strong-cluster-control

node cluster API wrapper and extensions

It is an extension of the node cluster module, not a replacement.

• runs size workers (optionally), and monitors them for unexpected death
• soft shutdown as well as hard termination of workers
• throttles worker restart rate if they are exiting abnormally

It can be added to an existing application using the node cluster module without modifying how that application is currently starting up or using cluster, and still make use of additional features.

This is a component of the StrongLoop process manager, see http://strong-pm.io.

Install

npm install --save strong-cluster-control

Example

To instantiate cluster-control:

var cluster = require('cluster');
var control = require('strong-cluster-control');

// global setup here...

control.start({
    size: control.CPUS
}).on('error', function(er) {
    console.error(er);
});

if(cluster.isWorker) {
    // do work here...
}

API

See api.

License

strong-cluster-control uses a dual license model.

You may use this library under the terms of the Artistic 2.0 license, or under the terms of the StrongLoop Subscription Agreement.

2018-10-09, Version 2.2.4

• fix: package.json to reduce vulnerabilities (snyk-bot)

• package: correct doc link (Sam Roberts)

• package: replace jscs with eslint 2.x (Sam Roberts)

• Update URLs in CONTRIBUTING.md (#60) (Ryan Graham)

2016-05-03, Version 2.2.3

• update/insert copyright notices (Ryan Graham)

• relicense as Artistic-2.0 only (Ryan Graham)

2016-04-11, Version 2.2.2

• Refer to licenses with a link (Sam Roberts)

2015-10-01, Version 2.2.1

• Sort workers by numeric value of worker ID (Sam Roberts)

• status: preserve the cluster size during restart (Sam Roberts)

• Use strongloop conventions for licensing (Sam Roberts)

2015-09-15, Version 2.2.0

• package: upgrade to tap 1.4.1 (Sam Roberts)

• Refactor restart tests from mocha to tap (Sam Roberts)

• Update eslint to 1.x (Sam Roberts)

• Restart should start new then stop old (Sam Roberts)

• Use formatted debug statements (Sam Roberts)

2015-07-24, Version 2.1.2

• test: update to pass eslint (Sam Roberts)

2015-05-21, Version 2.1.1

• shutdown: don't wait for workers that have exited (Sam Roberts)

• master: sort require statements (Sam Roberts)

2015-05-06, Version 2.1.0

• Avoid nextTick recursion by using setImmediate (Sam Roberts)

• Fix busy-loop on resize after disconnect (Sam Roberts)

• emit custom 'fork' events with s-c-c metadata (Ryan Graham)

• test: clean up lint warnings (Ryan Graham)

• deps: upgrade lodash to v3.x (Ryan Graham)

• Record and report startTime of every process (Ryan Graham)

2015-03-30, Version 2.0.1

• debug: switch from debuglog to visonmedia/debug (Sam Roberts)

• ui: remove unused lib/ui.js and test/ui.js (Sam Roberts)

• package: update jscs ignore rule (Sam Roberts)

• Update README for strong-pm.io (Sam Roberts)

• package: update eslint to 0.17 (Sam Roberts)

• Update README (Sam Roberts)

• lint: add eslint and jscs support (Sam Roberts)

• Fix broken link (Rand McKinney)

2015-01-12, Version 2.0.0

• Remove loadOptions(), its no longer used (Sam Roberts)

• Update dev dependencies to work on Windows (Ryan Graham)

• Add utility to humanize duration (Ryan Graham)

• Add uptime to worker status (Ryan Graham)

• Fix bad CLA URL in CONTRIBUTING.md (Ryan Graham)

2014-12-12, Version 1.0.2

• package: update lodash to ^2.2 (Sam Roberts)

2014-11-03, Version 1.0.1

• status: include current set-size (Sam Roberts)

2014-10-02, Version 1.0.0

• package: remove module names from keywords (Sam Roberts)

• Update contribution guidelines (Ryan Graham)

2014-08-21, Version 0.5.1

• Update package license to match LICENSE.md (Sam Roberts)

2014-07-21, Version 0.5.0

• Update package keywords, sort order, and bins (Sam Roberts)

• Remove control channel and CLI (Sam Roberts)

• Fix link to docs (again) (Rand McKinney)

• Update link to doc (Rand McKinney)

• doc: add CONTRIBUTING.md and LICENSE.md (Ben Noordhuis)

• fix broken links in README (Sam Roberts)

2014-02-19, Version 0.4.0

• Use 'slc clusterctl' in usage when run from slc (Sam Roberts)

• Note existence of strong-supervisor in README (Sam Roberts)

• Prefer cluster to size in command line and config (Sam Roberts)

• example-master, log information about environment (Sam Roberts)

• Install CLI as sl-clusterctl (Sam Roberts)

• Apply Dual MIT/StrongLoop license (Sam Roberts)

• Update jshint (Sam Roberts)

2014-01-25, Version 0.3.0

• Add keywords to npm package (Sam Roberts)

• Include master process ID in status (Sam Roberts)

• Emit 'startRestart' when restart begins (Sam Roberts)

• Emit 'setSize' event after size is set (Sam Roberts)

• Size for loadOptions() allows 0, and mixed case (Sam Roberts)

• Fix example-master, too complicated to be useful (Sam Roberts)

• Clarify debug message about server status (Sam Roberts)

• Clarify debug message about exit (Sam Roberts)

• support windows variations of worker death (Sam Roberts)

• support both windows and unix local sockets (Sam Roberts)

• Test death by signal, as well as worker.destroy() (Sam Roberts)

• Refactor resize test so size can be easily changed (Sam Roberts)

• Add debug messages around server disconnection (Sam Roberts)

• Remove env dump by every worker in debug mode (Sam Roberts)

2013-11-28, Version 0.2.2

• clusterctl reports worker id correctly (Sam Roberts)

• Update README.md (Rand McKinney)

• Remove test code causing test worker to exit (Sam Roberts)

• Worker debug output cleaned up and extended (Sam Roberts)

• Update docs.json (Rand McKinney)

• Extracted API docs into separate file (Rand McKinney)

• Remove blanket from package.json, we use istanbul (Sam Roberts)

2013-11-06, Version 0.2.1

• start/stop stubs for worker return an EventEmitter (Sam Roberts)

2013-10-29, Version 0.2.0

• Revert premature update of package version (Sam Roberts)

• Doc using npm install, not slnode install (Sam Roberts)

• Detect and fail on invalid multiple instantiation (Sam Roberts)

• Add restart command, to restart all workers (Sam Roberts)

• Test reorganized into categories, and size reset (Sam Roberts)

• Throttle worker restarts after an abormal exit (Sam Roberts)

• Test worker, add support for commands in env (Sam Roberts)

• Test worker, add support for exit by erroring (Sam Roberts)

• Setup all workers with _control and birth time (Sam Roberts)

• Use DEBUG or NODE_DEBUG to enable logging (Sam Roberts)

• Keep control.options.size in sync with setSize() (Sam Roberts)

• Support shutting down a cluster (Sam Roberts)

• Fix test failure involving client/server race (Sam Roberts)

• Add master.status(), a public method for cluster state. (Michael Schoonmaker)

• Use blanket ~1.1.5 instead of 'latest' (Sam Roberts)

• Use mocha tap reporter (Sam Roberts)

• Cli factored into a callable function (Sam Roberts)

• Minor edits per style guide. Rm'd dangling API header. (Edmond Meinfelder)

2013-08-29, Version 0.1.0

• Document the loadOptions function (Sam Roberts)

• Optional loading of options from configuration (Sam Roberts)

• Adding docs.json for doc effort. (Edmond Meinfelder)

• Rename control.msg to control.cmd (Sam Roberts)

• update coverage filename (slnode)

• Send SHUTDOWN message before disconnecting (Sam Roberts)

2013-07-15, Version 0.0.2

• First release!