Requirements

Install Java JRE

First, install the latest Java Runtime Environment or JDK (tested with v1.6.0.65).

WARNING

In order to avoid any troubles while using Elastic Search, make sure that every node in the cluster uses the same JRE (or JDK) version.

Elastic Search requires at least Java v6 in order to run.

Ensure your JAVA_HOME environment variable is correctly set.

$ type java
  java is /usr/bin/java

$ java -version
  java version "1.6.0_65"
  Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609)
  Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-462, mixed mode)

Install Elastic Search

Elastic Search is the default backend search engine for WSE.

The most stable Elastic Search version tested on production is v0.90.10.

You can easily install it by (adapt for your OS):

$ wget https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-0.90.10.tar.gz
$ tar xvf elasticsearch-0.90.10.tar.gz
$ cd elasticsearch-0.90.10

Then test it in "console mode":

$ ./bin/elasticsearch -f
[2014-05-26 22:38:18,032][INFO ][node                     ] [Lorelei II] version[0.90.10], pid[30583], build[0a5781f/2014-01-10T10:18:37Z]
[2014-05-26 22:38:18,032][INFO ][node                     ] [Lorelei II] initializing ...
[2014-05-26 22:38:18,036][INFO ][plugins                  ] [Lorelei II] loaded [], sites []
[2014-05-26 22:38:19,510][INFO ][node                     ] [Lorelei II] initialized
[2014-05-26 22:38:19,510][INFO ][node                     ] [Lorelei II] starting ...
[2014-05-26 22:38:19,570][INFO ][transport                ] [Lorelei II] bound_address {inet[/0:0:0:0:0:0:0:0%0:9300]}, publish_address {inet[/192.168.1.105:9300]}
[2014-05-26 22:38:22,608][INFO ][cluster.service          ] [Lorelei II] new_master [Lorelei II][AI2ywI6KQBOv8y8yC8R2pw][inet[/192.168.1.105:9300]], reason: zen-disco-join (elected_as_master)
[2014-05-26 22:38:22,631][INFO ][discovery                ] [Lorelei II] elasticsearch/AI2ywI6KQBOv8y8yC8R2pw
[2014-05-26 22:38:22,643][INFO ][http                     ] [Lorelei II] bound_address {inet[/0:0:0:0:0:0:0:0%0:9200]}, publish_address {inet[/192.168.1.105:9200]}
[2014-05-26 22:38:22,644][INFO ][node                     ] [Lorelei II] started
[2014-05-26 22:38:22,656][INFO ][gateway                  ] [Lorelei II] recovered [0] indices into cluster_state

Hit CLTR+C to quit.

For this example, we’ll create 02 Elastic Search nodes to form our initial cluster.

Edit “config/elasticsearch.yml” to read this:

################################### Cluster ###################################

# Cluster name identifies your cluster for auto-discovery. If you're running
# multiple clusters on the same network, make sure you're using unique names.
#
cluster.name: wse_cluster

...

# Set the number of replicas (additional copies) of an index (1 by default):
#
index.number_of_replicas: 1

Install the following plugins

> The "attachment" plugin (mandatory)

$ elasticsearch-0.90.10
$ bin/plugin -install elasticsearch/elasticsearch-mapper-attachments/1.9.0

> The "Head" plugin (optional)

$ cd elasticsearch-0.90.10
$ bin/plugin -install mobz/elasticsearch-head

> List the installed plugins:

$ ./bin/plugin --list
  Installed plugins:
   - head
   - mapper-attachments

Creates the 2-nodes Elastic Search cluster:

$ cp -rf elasticsearch-0.90.10 es1
$ cp -rf elasticsearch-0.90.10 es2

Then, start the cluster:

$ cd es1
$ ./bin/elasticsearch

$ cd ../es2
$ ./bin/elasticsearch

Point your browser to:

http://127.0.0.1:9200/_plugin/head/

Install Erlang

Second, the Erlang programming language needs to be installed.

WSE requires Erlang version R15B01 (recommended) or above.

Windows

Depending on your architecture (32/64-bit), download the right binary for Windows at:

http://www.erlang.org/download.html

Then, follow the standard install procedure using the wizzard.

Step 1/4

Install wizard for Windows

Please, make sure the Microsoft Visual C++ 2010 Redistributable Package has been installed on your system correctly.

For this:

a. check the Microsoft DDL’s (present) checkbox in the Erlang installer.

b. or manually download the package from the Microsoft’s download center website.

WSE will not work if the package is not found.

Step 2/4

Pay attention to the destination folder name and select one without spaces.

Avoid: “c:\Program Files”, “c:\Program Files (x86)”, “C:\Program Files (x64)”, etc.

and prefer: c:\erl5.9.1\ for Win32 and c:\x64\erl5.9.1\ for Win64.

Step 3/4

Adjust your Path system environment variable by appending the fullpath to

Erlang’s binaries: c:\erl5.9.1\bin;

Now, you can run the Erlang’s VM from everywhere.

Step 4/4

The preferred way to start the Erlang system for interactive use on Windows is:

c:\> werl

Linux

Linux installation could be performed by compiling Erlang from source (advanced users)

or by installing pre-compiled binaries. This second option is highly recommended.

Binaries (.rpm, .deb) for all major distributions (Debian, Ubuntu, CentOS, Fedora,

etc.) are available at:

http://www.erlang-solutions.com/section/132/download-erlang-otp

Repositories are also available to use with your favourite packages manager.

Once installed, your Erlang VM should be under:

/usr/local/lib/erlang

Append this to your PATH environment variable:

$ export PATH=$PATH:/usr/local/lib/erlang/bin

To make this persistent (system wide or user specific), use one of the following

files or better check with your distribution:

/etc/profile.local
/etc/bash.bashrc.local
$HOME/.profile
$HOME/.bashrc

Then, give it a try;

$ erl

Mac OSX

DMG install wizard is also provided to Mac users. The install procedure is almost identical to Linux.

Grab one that fits you at:

http://www.erlang-solutions.com/section/132/download-erlang-otp

Then, run the installer.

Once installed, your Erlang VM should be under:

/usr/local/lib/erlang

Append this to your PATH environment variable (see above how to make it persistent):

$ export PATH=$PATH:/usr/local/lib/erlang/bin

Finaly, check everything’s fine:

$ erl

Other Operating Systems

Drop us a line if interested to use WSE on FreeBSD, SmartOS, etc. We’ll provide you with a detailed instructions and binaries.

Take a breath

Wasn’t that hard? Right?

• You just installed Erlang
• Erlang is different from any other language environment you’ve used before
• An Erlang application is a system of small, independent components
• You can build incredibly complex, robust systems using small, independent components
• The hello module (on the left) is an example of a small, independent component

Lets start with a simple demo, the famous “Hello Web Archiving”.

Save the following code in a file called: hello.erl

-module(hello).
-export([webarch/0]).

webarch() ->
    io:format("WSE says: Hello Web Archiving!~n"),
    halt().

Then, compile and run:

c:\> erlc hello.erl

c:\> erl -noshell -s hello webarch
WSE says: Hello Web Archiving!

Any text editor for my code?

All major IDEs and text editors provide support for Erlang code.

• Eclipse IDE with Erlide plugin
• NetBeans IDE with Erlybird plugin
• IntelliJ IDE with IntelliJErlang plugin
• SciTE editor
• NotePad++ editor
• JEdit editor
• Emacs
• Vi
• KomodoEdit, a fast, smart, free and open-source code editor
• SublimText2 editor with SublimErl plugin: easy to use, lightweight with binaries for Windows, Linux and Mac OSX.

SublimText2 in action

Where can I get more information?

Erlang is a simple functional programming language. Even though the learning

curve is bit steep, you will get more out of it since you will be learning a

functional programming language.

Also, since Erlang was specifically designed to create reliable, highly

concurrent systems, you will learn plenty about creating highly scalable software.

Rather few, but excellent books are available out there.

Learn You Some Erlang (LYSE)

LYSE website provides one of the best, free, complete, and well presented Erlang tutorials to quickly get started.

Help

Aleph Archives is providing a forum in which you can find valuable WSE topics, share ideas,

and ask Erlang questions related to WSE.