生产用途

让您的 Node.js 应用程序为生产做好准备

以下各节说明如何处理可能发生的情况 在您的生产环境中。

处理错误

Node-Redis 提供了多个事件来处理各种场景，其中最关键的是error事件。

每当客户端内发生错误时，都会触发此事件。

侦听错误事件至关重要。

如果客户端没有注册至少一个错误侦听器并且发生错误，系统将引发该错误，这可能会导致Node.js进程意外退出。 有关更多详细信息，请参阅 EventEmitter 文档。

const client = createClient({
  // ... client options
});
// Always ensure there's a listener for errors in the client to prevent process crashes due to unhandled errors
client.on('error', error => {
    console.error(`Redis client error:`, error);
});

Handling reconnections

If network issues or other problems unexpectedly close the socket, the client will reject all commands already sent, since the server might have already executed them. The rest of the pending commands will remain queued in memory until a new socket is established. This behaviour is controlled by the enableOfflineQueue option, which is enabled by default.

The client uses reconnectStrategy to decide when to attempt to reconnect. The default strategy is to calculate the delay before each attempt based on the attempt number Math.min(retries * 50, 500). You can customize this strategy by passing a supported value to reconnectStrategy option:

  1. Define a callback (retries: number, cause: Error) => false | number | Error (recommended)
const client = createClient({
  socket: {
    reconnectStrategy: function(retries) {
        if (retries > 20) {
            console.log("Too many attempts to reconnect. Redis connection was terminated");
            return new Error("Too many retries.");
        } else {
            return retries * 500;
        }
    }
  }
});
client.on('error', error => console.error('Redis client error:', error));

In the provided reconnection strategy callback, the client attempts to reconnect up to 20 times with a delay of retries * 500 milliseconds between attempts. After approximately two minutes, the client logs an error message and terminates the connection if the maximum retry limit is exceeded.

  1. Use a numerical value to set a fixed delay in milliseconds.
  2. Use false to disable reconnection attempts. This option should only be used for testing purposes.

Timeouts

To set a timeout for a connection, use the connectTimeout option:

const client = createClient({
  socket: {
    // setting a 10-second timeout  
    connectTimeout: 10000 // in milliseconds
  }
});
client.on('error', error => console.error('Redis client error:', error));
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