Negligible Participation Metric


    0.1.0 • Public • Published

    Thalassa Client

    A lightweight client for Thalassa

    Running the Client

    The client can be run any of three ways.

    1. From the command-line
    2. As a module
    3. Over HTTP

    Running Client from Command Line

    Why would you do this? Let's say you have an existing legacy Java application that you'd rather not change. You can create a sister service that invokes the command line client to register the service on it's behalf.

    For example, if Thalassa is installed globally (other wise `./node_modules/.bin/thalassa-client):

    thalassa-client --register myapp@1.0.0:8080 --debug

    This registers the application named my app at version 1.0.0 that's on the current host on port 8080. The client will continue to ping the Thalassa server with updates.

    Client Command Line Options

    thalassa-client --help
        --host           thalassa host                                                    [default: ""]
        --apiport        thalassa http api port                                           [default: 9000]
        --register       name@x.x.x:port,name@x.x.x:port                                  [required]
        --secsToExpire   default time in seconds for a thalassa registration to be valid  [default: 60]
        --updateFreq     time frequency in ms to ping the thalassa server                 [default: 20000]
        --updateTimeout  time in ms to wait for a registration request to respond         [default: 2500]
        --debug          enabled debug logging

    Client as an Embedded Module

    Using the client from within a node.js application to register your service is simple. Pass options via the opts object like new Thalassa.Client(opts):

    var Thalassa = require('thalassa');
    var client = new Thalassa.Client({
      apiport: 4445,
      host: 'localhost'
    client.register('myapp', '1.0.0', 8080);
    // start reporting registrations to the server
    // stop reporting registrations to the server

    opts.log may be passed just like the server.

    updateSuccessful and updateFailed Events

    The client will periodically check in with the Thalassa server according to opts.updateFreq (default 5000ms). Each registration will product a updateSuccessful or updateFailed event to be emitted.

    client.on('updateSuccessful', function () {}); client.on('updateFailed', function (error) {});

    Querying Registrations

    Also as a module, you can use the client API to query for registrations.

    client.getRegistrations('myapp', '1.0.0', function (err, registrations) {
        // registrations is an Array of Registrations

    See the HTTP API section for the Registration structure.


    You can also pass metadata with any registration as a fourth parameter. This can be any javascript object with properties. For example:

    var meta = {
        az: 'use1a',
        size: 'm1.large',
        foo: {
            bar: 'baz'
    client.register('myapp', '1.0.0', 8080, meta)


    Licensed under Apache 2.0. See LICENSE file.


    npm i thalassa-http-client

    DownloadsWeekly Downloads






    Last publish


    • mbrevoort