cluster-collector
v1.0.8
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Collect information from all nodes in a NodeJs cluster
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cluster-collector
Collect information from all nodes in a NodeJs cluster. Either from the master node, or any single worker in the cluster. E.g. Used by a REST service to collect cluster statistics aggregation.
Example - Cluster master
const cluster = require('cluster')
const clusterCollector = require('cluster-collector')
cluster.setupMaster({ exec: __dirname + '/demo-child.js' })
cluster.fork({ demo_id: 0 })
cluster.fork({ demo_id: 1 });
(async function() {
//delay for demo. You may want to listen to the 'online' event in production case.
await new Promise(resolve => setTimeout(resolve, 1000))
let options = {
//filter: worker => true, //filter workers to collect from
//timeout: 10000,
data: 'hello' //a custom object to pass on
}
let ret = await clusterCollector.collect('myTopic', options)
console.log('Cluster result collected from master', ret)
})().catch(console.error)
Example - Cluster worker
const clusterCollector = require('cluster-collector')
let demo_id = process.env.demo_id
//Add a handler which generates data for 'myTopic'.
//The handler can be either sync or async
clusterCollector.on('myTopic', async data => data + ' ' + demo_id);
(async function() {
//demo delay
await new Promise(resolve => setTimeout(resolve, 2000))
let options = {
//timeout: 10000,
data: 'mortal' //a custom object to pass on
}
let ret = await clusterCollector.collect('myTopic', options)
console.log('Cluster result collected from a child:', demo_id, ret)
})().catch(e => console.error('error', e.toString()))
.then(() => setTimeout(process.exit, 1000))
Output
Cluster result collected from master [ 'hello 0', 'hello 1' ]
Cluster result collected from a child: 1 [ 'mortal 0', 'mortal 1' ]
Cluster result collected from a child: 0 [ 'mortal 0', 'mortal 1' ]