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Worker process coordinator for Node.JS clusters
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Worker process coordinator for Node.JS clusters. It used the built in cluster module to fire up multiple node processes and coordinates the work between them.


npm install usta


usta has 2 different interfaces, one for the master process and one for the worker processes. The basic idea is to have multiple pools of processes. One can define a pool for web server that contains 4 child processes, a single process for background jobs and 2 more for work queue consumers easily.


var usta = require('usta');

if (usta.isMaster) {
    // Necessary
    // Setup the cluster master
        silent: false, // Suppress child process output, default false
        exec: __filename, // The entry point for workers, if not specified, current file is used
        logger: function(log) {…} // A function to intercept logs. Defaults to stdout.

    // Create a new worker pool
    // poolname is required, all config vars are optional, default values are listed below.
    // usta.pool(poolname, options)
    usta.pool('web', {
        ttl: 0, // Time in ms to recycle processes. Children will be restarted in this period.
        size: 0, // Number of child processes required for this pool
        args: {}, // Custom arguments to be sent to children
        env: {}, // Custom environment variables
        strict: false, // If true, pool does not have more than size processes in any case
        killDelay: 60000, // Wait time in ms to forcefully kill a process that does not gracefully exit
        restartDelay: 2000 // Wait time in ms for consecutive restarts

    // Create another pool
    usta.pool('crons', {


var usta = require('usta');

if (!usta.isMaster) {
    // All workers are created equal, therefore it is required to distinguish pools here.
    // Register a function to be called for web workers
    usta.register("web", function() {
        // do whatever you wish

    // Register another type of worker
    usta.register("crons", function() {
        // do whatever you wish



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