Error UNCERTAIN_STATE with origin ETIMEDOUT and Retry Strategy

Issue

Supposed to have a vpn timeout errors, I get this error on the redis client:

{
                                    "code": "UNCERTAIN_STATE",
                                    "command": "GET",
                                    "args": [
                                        "c9903ac70a7b58e1bef3ff0fe2c9dcd0"
                                    ],
                                    "origin": {
                                        "errno": "ETIMEDOUT",
                                        "code": "ETIMEDOUT",
                                        "syscall": "read"
                                    }
                                    }

I would like to address it through the retry strategy, but current approach does not seem to work:

retry_strategy: function (options) {

                    self.logger.warn("RedisStore.retryStragegy %@", options);

                    if (options && options.error && options.error.code === 'ECONNREFUSED') {
                        // End reconnecting on a specific error and flush all commands with a individual error
                        return new Error('The server refused the connection');
                    }
                    if (options && options.total_retry_time > 1000 * 60 * 60) {
                        // End reconnecting after a specific timeout and flush all commands with a individual error
                        return new Error('Retry time exhausted');
                    }
                    if (options && options.times_connected > 10) {
                        // End reconnecting with built in error
                        return undefined;
                    }
                    // the reconnect retry will happen exactly after this time in milliseconds
                    return Math.max(options.attempt * 100, 3000);
                }

So at this time, as soon as I get the error, the connection fails, and if the VPN turns on, node-redis will hang for ever.

Environment

• v12.16.1

• Redis 5.0.3

• macOS 10.14.5

Start by reproducing the VPN timeout with the retry_strategy shown, then inspect node-redis retry handling for UNCERTAIN_STATE and ETIMEDOUT. Done means the client does not hang indefinitely and reconnects or reports a final error according to the configured retry strategy after the VPN is restored.