sihemo

sihemo is a SImple HEartbeat MOnitoring application. It provides a web interface and a REST API.

Web interface

The web interface exposes a read-only view for live monitoring.

REST API

Get the currently running services and their states

GET /services

Example:

curl localhost:8000/services

Get information about a single service

GET /services/:group/:name

Example:

curl localhost:8000/services/galactica/shields

Sending a heartbeat

POST /services/:group/:name

Send a heartbeat for the specified service.

Parameters:

• alive, an integer indicating how long we assume the component to be alive. If it is not given, the default 30 is used.

Example:

curl -XPOST -d alive=30 localhost:8000/services/galactica/shields

Notify sihemo that a service is down

POST /services/:group/:name

Notify sihemo that the given service is down.

• Parameters:

• state, must be set to down.

Example:

curl -XPOST -d state=down localhost:8000/services/galactica/shields

Shut down a service

DELETE /services/:group/:name

Safely shut down the specified service. This will cause the system not to panic when no further heartbeats arrive.

Example:

curl -XDELETE localhost:8000/services/galactica/shields

Haskell API

(to document)

Ruby client

A simple ruby client is available in ruby/sihemo.rb. Usage example:

s = Sihemo.new('localhost', 8000)
s.heartbeat('galactica', 'shields', 5)
s.down('galactica', 'shields')
s.shutdown('galactica', 'shields')