问Kue - TypeError:无法读取属性'zcard‘的null
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Stack Overflow用户

提问于 2016-02-25 04:02:35

回答 1查看 253关注 0票数 0

TypeError: Cannot read property 'zcard' of null
    at Queue.card (/Users/narain/Sites/integrity-automation/node_modules/kue/lib/kue.js:513:14)
    at Queue.inactiveCount (/Users/narain/Sites/integrity-automation/node_modules/kue/lib/kue.js:616:17)
    at _ (/Users/narain/Sites/integrity-automation/node_modules/kue/lib/http/routes/json.js:318:19)
    at exports.stats (/Users/narain/Sites/integrity-automation/node_modules/kue/lib/http/routes/json.js:41:3)
    at Layer.handle [as handle_request] (/Users/narain/Sites/integrity-automation/node_modules/express/lib/router/layer.js:95:5)
    at next (/Users/narain/Sites/integrity-automation/node_modules/express/lib/router/route.js:131:13)
    at /Users/narain/Sites/integrity-automation/node_modules/kue/lib/http/middleware/provides.js:11:36
    at Layer.handle [as handle_request] (/Users/narain/Sites/integrity-automation/node_modules/express/lib/router/layer.js:95:5)
    at next (/Users/narain/Sites/integrity-automation/node_modules/express/lib/router/route.js:131:13)
    at Route.dispatch (/Users/narain/Sites/integrity-automation/node_modules/express/lib/router/route.js:112:3)
    at Layer.handle [as handle_request] (/Users/narain/Sites/integrity-automation/node_modules/express/lib/router/layer.js:95:5)
    at /Users/narain/Sites/integrity-automation/node_modules/express/lib/router/index.js:277:22
    at Function.process_params (/Users/narain/Sites/integrity-automation/node_modules/express/lib/router/index.js:330:12)
    at next (/Users/narain/Sites/integrity-automation/node_modules/express/lib/router/index.js:271:10)
    at SendStream.error (/Users/narain/Sites/integrity-automation/node_modules/serve-static/index.js:120:7)
    at emitOne (events.js:77:13)
    at SendStream.emit (events.js:169:7)
    at SendStream.error (/Users/narain/Sites/integrity-automation/node_modules/send/index.js:245:17)
    at SendStream.onStatError (/Users/narain/Sites/integrity-automation/node_modules/send/index.js:356:12)
    at next (/Users/narain/Sites/integrity-automation/node_modules/send/index.js:630:16)
    at onstat (/Users/narain/Sites/integrity-automation/node_modules/send/index.js:619:14)
    at FSReqWrap.oncomplete (fs.js:82:15)

在以下情况下，我得到的错误是一致的：

在浏览器窗口中打开kui-ui仪表板
执行优美的关机

我不确定Queue.client是否为null。如果是，那么Queue.prototype.card应该在调用this.client.card之前首先检查this.client是否存在。同样适用于Queue.prototype.cardByType

下面是我的api路由dashboard/stop代码(即停止进程并刷新缓存)：

exports.stop = function(success, failure) {

  let shutdown = new Promise((resolve, reject) => {
    debug('shutting down queue');
    queue.shutdown().then(() => {
      client.flushdb(); // flushing the redis server
      debug('redis is flushed');
      resolve({success: true});
    },
    (err) => {
      reject(err);
    });
  });

  return shutdown;

};

注意：queue是Kue的实例，client是redis的实例

let queue = require('kue').createQueue({prefix: '', redis: config.get('redisurl'), jobEvents: false});

let client = require('redis').createClient({
  'url': config.get('redis') // redis-url
});

还就github提出了同样的问题(问题)：

还没有反应..。

任何想法/想法！怎么解决这个问题..？

node.js

redis

kue

回答 1

Stack Overflow用户

回答已采纳

发布于 2016-03-05 03:55:45

由于Queue.prototype.shutdown实现破坏了客户端(即redis)实例，所以当它调用Queue.prototype.card和Queue.prototype.cardByType时，它会抛出该错误。

至于我的目标是以某种方式停止(暂停)队列进程，然后再继续它。因此，我做了类似的事情，而不是使用Queue.prototype.shutdown，而是使用了Worker.prototype.shutdown，它暂停了工人的(进程)。

queue.js (样本)：

this.queue = kue.createQueue({prefix: opts.prefix, redis: opts.redis, jobEvents: false, disableSearch: false}); // kue instance

stopAllWorkers() {
    return new Promise((resolve, reject) => {
      var length = this.queue.workers.length;
      this.queue.workers.forEach((worker) => {
        worker.shutdown(() => {
          if (--length === 0) {
            resolve();
          }
        });
      });
    });
  }

serverRunner.js (样本)：

var queue = require('./queue');

exports.start = function(success, failure) {
    // resume the queue process
}

exports.stop = function(success, failure) {
  return new Promise((resolve, reject) => {
    queue.removeAllListeners();
    queue.stopAllWorkers().then(() => {
      debug('Queue All workers stopped!!');
      resolve({success: true});
    });
  });
};