node.js – 如何聚合AWS SQS ApproximateNumberOfMessages

我实现这一目标的方法是将AWS Lambda与Node.js一起使用.我添加了一个CloudWatch Event触发器,每分钟运行一次lambda函数.这将查询sqs队列,然后创建一个自定义CloudWatch指标,然后您可以使用该指标来扩展自动缩放组.

var AWS = require('aws-sdk');
var sqs = new AWs.SQS();
var cloudWatch = new AWs.CloudWatch();

var queueUrls = ['https://sqs.REGION.amazonaws.com/ACCOUNT-numbER/queueUrl1','https://sqs.REGION.amazonaws.com/ACCOUNT-numbER/queueUrl2'];

exports.handler = (event,context,callBACk) => {
    var fn = function (url) {
        return new Promise(resolve => {
            var sqsParams = {
                Attributenames: ['ApproximatenumberOfmessages'],QueueUrl: url
            };

            sqs.getQueueAttributes(sqsParams,function(err,data){
                if(err)
                {
                    console.log(err,err.stack);
                    context.fail(err);
                }
                else
                {
                    resolve({name: url.split('/').pop(),messageCount: parseInt(data.Attributes.ApproximatenumberOfmessages)});
                }
            }); 
        });
    };

    var actions = queueUrls.map(fn);
    Promise.all(actions).then(function(queues) {
        var messageCount = queues.map(function(m){return m.messageCount;});
        var queuenames = queues.map(function(n){return n.name;}).join();

        var metricParams = {
            MetricData:[{
                MetricName: 'ApproximatenumberOfmessages',Dimensions:[{
                    Name: 'Queuename',Value: queuenames
                }],Unit: 'Count',StatisticValues: {
                    Maximum: Math.max.apply(Math,messageCount),Minimum: Math.min.apply(Math,SampleCount: queues.length,Sum: messageCount.reduce((pv,cv) => pv+cv,0)
                }
            }],Namespace: 'AWS/SQS'
        };
        cloudWatch.putMetricData(metricParams,metricData){
            if(err) console.log(err,err.stack);
            else console.log(metricData);
        });
    });
};

显然可以优化此代码以处理2个以上的队列,并且可能可以从异步瀑布中受益.

编辑：更新以使用承诺.

EDIT2：连接CloudWatch Metric的队列名称