[nodemon] app crashed - waiting for file changes before starting..

[ningji]

At this step: setting up socket.io node server

1. ningji@ningji-ThinkCentre-M920q:~/2keep/performance/server$ ag "mongoose.connect"
   socket_main.js
   mongoose.connect("mongodb://127.0.0.1/perfData", { useNewUrlParser: true });

2. when i do "npm start", it keeps on giving this error:

MongooseServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
at NativeConnection.Connection.openUri (/home/ningji/2keep/performance/server/node_modules/mongoose/lib/connection.js:796:32)
at /home/ningji/2keep/performance/server/node_modules/mongoose/lib/index.js:328:10
at /home/ningji/2keep/performance/server/node_modules/mongoose/lib/helpers/promiseOrCallback.js:32:5
at new Promise ()
at promiseOrCallback (/home/ningji/2keep/performance/server/node_modules/mongoose/lib/helpers/promiseOrCallback.js:31:10)
at Mongoose._promiseOrCallback (/home/ningji/2keep/performance/server/node_modules/mongoose/lib/index.js:1149:10)
at Mongoose.connect (/home/ningji/2keep/performance/server/node_modules/mongoose/lib/index.js:327:20)
at Object. (/home/ningji/2keep/performance/server/socket_main.js:2:10)
at Module._compile (node:internal/modules/cjs/loader:1105:14)
at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10) {
reason: TopologyDescription {
type: 'Unknown',
servers: Map(1) {
'127.0.0.1:27017' => ServerDescription {
_hostAddress: HostAddress { isIPv6: false, host: '127.0.0.1', port: 27017 },
address: '127.0.0.1:27017',
type: 'Unknown',
hosts: [],
passives: [],
arbiters: [],
tags: {},
minWireVersion: 0,
maxWireVersion: 0,
roundTripTime: -1,
lastUpdateTime: 114953270,
lastWriteDate: 0,
error: MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017
at connectionFailureError (/home/ningji/2keep/performance/server/node_modules/mongodb/lib/cmap/connect.js:293:20)
at Socket. (/home/ningji/2keep/performance/server/node_modules/mongodb/lib/cmap/connect.js:267:22)
at Object.onceWrapper (node:events:642:26)
at Socket.emit (node:events:527:28)
at emitErrorNT (node:internal/streams/destroy:157:8)
at emitErrorCloseNT (node:internal/streams/destroy:122:3)
at processTicksAndRejections (node:internal/process/task_queues:83:21)
}
},
stale: false,
compatible: true,
heartbeatFrequencyMS: 10000,
localThresholdMS: 15,
logicalSessionTimeoutMinutes: undefined
}
}
[nodemon] app crashed - waiting for file changes before starting...

[ningji]

First of all, this is a great app !

A little bit more info:

1. ubuntu 20.04

2. i don't have yarn, so used npm to install

3. install redis, i followed: https://phoenixnap.com/kb/install-redis-on-ubuntu-20-04
   sudo systemctl restart redis.service

   i do see the UI loads up with cpu/memory status changing, until socket.io node server crashes...