/heartbeat

go heartbeat client/server, golang

Primary LanguageGo

# heartbeat

What Is It?

heartbeat is a go program that demonstrates a simple client server system. The server collects heartbeat signals from multiple clients and displays them in a list.

Installation

If you have a working go installation on a Unix-like OS:

go get github.com/hotei/heartbeat

Will copy github.com/hotei/heartbeat to the first entry of your $GOPATH

or if go is not installed yet :

cd DestinationDirectory

git clone https://github.com/hotei/heartbeat.git

Features

You can provide an "expected" client list such as:

	newClient("JOHN", "10.1.2.124")
	newClient("MARY", "10.1.1.113")
	newClient("FRED", "10.1.2.112")

Uses UDP so heartbeat delivery is not guaranteed - see also bugs.

Demonstrates how client and server can be same program.

If not in the list heartbeat respondees will still show up but with numbers instead of names.

Limitations

  • Uses UDP so heartbeat delivery is not guaranteed - see also features.

Usage

Typical usage is :

On clients: heartbeat -port=2345

On server: heartbeat -server -port=2345

BUGS

none known

To-Do

  • Nice:
    • ServerIPstr should be gotten from command line or automatically,not hardcoded
    • Get client IP from flag/env/syscall?
    • Sort reports by either name or ipnumber (switch without restart)
  • Nice but no immediate need:
    • Add some randomness in client repeater timing to avoid floods? Minor benefit unless we have tons of clients in short interval loop
    • What to do if server consistantly not writable?
    • Use hotei/ansiterm to make updates pretty

Change Log

  • 2015-05-25 validated working with go 1.4.2
  • 2013-03-28 sorted list of system names working
  • 2010-02-21 started, working same day

Resources

  • [go language reference] 1
  • [go standard library package docs] 2
  • [Source for program] 3

Comments can be sent to hotei1352@gmail.com or to user "hotei" at github.com.

License

The 'heartbeat' go package/program is distributed under the Simplified BSD License:

Copyright (c) 2010-2015 David Rook. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Documentation (c) 2015 David Rook

// EOF README-heartbeat.md (markdown tested with blackfriday)