Work Breakdown Structure

Reference:  http://alvinalexander.com/fpa/cost-estimating/Estimating_using_Work_Break.shtml

Estimating using Work Breakdown Structure

Work Breakdown Structure (WBS) is probably how 98% of software development projects are estimated. WBS consists of someone sitting down and saying "Okay, how are we going to get this done?", then coming up with a long laundry list like this:

1. Setting up Development, Test, and Production environments - 8 hours
2. Creating the Login screen - 4 hours
3. Creating the Landing Page - 2 days
4. Developing the XYZ Page - 12 hours
5. etc., etc., etc.

You then continue with a long laundry list of every task you can imagine, with each task having an associated estimate. At the end you add up the time for all the tasks, and you have your overall time estimate.

Or do you?

WBS accuracy

As a practical matter, most WBS estimates I've seen under-estimate the total time required by a factor of 1.25 to 2.5. That is, if someone tells me that they did a WBS estimate and came up with 100 hours, the real answer is typically 125 to 250 hours.

IFPUG data also supports this. Though I don't have the exact data with me, I do remember that their data shows that estimates created using WBS alone under-estimate project effort by an average of about 50%. The reality is that this ratio actually varies quite a bit from person to person: some developers over-estimate, some under-estimate, some are very close. The good news is that people are consistent, and if they usually under-estimate by a factor of 2.5 they tend to always estimate by a similar ratio, unless ...

Use feedback to improve WBS estimates

If these developers are made to always review their estimates I believe they will eventually get better. For instance, let's say a developer told me a project would take 100 hours, but it really took 250 hours. After the project I would sit down with the developer and say "Okay, you estimated 100 hours, but it really took 250 hours. Now, I'm not here to beat you over the head. In fact, we like you quite a bit and want you on all of our future projects. But we need to take a little time and see where this estimate was off, okay?"

You do this behind closed doors, because everybody I know feels vulnerable when they're estimating. This stuff is hard, and it's not an exact science, I know that. But if you don't go through this process people won't get better.

Getting back to the WBS estimate, let's imagine that we worked through this process and we came up with an estimate of 1,600 hours. Given our team of four developers, this equates to 400 hours per developer. At 35 hours per week this is about 11.4 weeks of development effort.

Don't forget acceptance testing

Historically speaking, the people that I've seen take the WBS effort do not include final acceptance testing in their estimates, so I'll assume that's the case here. I'll use the same ratio of development time to final acceptance testing time that I used before (a 3:1 ratio), so if development takes 11.4 weeks, acceptance testing should take an additional 3.8 weeks (and the 1,600 hour estimate needs to be increased to 2,133 hours).

WBS estimate

Therefore, WBS predicts a total development time of 2,133 hours, or 15.2 weeks.

Jersey Maven setup Log4j2

1. In pom.xml, add:

<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.0.1</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.0.1</version>
</dependency>

2. Add log4j configuration file to path: src/main/webapp/WEB-INF/classes
(create the classes folder manually)

3. Code:

Logger logger = LogManager.getLogger();
logger.info("info!!!!!!!!!!!!!!");

Serialize Object to Json indented string with Jersey

1. pom.xml - Use Jackson
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-json-jackson</artifactId>
        </dependency>   

2. Code:

        ObjectMapper mapper = new ObjectMapper();
        mapper.enable(SerializationFeature.INDENT_OUTPUT);
        String rJson = "";
        try {
            rJson = mapper.writeValueAsString(request);
            System.out.println(rJson);
        } catch (JsonProcessingException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

Tomcat 7 connection pool with JNDI datasource and postgreSQL

1. Tomcat's content.xml

<Context>    <Resource name="jdbc/postgres" auth="Container"            type="javax.sql.DataSource" driverClassName="org.postgresql.Driver"            url="jdbc:postgresql://127.0.0.1:5432/mydb"            username="myuser" password="mypasswd" maxActive="20" maxIdle="10"  maxWait="-1"/>  </Context>

2. Web application's web.xml

<resource-ref>   <description>postgreSQL Datasource example</description>   <res-ref-name>jdbc/postgres</res-ref-name>   <res-type>javax.sql.DataSource</res-type>   <res-auth>Container</res-auth>  </resource-ref>

2. Code

    Connection conn = null;
        try {
            InitialContext cxt = new InitialContext();
            DataSource ds = (DataSource) cxt.lookup( "java:/comp/env/jdbc/postgres" );
            conn = ds.getConnection();
           
                 ...

                ...   
                while(rs.next()) {
                ...
                ...

                }
                rs.close();
            }
            conn.close();
        } catch (NamingException e1) {
            e1.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        };

Maven Postgresql JDBC

1. Add dependency in pom.xml. e.g.
http://mvnrepository.com/artifact/org.postgresql/postgresql/9.3-1100-jdbc41
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.3-1100-jdbc41</version>
</dependency>

2. Coding:

Connection conn = null;
try
{
Class.forName("org.postgresql.Driver");
String url = "jdbc:postgresql://THE_HOST/THE_DATABASE";
conn = DriverManager.getConnection(url,"THE_USER", "THE_PASSWORD");
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery("SELECT id, subject, permalink
FROM blogs ORDER BY id");
while ( rs.next() )
{
Blog blog = new Blog();
blog.id = rs.getInt ("id");
blog.subject = rs.getString ("subject");
blog.permalink = rs.getString ("permalink");
listOfBlogs.add(blog);
}
rs.close();
st.close();

}
catch (ClassNotFoundException e)
{
e.printStackTrace();
System.exit(1);
}
catch (SQLException e)
{
e.printStackTrace();
System.exit(2);
}

System server requirements

System hardware requirements
	CPU	File I/O	Database I/O	RAM
Management Web App	High	Low	High	Mid
Scoring Web App	Low	Low to Mid	Mid	Mid
Workers	High	High	Mid	High
PostgreSQL	Mid	High	N/A	High
DWH	N/A	N/A	High	N/A
ETL	High	Low to Mid	Mid	High
CRM	Mid	Low	Mid	Mid
Analytics Engine	High	Low	Mid	High
System Server Requirements
	File Server	Database Server	Web Server	Processing Server
Functionalities	SFTP, NFS	DWH, Operation DB	Web based application, CRM, …	Workers, ETL, Analysis Engine, …
CPU	Low (E3-1230v2 or existing)	Mid to High (E5-2420 dual / E52620 dual)	Mid (E3-1230v2/existing server)	High (E3-1230v2/existing server)
RAM	16G or above	32G or above	16G or above	16G or above
RAID	RAID 1/5/6	RAID 10	NO RAID / RAID 1	NO RAID
RAID Controller	Dell H710p or equivalent	Dell H710p or equivalent	N/A	N/A
HDD	TBD	1TB x 4	500GB	500GB
Quantity	x1	x1	xN	xN
Public IPs	x1	N/A	x2	N/A
Region	All	All	All	All
Scalability	Add drive for increase storage capacity.  Can add new server as required.	Single server can support up to 3 to 5 years.  Can add new server as required.	Scale Horizontally by adding new server as required.	Scale Horizontally by adding new server as required.
New Server Price	20K (Dell R220) to 40K (Dell R520)	50K+ HKD (Dell R520/R720)	12K HKD (Dell R220)	12K HKD (Dell R220)
Servers Allocation
Live site
	File Server	Database Server	Web Server	Processing Server
	New server Dell R220/R520	New server Dell R520/R720	HK
	20K/40K+ HKD - Stage 2+	50K+ HKD - Stage 2	existing server #1 - Management
		Support both all regions	existing server #2 - Scoring
		Database for Management, Scoring, Worker, DWH, etc.	Dell R210 - Workers, ETL, SFTP
			UK
			existing #3 - Management
			existing #4 - Scoring
	=R220, R210 #2 in Stage 1	= existing servers, R210 and R220 servers in Stage 1	Dell R220 #2 (12K HKD - Stage 1) - Worker, SFTP	=R210, R220 #2 in Stage 1
Standby site
	File Server	Database Server	Web Server	Processing Server
	New server Dell R220 RAID 1	New server Dell R220 with RAID 1	HK
	~20K HKD - Stage 3	(* Use low to mid-range standby server)	R220 #3 (12K HKD - Stage 1.5) - Management, Scoring, SFTP, …
		~20K HKD - Stage 3	1 x VM #1 (2K HKD - Stage 1.5) Worker
			UK
			R220 #3 (12K HKD - Stage 1.5) - Management, Scoring, SFTP, …
	=R220 #3, R220 #4, VM #1, VM #2 in Stage 1.5	=R220 #3, R220 #4, VM #1, VM #2 in Stage 1.5	1 x VM #2 (2K HKD - Stage 1.5) Worker	=VM #1, VM #2 in Stage 1.5

Linux, Ubuntu log files location

=> /var/log/daemon.log : Running services such as squid, ntpd and others
log message to this file

=> /var/log/dmesg : Linux kernel ring buffer log

=> /var/log/dpkg.log : All binary package log includes package
installation and other information

=> /var/log/faillog : User failed login log file

=> /var/log/kern.log : Kernel log file

=> /var/log/lpr.log : Printer log file

=> /var/log/mail.* : All mail server message log files

=> /var/log/mysql.* : MySQL server log file

=> /var/log/user.log : All userlevel logs

=> /var/log/xorg.0.log : X.org log file

=> /var/log/apache2/* : Apache web server log files directory

=> /var/log/lighttpd/* : Lighttpd web server log files directory

=> /var/log/fsck/* : fsck command log

=> /var/log/apport.log : Application crash report / log file

=> /var/log/messages : General log messages

=> /var/log/boot : System boot log

=> /var/log/debug : Debugging log messages

=> /var/log/auth.log : User login and authentication logs

Using pg_prove with pgTap

>psql -d my_database;
#> create extension pgtap;
>\q

>pg_prove -d my_database some_test_file.sql

install pg_prove for pgtap

https://github.com/theory/tap-parser-sourcehandler-pgtap

>sudo ./Build
>sudo ./Build installdeps
>sudo ./Build test
>sudo ./Build install

DONE

Postgresql test frame - pgTap

http://pgtap.org

Check Ubuntu ethernet interface speed.

>sudo ethtool eth0

Messaging tools - RabbitMQ

http://www.rabbitmq.com/

Measure the bandwidth between 2 servers

Computer A, B:
> sudo apt-get install iperf

Computer A:
> iperf -s

Computer B:
> iperf -c address_of_computer_A

Ubuntu Server reconfigure timezone

>date
>more /etc/timezone
>sudo dpkg-reconfigure tzdata
>sudo service cron stop
>sudo service cron start

Google Map simple marker

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
<meta charset="utf-8">
<title>Geocoding service</title>
<style>
html, body, #map-canvas {
height: 100%;
margin: 0px;
padding: 0px
}
#panel {
position: absolute;
top: 5px;
left: 50%;
margin-left: -180px;
z-index: 5;
background-color: #fff;
padding: 5px;
border: 1px solid #999;
}
</style>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp"></script>
<script
src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script>
var geocoder;
var map;
function initialize() {
geocoder = new google.maps.Geocoder();
var latlng = new google.maps.LatLng(-34.397, 150.644);
var mapOptions = {
zoom: 8,
center: latlng
}
map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
}

var address_array =
[
"Shop 3-5, G/F, Po Fung Building, 1-7 Hop Yick Road, Yuen Long ",
"Rm 401, 4/F, Sincere House, 83 Argyle Street, Mong Kok ",
"Shop M001, Long Ping Commercial Complex, Long Ping Estate, Yuen Long ",
"Shop G06, G/F, Spot, 48 Lung Sum Avenue, Shek Wu Hui, Sheung Shui ",
"Unit 3, 2/F, United Success Commercial Centre, 508 Jaffe Road, Causeway
Bay "

];


count = 0
function codeAddress() {
//var address = document.getElementById('address').value;
var address = address_array[count];
if(typeof(address) == 'undefined') {
alert("Map completed.");
clearInterval(intervalID);
return;
}
geocoder.geocode( { 'address': address}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
map.setCenter(results[0].geometry.location);
var marker = new google.maps.Marker({
map: map,
position: results[0].geometry.location
});
} else {
if (status == google.maps.GeocoderStatus.OVER_QUERY_LIMIT) {
//alert("OVER_QUERY_LIMIT, just press ok to continue :) ");
count--;
} else {
the_index = address.indexOf(',');
if(the_index > 0) {
address_array.push(address.substring(the_index + 1,
address.length));
}
//alert('Geocode was not successful for the following reason: '
+ status);
//var error_messages = $('#messages').html() + status + " --- "
+ address + "<br/>"
//$('#messages').html(error_messages);
}
}
});
count++;
}


google.maps.event.addDomListener(window, 'load', initialize);

$(document).ready(function() {
//var intervalID = window.setInterval(codeAddress(), 1000);
start_map();
});

</script>
<script>

var intervalID;

function start_map() {
intervalID = window.setInterval(function(){codeAddress()}, 1000);
}

</script>

</head>
<body>
<div id="panel">
<!--
<input id="address" type="textbox" value="Sydney, NSW">
<input type="button" value="Geocode" onclick="start_map()">
-->
</div>
<div id="map-canvas" ></div>
<div id="messages" style='font-family:arial;' >The following
addresses cannot be marked: <br/></div>
</body>
</html>

Rails - Make Delayed job work with Rspec in tests

Turn off the queuing and let delayed job to run:

Delayed::Worker.delay_jobs = false

Rails override Time.now to return Time.zone.now

In initializer, add this:


class << Time
alias :system_now :now
def now
ActiveSupport::TimeWithZone.new(self.system_now.utc, Time.zone)
end
end

Nagios create plugins

On monitoring host:

Create plugin in /usr/lib/nagios/plugins (in C/Perl/Script/etc)
Enable plugin by:
1. define comment in /etc/nagios-plugins/config/somefile.cfg
2. edit /etc/nagios/conf.d/localhost_nagios2.cfg

Restart:
sudo service nagios3 restart

Reviewed Ubuntu Server monitoring tools

Tried:
1. Nagios
2. Munin
3. Cacti
4. Zabbix

Turn out I like both Nagios and Zabbix.

Setup Nagios on Ubuntu 12.10

sudo apt-get update
sudo apt-get install nagios3 nagios-nrpe-plugin

If you have other web pages or apps running on the same server, the following information might be useful to separate Nagios as it's own Apache virtual host on a non-standard port (for example 43326 here).

Remove standard config and create Apache virtual host;

sudo cp /etc/apache2/conf.d/nagios.conf /etc/apache2/sites-available/nagio  s3  sudo rm /etc/apache2/conf.d/nagios.conf  sudo vi /etc/apache2/sites-available/nagios3  

To beginning of file add;

Listen 43326  <VirtualHost *:43326>      ServerAdmin webmaster@localhost      DocumentRoot /var/www/nagios3  

To the end of the file add;

</VirtualHost>  

Enable the new site;

sudo a2ensite nagios3  

If you run a firewall (UFW), open the port;

sudo ufw allow 43326  

Restart Apache

sudo service apache2 restart

Ubuntu OS upgrade

http://www.cyberciti.biz/faq/howto-upgrade-to-ubuntu-14-04-from-ubuntu-13-10-or-12-04/

Linux system monitoring

http://www.linuxscrew.com/2012/03/22/linux-monitoring-tools/
http://www.tecmint.com/command-line-tools-to-monitor-linux-performance/
http://www.cyberciti.biz/tips/top-linux-monitoring-tools.html
http://www.thegeekstuff.com/2011/12/linux-performance-monitoring-tools/
http://www.opensourceforu.com/2013/12/look-top-three-network-monitoring-tools/

Tutorial resources

http://techtalk4us.blogspot.hk/2012/10/the-big-list-of-free-programming.html

Rails: Specify Time.zone in delayed job

Add the following code to the project's config/initializers/delayed_job.rb

The method_missing chain will add the current Time.zone.name to the
function's argument.

The Time.zone.name will be popped by the PerformableMethod.perform chain.


Delayed::DelayProxy.class_eval do

# Embed the current time zone name to delayed job's arguments when
# adding delayed job from delay() method.
def method_missing_with_custom_time_zone(method, *args)
raise "Time zone is nil" if Time.zone.nil?
args << {:custom_time_zone => Time.zone.name}
result = method_missing_without_custom_time_zone(method, *args)
result
end
alias_method_chain :method_missing, :custom_time_zone

end

Delayed::PerformableMethod.class_eval do

# Read time zone from job's argument.
def perform_with_custom_time_zone
if self.args.last.is_a?(Hash) &&
!self.args.last[:custom_time_zone].nil?
Time.zone = args.pop[:custom_time_zone]
else
raise "Custom time zone is missing from the arguments."
end
perform_without_custom_time_zone
end
alias_method_chain :perform, :custom_time_zone

end

Rails test with method that invoke delayed job

class Klass
def some_function
self.delay.time_consuming_function
end

def time_consuming_function
...
end
end

class KlassTest

test "some_function" do
Delayed::Job.all.each { |job| job.destroy }
Klass.new.some_function
Delayed::Job.all.each { |job| job.invoke_job }

assert ...
end

end

Postgresql server config files location

/etc/postgresql/[version]/main/

e.g. to set the listened port or location
/etc/postgresql/9.3/main/postgresql.conf

Function point analysis

http://alvinalexander.com/FunctionPoints/

Single sign on for web applications

Trial on Atlassian Crowd

current application on
1. Ruby on rails - using devise gem
2. Java EE application.

to be cont....

Postgresql kill process

select * from pg_stat_activity;
select pg_cancel_backend([procpid]);

What if you revoke an SSL cert?

After revoke, client may see on firefox (may not be the case on Chrome):


To by-pass the checking in firefox, do this but not recommended:


Uncheck the checking option under validation button.

Change crontab default editor

>select-editor

Ubuntu boot startup time log graph

BootCharting: https://wiki.ubuntu.com/BootCharting

Toolbox - convert excel formula to asp.net

www.spreadsheetconverter.com

Check installed software on windows

wmic

wmic:root\cli>/output:C:\InstallList.txt product get name, version
wmic:root\cli>exit

Business Intelligence Tools - Jaspersoft

https://community.jaspersoft.com/download

Ubuntu: Change the waiting time on network configuration

/etc/init/failsafe.conf

IT Director Responsibilities and Duties

IT Director Responsibilities and Duties


Coordinate with management in developing business strategic plans and operating policies.

Coordinate with business teams to analyze project contracts, proposals, requirements, and service level agreements.

Assist in developing project budgets and timelines.

Utilize project management experience to lead various global and regional projects.

Evaluate and revise project plan to meet changing project demands.

Manage project planning, staffing, schedule and expenses.

Oversee everyday project operations to ensure timely delivery.

Oversee the availability of application and infrastructure for project execution.

Identify and assign resources to IT projects.

Organize project status meetings with customers and team members.

Interact with customers to design and execute business solutions.

Ensure project deliverables meet highest quality standards and customer requirements.

Develop departmental standards and ensure that staffs adhere to these standards.

Provide analytical and technical assistance to project team.

Collaborate with management on application development, enhancement, and deployment activities.

Evaluate project proposals and change requests and make necessary recommendations for approval or rejection of proposals.

Revisit OOP fundumentals

Inheritance
Polymorphism
Abstraction
Encapsulation

Rails - Define class method in module file

module PicturePartials
module Cse

def self.included(base)
base.extend ClassMethods
end

module ClassMethods
def find_by_picture_id(picture_id)
Picture.joins(:picture).where('picture_id = ?', picture_id).first
end
end


end
end

Ubuntu upgrade postgresql server from 8.4 to 9.2

• backup database: pg_dumpall > dump.sql
• http://wiki.postgresql.org/wiki/Apt
• Create /etc/apt/sources.list.d/pgdg.list
• Put this in the file:
• deb http://apt.postgresql.org/pub/repos/apt/ [code]-pgdg main
• where [code] can be found by lsb_release -c
• wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
• sudo apt-get update
  
• ps -C postgres
  
• sudo apt-get purge postgresql-8.4
• Create database user
• Restore database
  
• Done
  

Restart network interface

sudo /etc/init.d/networking restart

Ubuntu find versions

uname -a (for kernel version)

lsb_release -a (for ubuntu version)

sudo fdisk -l (for partition info)

BI qlikview

www.qlik.com

Ubuntu start Tomcat on boot

Automatic Starting

To make tomcat automatically start when we boot up the computer, you can
add a script to make it auto-start and shutdown.

sudo vi /etc/init.d/tomcat

Now paste the following content:

# Tomcat auto-start
#
# description: Auto-starts tomcat
# processname: tomcat
# pidfile: /var/run/tomcat.pid

export JAVA_HOME=/usr/lib/jvm/java-6-sun

case $1 in
start)
sh /usr/local/tomcat/bin/startup.sh
;;
stop)
sh /usr/local/tomcat/bin/shutdown.sh
;;
restart)
sh /usr/local/tomcat/bin/shutdown.sh
sh /usr/local/tomcat/bin/startup.sh
;;
esac
exit 0
You'll need to make the script executable by running the chmod command:

sudo chmod 755 /etc/init.d/tomcat

The last step is actually linking this script to the startup folders
with a symbolic link. Execute these two commands and we should be on our
way.

sudo ln -s /etc/init.d/tomcat /etc/rc1.d/K99tomcat

sudo ln -s /etc/init.d/tomcat /etc/rc2.d/S99tomcat

Install webmin on Ubuntu

1. Download from http://www.webmin.com
2. sudo dpkg -i webmin_x.xxxx_all.deb  (with error)
3. sudo apt-get install -f (will fix the error)
4. https://xxx.xxx:1000
DONE

diagnostic cap deploy permission denied public key

Problem:

xxxxx@xxxxx:~/RubyProjects/xxxxx$ bundle exec cap xxxxx deploy:migrations
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.1.4/lib/bundler/runtime.rb:211: warning: Insecure world writable dir /usr/local/rvm/gems in PATH, mode 042777
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.1.4/lib/bundler/runtime.rb:211: warning: Insecure world writable dir /usr/local/rvm/gems in PATH, mode 042777
  * executing `xxxxx'
    triggering start callbacks for `deploy:migrations'
  * executing `multistage:ensure'
  * executing `eighties_bands:ensure'
  * executing `deploy:migrations'
  * executing `deploy:update_code'
    updating the cached checkout on all servers
    executing locally: "git ls-remote git@xxxxx.unfuddle.com:xxx/xxxxx.git xxxxx-4"
    command finished in 4746ms
  * executing "if [ -d /home/xxxxx/deploy/shared/cached-copy ]; then cd /home/xxxxx/deploy/shared/cached-copy && git fetch -q origin && git reset -q --hard b40a43e351c2107de5c6bc8dae0c70de86465305 && git clean -q -d -x -f; else git clone -q  git@xxx.unfuddle.com:xxx/xxxxx.git /home/xxxxx/deploy/shared/cached-copy && cd /home/xxxxx/deploy/shared/cached-copy && git checkout -q -b deploy b40a43e351c2107de5c6bc8dae0c70de86465305; fi"
    servers: ["115.160.152.28"]
    [115.160.152.28] executing command
 ** [115.160.152.28 :: err] Permission denied (publickey).
 ** [115.160.152.28 :: err] fatal: The remote end hung up unexpectedly
    command finished in 13024ms
failed: "sh -c 'if [ -d /home/xxxxx/deploy/shared/cached-copy ]; then cd /home/xxxxx/deploy/shared/cached-copy && git fetch -q origin && git reset -q --hard b40a43e351c2107de5c6bc8dae0c70de86465305 && git clean -q -d -x -f; else git clone -q  git@xxx.unfuddle.com:xxx/xxxxx.git /home/xxxxx/deploy/shared/cached-copy && cd /home/xxxxx/deploy/shared/cached-copy && git checkout -q -b deploy b40a43e351c2107de5c6bc8dae0c70de86465305; fi'" on 115.160.152.28

Reason:
  git login failed on target machine.

Checkings:
ssh -v git@xxx.unfuddle.com

• Check this on deployment machine and target server
• If success, should see this: Authentication succeded (publickey).
• If denied, will see this: debug1: Authentications that can continue: publickey
  • This means the connection to git server is denied.

Solution:
On deployment machine,

• ForwardAgent yes (.ssh/config)
• Check if ssh-agent is running
• ps aux | grep ssh
• Add key to ssh:
• ssh-add ~/.ssh/id_rsa
• Check key:
• ssh-add -l
• Done

Ruby Json Indent Format

JSON.pretty_generate()

Change ubuntu apt-get mirror site

sudo vi /etc/apt/sources.list

deb http://ftp.cuhk.edu.hk/pub/Linux/ubuntu precise main restricted
universe multiverse
deb-src http://ftp.cuhk.edu.hk/pub/Linux/ubuntu precise main restricted
universe multiverse

deb http://ftp.cuhk.edu.hk/pub/Linux/ubuntu precise-updates main
restricted universe multiverse
deb-src http://ftp.cuhk.edu.hk/pub/Linux/ubuntu precise-updates main
restricted universe multiverse

:wq

sudo apt-get update

(e.g.) sudo apt-get install maven

Allow remote access to postgres sql

edit /etc/postgresql/9.1/main/postgresql.conf

listen_address = '*'

edit /etc/postgresql/9.1/main/pg_hba.conf

replace the config with:

host all all 0.0.0.0/0 md5

Check 32 bit or 64 bit Ubuntu version

uname -a

Result for 32-bit Ubuntu:

Linux discworld 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:50 UTC
2011 i686 i686 i386 GNU/Linux

whereas the 64-bit Ubuntu will show:

Linux discworld 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:50 UTC
2011 x86_64 x86_64 x86_64 GNU/Linux

Revisit Java deadlock

Java deadlock:
http://javarevisited.blogspot.hk/2010/10/what-is-deadlock-in-java-how-to-fix-it.html

Backup postgresql using pgdump

>sudo su - postgres
>pg_dump some_database_name > somename.sql

Ubuntu bash check opened port

sudo netstat -anltp

Wireframe tool

http://balsamiq.com/

Technical - Mulesoft ESB vs Talend

http://www.slideshare.net/KaiWaehner/spoilt-for-choice-how-to-choose-the

Mysql dump backup and restore all database

Backup:

  mysqldump --flush-privileges --all-database -p > mysqldump.all.database.20130723.sql


Restore:

  mysql -u root -p < mysqldump.all.database.20130723.sql

Solved: apt-get install 404 Not Found

sudo apt-get update

Solve: apache You don't have permission to access / on this server

In httpd.conf

<Directory />
    #Options FollowSymLinks
    Options Indexes FollowSymLinks Includes ExecCGI
    AllowOverride All
    Order deny,allow
    Allow from all
</Directory>

EaseUS - windows partition tools

http://www.easeus.com/

Ubuntu change name/ hostname

# vim /etc/hostname
內容改為自己要的名字

# vim /etc/hosts
這邊最好也要改，免得有些 service 會出錯

# /etc/init.d/hostname.sh or # sudo service hostname restart
重新啟動

# hostname
驗證是否已經修改完畢。

postgresql create drop user

Postgresql server start

Use the following command (from terminal) to control the PostgreSQL server
Start the service : /etc/init.d/postgresql start
Stop the service : /etc/init.d/postgresql stop
Know the status : /etc/init.d/postgresql status
Restart the service : /etc/init.d/postgresql restart

Read more: http://linuxpoison.blogspot.tw/2012/01/how-to-install-configure-postgresql.html#ixzz2RutcjeNH

ubuntu fix ip

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

File: /etc/network/interfaces

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static


address 192.168.8.188
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.225
gateway 192.168.8.1
dns-nameservers 192.168.8.201 202.130.97.65

sudo /etc/init.d/networking restart

mac hosts file

sudo vi /private/etc/hosts

Install apache for ruby on rails on Ubuntu

1. Install apache2
1. sudo apt-get update
   
2. sudo apt-get install apache2
2. Enable https
1. sudo a2enmod ssl
   sudo a2ensite default-ssl
   
   sudo service apache2 restart
3. Install Passenger
1. gem install passenger
2. passenger-install-apache2-module
3. sudo apt-get install libcurl4-openssl-dev
4. rvmsudo rvm get head && rvm reload && rvm repair all
5. Permission denied -> chmod 777...
   

Install passenger on ubuntu

Ubuntu: Curl development headers with SSL support

By: Richard26-11-2010computing
Share
Just been trying to install Passenger on a new Ubuntu EC2 instance and
passenger is giving me the error:


* Curl development headers with SSL support... not found


Took some digging around but turns out I was just missing the
libcurl4-openssl-dev package:


sudo apt-get install libcurl4-openssl-dev

Solve Apache2 permission problem.

<Directory />
    Options FollowSymLinks
    AllowOverride All
    Order deny,allow
    Allow from all
</Directory>

vim binary mode

To binary mode -- :%!xxd
To normal mode -- :%!xxd -r

Git move master to branch

git checkout target_branch
git merge --strategy==ours --no-commit master
git commit -m "Move master to this branch..."
git checkout master
git merge target_branch

Git command history

>git reflog

Linux - Bash encrypt and decrypt file

openssl des3 -salt -in unencrypted-data.file \
-out encrypted-data.file.des3

openssl des3 -d -salt -in encrypted-data.file.des3 \
-out unencrypted-data.file

Mysql - backup all databases

$ mysqldump -u root -p --all-databases > alldb_backup.sql

Migrate Atlassian Confluence local version 4.0 to OnDemand version 5.0

1. Backup current wiki data to XML.
2. Upgrade local 4.0 to 5.0 version.
3. Subscribe Confluence OnDemand service.
4. Export space from local wiki, one by one, since OnDemand version cannot restore the whole backup in one click.
5. Import spaces to OnDemand.
6. Done.
   

Mac reset password

1. Press and Hold Command-R when startup.
2. Open terminal.
3. >resetpassword

Windows 7 hosts file

C:\Windows\System32\driven\etc\hosts

Git - remove or delete tag and remote tag

git tag -d 12345  git push origin :refs/tags/12345

Rails - update attr_readonly field from sql

The easiest way to update field with attr_readonly is to update by
database sql.

$> psql -d xxx -U xxx
xxx> update ... set ... where ...