Month: February 2012

Installing Erlang R15B from source in Ubuntu Oneiric

Download and extract Erlang source code:

wget http://www.erlang.org/download/otp_src_R15B.tar.gz
tar xfvz otp_src_R15B.tar.gz

Install c compiler, make, git and other needed tools to compile just about anything C based in Ubuntu

sudo apt-get install build-essential git-core libwxgtk2.8-dev libgl1-mesa-dev libglu1-mesa-dev libpng3 wx-common default-jre default-jdk fop

Install Erlang build dependencies, this is a shortcut to not having to wonder what dependencies are needed to build Erlang from source

sudo apt-get build-dep erlang

Build and install erlang

./configure
make
make docs
sudo make install
sudo make install-docs

Sharding in ChicagoBoss

ChicagoBoss provides “vertical sharding” out of the box: each model can be stored in a different database or db_adapter.

Sample boss.config where models wiki and author are stored in MySQL and all other models will be using mock db_adapter:

[{boss, [
{applications, [cb_tutorial]},
{db_host, "localhost"},
{db_port, 1978},
{db_adapter, mock},
{log_dir, "log"},
{server, mochiweb},
{port, 8001},
{session_adapter, mock},
{session_key, "_boss_session"},
{session_exp_time, 525600},
{db_shards, [
[
{db_host, "localhost"},
{db_adapter, mysql},
{db_port, 3306},
{db_username, "root"},
{db_password, "password"},
{db_database, "wiki"},
{db_shard_id, first_shard},
{db_shard_models, [wiki, author]}
]
]}
]}].

Note: db_shard_id tuple is required for mysql db_adapter because of the way mysql db_adapter included with CB creates connection pools. Think of it as a connection pool name. DBIdentifier in source code.

Sharding examples are endless: you can persist models of click-stream data to Riak, store content of pages in PostgreSQL, store some logs in Archive type of MySQL database and so on, all based on one configuration file.