Question

目前我正在使用https://github.com/mranney/node_redis作为我的节点redis客户端。

client.retry_delay默认设置为250毫秒。

我尝试连接到redis，一旦连接成功，我手动停止redis服务器以查看client.retry_delay是否有效。但我没有看到它有效。

以下日志消息记录在ready＆amp;使用createClient

创建的redisClients上的end个事件

[2012-03-30 15:13:05.498] [INFO] Development - Node Application is running on port 8090
[2012-03-30 15:13:08.507] [INFO] Development - Connection Successfully Established to  '127.0.0.1' '6379'
[2012-03-30 15:16:33.886] [FATAL] Development - Connection Terminated to  '127.0.0.1' '6379'

当服务器重新启动时，我没有再看到成功消息[就绪事件未被触发]

我错过了什么吗？何时使用重试常数？是否有解决方案来查找redis服务器是否在节点发生故障后出现？

Answer 1

我无法重现这一点。你可以试试这个代码，停止redis服务器，检查日志输出吗？

var client = require('redis').createClient();

client.on('connect'     , log('connect'));
client.on('ready'       , log('ready'));
client.on('reconnecting', log('reconnecting'));
client.on('error'       , log('error'));
client.on('end'         , log('end'));

function log(type) {
    return function() {
        console.log(type, arguments);
    }
}

Answer 2

@ 2020年2月答案

const redis = require('redis');
const log = (type, fn) => fn ? () => {
    console.log(`connection ${type}`);
} : console.log(`connection ${type}`);

// Option 1: One connection is enough per application
const client = redis.createClient('6379', "localhost", {
    retry_strategy: (options) => {
        const {error, total_retry_time, attempt} = options;
        if (error && error.code === "ECONNREFUSED") {
            log(error.code); // take actions or throw exception
        }
        if (total_retry_time > 1000 * 15) { //in ms i.e. 15 sec
            log('Retry time exhausted'); // take actions or throw exception
        }
        if (options.attempt > 10) {
            log('10 attempts done'); // take actions or throw exception
        }
        console.log("Attempting connection");
        // reconnect after
        return Math.min(options.attempt * 100, 3000); //in ms
    },
});

client.on('connect', log('connect', true));
client.on('ready', log('ready', true));
client.on('reconnecting', log('reconnecting', true));
client.on('error', log('error', true));
client.on('end', log('end', true));

对于完整的示例运行克隆node-cheat，然后运行node connect-retry.js。

Answer 3

添加上面的答案。小变化。提供的回调应该是方法名称，而不是执行方法本身。如下所示：

function redisCallbackHandler(message){
    console.log("Redis:"+ message);
}

var redis = require("redis");
var redisclient = redis.createClient();
redisclient.on('connect', redisCallbackHandler);
redisclient.on('ready', redisCallbackHandler);
redisclient.on('reconnecting', redisCallbackHandler);
redisclient.on('error', redisCallbackHandler);
redisclient.on('end', redisCallbackHandler);

节点JS Redis客户端连接重试

3 个答案: