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udpcluster - Lightweight UDP based tool for cluster node discovery
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udpcluster(n) 0.3.3 tcllib "Lightweight UDP based tool for cluster node discovery"


udpcluster - UDP Peer-to-Peer cluster


  • package require Tcl 8.5
  • package require udpcluster ?0.3.3?
  • package require ip
  • package require nettool
  • package require comm
  • package require interp
  • package require dicttool
  • package require cron


This package is a lightweight alternative to Zeroconf. It utilizes UDP packets to populate a table of services provided by each node on a local network. Each participant broadcasts a key/value list in plain UTF-8 which lists what ports are open, and what protocols are expected on those ports. Developers are free to add any additional key/value pairs beyond those.

Using udpcluster.

For every service you wish to publish invoke:

cluster::publish echo@[cluster::macid] {port 10000 protocol echo}

To query what services are available on the local network:

set results [cluster::search PATTERN]
# And inside that result...
   port 10000
   protocol echo

To unpublish a service:

cluster::unpublish echo@[cluster::macid]

Results will Historical Notes:

This tool was originally known as nns::cluster, but as development progressed, it was clear that it wasn't interacting with any of the other facilities in NNS.

Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category nameserv of the Tcllib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide unified diffs, i.e the output of diff -u.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.