If network goes down during connection to a redis instance, process crashes

[AVVS]

I wouldn't say that this is really going to happen in the real-life, and probably if it did, the machine is not reachable from the outside, but I think it's not the worst idea to report.

To replicate this - start redis process, make sure it tries to reach something via wi-fi (ip might not exist, but should be valid one), turn off wi-fi and enjoy the crash

events.js:141
      throw er; // Unhandled 'error' event
            ^
Error: connect ENETUNREACH 10.10.100.80:6998 - Local (0.0.0.0:53496)
    at Object.exports._errnoException (util.js:846:11)
    at exports._exceptionWithHostPort (util.js:869:20)
    at connect (net.js:834:14)
    at lookupAndConnect (net.js:927:5)
    at Socket.connect (net.js:896:5)
    at Object.exports.connect.exports.createConnection (net.js:61:35)
    at Connector.connect (/Users/vitaly/projects/mservice-utils/node_modules/arklogger/node_modules/ioredis/lib/connectors/connector.js:28:34)
    at Redis.<anonymous> (/Users/vitaly/projects/mservice-utils/node_modules/arklogger/node_modules/ioredis/lib/redis.js:228:20)
    at tryCatcher (/Users/vitaly/projects/mservice-utils/node_modules/arklogger/node_modules/ioredis/node_modules/bluebird/js/main/util.js:24:31)
    at Promise._resolveFromResolver (/Users/vitaly/projects/mservice-utils/node_modules/arklogger/node_modules/ioredis/node_modules/bluebird/js/main/promise.js:427:31)
    at new Promise (/Users/vitaly/projects/mservice-utils/node_modules/arklogger/node_modules/ioredis/node_modules/bluebird/js/main/promise.js:53:37)
    at Redis.connect (/Users/vitaly/projects/mservice-utils/node_modules/arklogger/node_modules/ioredis/lib/redis.js:214:10)
    at null._onTimeout (/Users/vitaly/projects/mservice-utils/node_modules/arklogger/node_modules/ioredis/lib/redis/event_handler.js:76:12)
    at Timer.listOnTimeout (timers.js:89:15)

[luin]

Seems to be a connection error. When a connection error happens, ioredis would emit error when there's at lease one listener. If there's none of listener listen to the error event, ioredis would just ignore the error and close the connection(and reconnect if retryStrategy is set).

[AVVS]

https://github.com/luin/ioredis/blob/master/lib/connectors/connector.js#L28 - this needs to be patched,
error can be triggered when network device goes down, which should trigger reconnect, not crash. I'll do something raw quickly

[AVVS]

Basically problem is that error happens before you init error listener, because callback is async.

1. stream init
2. nextTick
3. error
4. never gets to .once('error')

    this.connector.connect(function (err, stream) {
      if (err) {
        _this.flushQueue(err);
        reject(err);
        return;
      }

      _this.stream = stream;

      stream.once('connect', eventHandler.connectHandler(_this));
      stream.once('error', eventHandler.errorHandler(_this));
      stream.once('close', eventHandler.closeHandler(_this));