Riak Pi Cluster

Six Raspberry Pi computers running as a utility node and five Riak nodes.

Introduction

This assumes all Raspberry Pi nodes are running Raspbian which comes pre-installed with some unnecessary software and a pi user. The pi user has sudo rights, so this can be used for the initial setup.

Login with username:pi and password:raspberry.

I recommend using something like csshX to manage the cluster and run the install scripts.

Pre-Install Configuration

The Riak Pi Cluster is expected to run as a standalone system with hardcoded IP addresses. These are currently defined in scripts/node/bootstrap.sh in the update_hostname_and_ipaddr function.

You can edit the IP addresses to suit your needs but hostnames are fixed and matched to node MAC addresses during "bootstrap".

Below is an example of a sane IP configuration. You should configure your laptop (if you are also connecting to the switch) to use a neighbouring IP.

utility_eth0_ipaddr="192.168.0.110"
riak1_eth0_ipaddr="192.168.0.111"
riak2_eth0_ipaddr="192.168.0.112"
riak3_eth0_ipaddr="192.168.0.113"
riak4_eth0_ipaddr="192.168.0.114"
riak5_eth0_ipaddr="192.168.0.115"

The bootstrap script installs avahi-daemon which will avoid the need for additional hostname configuration.

Installation

scripts/node/bootstrap.sh - for every node

• Expects to be run as the pi user with sudo on a vanilla install of raspbian
• Creates a basho user with the password demo-cluster and installs demo_cluster_id ssh key
• Sets each nodes hostname and IP address based on hardcoded MAC address
• Updates the ulimit and sets some recommended sysctl tunings for Riak
• Copies necessary setup files to /usr/share/riak-pi-cluster for later use

scripts/riak-node/install.sh - for riak nodes

• Expects to be run as the basho user after bootstrap.sh using updated hostname and IP address
• Runs scripts/riak-node/install-riak.sh
• Runs scripts/riak-node/install-collectd.sh

install-riak.sh

• (If not available locally) downloads pre-built version of Riak 2.0.6 for ARM
• Unpacks Riak to /home/basho/riak
• Configures Riak with settings suitable for Raspberry Pi specifications
• Configures Riak Explorer on riak1.local
• Does not cluster the nodes

install-collectd.sh

• Expects to be run as the basho user after bootstrap.sh using updated hostname and IP address
• Installs collectd
• Configures collectd to curl_json the Riak /stats endpoint
• Configures collectd to send data to graphite on the utility.local node

scripts/utility-node/install.sh - for utility node

• Expects to be run as the basho user after bootstrap.sh using updated hostname and IP address
• Runs scripts/utility-node/install-basho_bench.sh
• Runs scripts/utility-node/install-haproxy.sh
• Runs scripts/utility-node/install-jupyter.sh
• Runs scripts/utility-node/install-monitoring.sh

install-basho_bench.sh

install-haproxy.sh

• Installs haproxy
• Configures an admin view on port 8888 with username admin and password admin
• Configures two haproxy frontends listening on all available IP addresses
  • Protocol buffers frontend on port 8087
  • HTTP frontend on port 8098
• Configures corresponding haproxy backends comprising the riak nodes

install-jupyter.sh

• Installs Jupyter
• Should be started when required with jupyter notebook --ip=0.0.0.0 --port=9999 --no-browser &
• See logins below for access

install-monitoring.sh

Logins & Services

The logins and services setup by the scripts are summarised here:

• Linux login: basho demo-cluster
• Graphite: http://utility.local root password
• Grafana: http://utility.local:3000 admin admin
• HA Proxy Status: http://utility.local:8888 admin admin
• Jupyter: http://utility.local:9999

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• todo: document install-basho_bench.sh
• todo: document install-monitoring.sh