 8080. Edit /etc/default/jenkins to change port
$ # To start-stop-status service do: sudo service jenkins stop; sudo service jenkins start; sudo service jenkins status

2.5. Check/allow firewall rules

a) Check firewall status - Inactive? Great nothing to do

$ sudo ufw status
Status: inactive

b) Check firewall status - Active? add rule to allows Jenkins port

$ sudo ufw status
Status: active
:
8080                       ALLOW       Anywhere
:
$ sudo ufw allow 8080

2.6. Setting up Jenkins 

a) Access Jenkins interface on browser and you'll see "Unlock Jenkins screen"

• http://localhost:8080

$ sudo cat /var/lib/jenkins/secrets/initialAdminPassword

+------------------------------------------------+
| Unlock Jenkins                                 |
|    :       :                                   |
| /var/lib/jenkins/secrets/initialAdminPassword  |
| Administrator password                         | 
| [                   ]                          | <- paste here
+------------------------------------------------+

b) Install suggested plugins 

+------------------------------------------------+
| Customize Jenkins                              |
| +------------------+                           |
| |Install Suggested |                           |
| | Pluggins         |                           | <- click button
| +------------------+                           |
+------------------------------------------------+

c) Create first admin user

+------------------------------------------------+
| Create first admin user                        |
|   Username: [admin]                            |
|   Password: [admin]                            |
+------------------------------------------------+

3. References

• https://wiki.jenkins.io/display/JENKINS/Installing+Jenkins+on+Ubuntu
• https://www.digitalocean.com/community/tutorials/how-to-install-jenkins-on-ubuntu-16-04
• https://vexxhost.com/resources/tutorials/how-to-install-configure-and-use-jenkins-on-ubuntu-14-04/

Manipulating text files on linux

1. Introdução

This post gathers information about how to manipulates text files on linux systems.

2. Referências

• http://terminalroot.com.br/2015/07/30-exemplos-do-comando-sed-com-regex.html