migration of Key-Value data from redis into dynamoDB

main.coffee

{AWS} = require './aws' # this is configured aws-sdk
async = require 'async'
redis = require 'redis'
client = redis.createClient(6379, '--our-redis-source--')

data = {}

dynamo = new AWS.DynamoDB()
client.keys '*', (err, res) -> # you can set your pattern
  toTask = (row) ->
    return (cb) ->
      client.get row, (err, value) ->
        return cb(err) if err?
        match = row.match /^([^:]*):(.*)/ # we use colon as column seperator
        (data[match[1]] ?= {})[match[2]] ?= 0
        (data[match[1]] ?= {})[match[2]] += Number(value)
        cb null

  tasks = (toTask(row) for row in res)
  async.parallel tasks, (err, results) ->
    for key, updates of data
      payload = {}
      payload[t1] = { Value: { N: String(t2) }, Action: 'PUT' } for t1, t2 of updates
      console.log payload
      dynamo.updateItem {
        TableName: '--your-dynamo-table-name--'
        Key: Key: S: key
        AttributeUpdates: payload
      }, (err) ->
        throw err if err?
        console.log '.' # FIXME: use async.parallel and process.exit to exit gracefully

# If something goes wrong...
# dynamo.scan {
#   TableName: '--table-name--'
# }, (err, res) ->
#   for item in res.Items
#     dynamo.deleteItem {
#       TableName: '--table-name--'
#       Key: { Key: item.Key }
#     }, -> console.log arguments