AWS Dynamodb aggregation的处理问题

方案1：DynamoDB Stream + Lambda方法

 

参考Building NoSQL Database Triggers with Amazon DynamoDB and AWS Lambda: https://amazonaws-china.com/cn/blogs/compute/619/

var AWS = require('aws-sdk');
var sns = new AWS.SNS();
exports.handler = function(event, context) {processRecord(context, 0, event.Records);}

// Process each DynamoDB record
function processRecord(context, index, records) {
    if (index == records.length) {
        context.succeed("Processed " + records.length + " records.");
        return;
    }
    record = records[index];
    console.log("ID: " + record.eventID + "; Event: " + record.eventName);
    console.log('DynamoDB Record: %j', record.dynamodb);
    // Assumes SSN# is only set only on row creation
    if ((record.eventName != "INSERT") || valid(record)) processRecord(context, index+1, records);
    else {
        console.log('Invalid SSN # detected');
        var name = record.dynamodb.Keys.Name.S;
        console.log('name: ' + name);
        var ssn  = record.dynamodb.Keys.SocialSecurityNumber.S;
        console.log('ssn: ' + ssn);
        var message = 'Invalid SSN# Detected: Customer ' + name + ' had SSN field of ' + ssn + '.';
        console.log('Message to send: ' + message);
        var params = {
            Message:  message,
            TopicArn: 'YOUR BadSSNNumbers SNS ARN GOES HERE'
        };
        sns.publish(params, function(err, data) {
            if (err) console.log(err, err.stack);
            else console.log('malformed SSN message sent successfully');
            processRecord(context, index+1, records);
        });
    }
}

// Social security numbers must be in one of two forms: nnn-nn-nnnn or nnnnnnnnn.
function valid(record) {
    var SSN = record.dynamodb.Keys.SocialSecurityNumber.S;
    if (SSN.length != 9 && SSN.length != 11) return false;
    if (SSN.length == 9) {
        for (var indx in SSN) if (!isDigit(SSN[indx])) return false;
        return true;
    }
    else {
        return isDigit(SSN[0]) && isDigit(SSN[1]) && isDigit(SSN[2]) &&
               SSN[3] == '-' &&
               isDigit(SSN[4]) && isDigit(SSN[5]) &&
               SSN[6] == '-' &&
               isDigit(SSN[7]) && isDigit(SSN[8]) && isDigit(SSN[9]) && isDigit(SSN[10]);
    }
}

function isDigit(c) {return c >= '0' && c <= '9';}

 

 

 

 

 

 

 

 

 

 

 

Reference Page:

aws time series process: https://media.amazonwebservices.com/architecturecenter/AWS_ac_ra_timeseriesprocessing_16.pdf

lambda-dynamodb-aggregator: https://github.com/kojiisd/lambda-dynamodb-aggregator

DynamoDB Design Patterns and Best Practices: http://airjd.com/view/ilhadir5000agkt#1