@mattkirwan/dynamodb-aggregator

DynamoDB Aggregator

A simple utility module for aggregating dynamodb fields. Currently only aggregates per hour.

Install

npm i --save @mattkirwan/dynamodb-aggregator

Usage

const aggregate = require("@mattkirwan/dynamodb-aggregator")

There is currently only one exported function:

Functions

hourly()

---

Params

documentClient - AWS.DynamoDB.DocumentClient - An instance of the DocumentClient from aws-sdk

metaData - Object - An object defining the DynamoDB table/keys you would like to operate against. Example below.

data - Object - An object containing the timestamped events with which you would like to aggregate. Example below.

Examples

metaData

let metaData = {
    TableName: "aggregate_dev",
    PartitionKeyName: "campaign_id",
    SortKeyName: "timestamp_3600",
}

data

// { PartitionKeyX: { AggregateFieldNameX: [ EventTimestamp, EventTimestamp ] } }
let data = {
    // Partition Key
    "1234campaign5678": {
        // Table Field Name
        "total_show": [
            // Events (timestamps in ms)
            1562157215000,
            1562158775000,
            1562162375000,
        ]
    },
    "5678campaign1234": {
        "total_show": [
            1562157215000,
            1562158775000,
            1562162375000,
        ],
        "total_action": [
            1562157215000,
            1562158775000,
            1562162375000,
            1562162375000,
        ]            
    }
}

The above inputs would store the following in DynamoDB:

Use

Returns a Promise.all containing all of the update query responses from the DynamoDB request.

return await aggregate.hourly(documentClient, metaData, data)
    .then(r => {
        console.log(r)
        return
    })
    .catch(e => {
        console.log(e)
        return
    })

Successful response:

{  
    Attributes: {
        total_show: 2,
        campaign_id: '5678campaign1234',
        timestamp_3600: 1562155200,
        total_action: 1
    },
    ConsumedCapacity: {
        TableName: 'aggregate_dev',
        CapacityUnits: 1
    }
}

Tests

It's got a decent amount of unit tests. Run using npm run test.