Calculating DynamoDB costs

CalculateCosts.scala

package edu.berkeley.cs.amplab.carat.dynamodb

import com.amazonaws.services.dynamodb.model.{TableDescription, DescribeTableRequest}
import collection.JavaConversions._

class DynamoDBCostStructure(cp10wu: Double, cp50ru: Double, cpgb: Double) {
  private val costPer10WriteUnits: Double = cp10wu
  private val costPer50ReadUnits: Double = cp50ru
  private val costPerGB: Double = cpgb
  private val hoursPerMonth = 24 * 31

  def monthlyCapacityCost(tableDesc: TableDescription): Double = {
    // We pay a flat hourly rate based on the capacity we reserve
    tableDesc.getProvisionedThroughput.getReadCapacityUnits / 50.0 * costPer50ReadUnits * hoursPerMonth +
    tableDesc.getProvisionedThroughput.getWriteCapacityUnits / 10.0 * costPer10WriteUnits * hoursPerMonth
  }

  def monthlyStorageCost(tableDesc: TableDescription): Double = {
    // We pay for each GB of stored data
    tableDesc.getTableSizeBytes / 1024.0 / 1024.0 * costPerGB
  }

  def monthlyTransferCosts(): Unit = {
    // TODO: We pay for outbound data transfers (~0.12 per GB). Inbound is free.
    Unit
  }
}

/**
 * Program to calculate costs of DynamoDB tables
 */
object CalculateCosts {
  val otherUSCost = new DynamoDBCostStructure(0.01, 0.01, 1.00)
  val norcalUSCost = new DynamoDBCostStructure(0.0112, 0.0112, 1.12)
  val costStructure = otherUSCost
  val delim = ","
  val dollarFmt = "$%.2f"

  def main(args: Array[String]) {
    val tables = DynamoDbEncoder.dd.listTables().getTableNames
    assessTables(tables: _*)
  }
  
  def assessTables(tables: String*) {
    println(Array("name", "capacity cost", "storage cost", "status", "total size bytes",
                  "items", "avg. record bytes").mkString(delim))
    for (t <- tables) {
      val v = DynamoDbEncoder.dd.describeTable(new DescribeTableRequest().withTableName(t)).getTable
      val capacityCost = costStructure.monthlyCapacityCost(v).formatted(dollarFmt)
      val storageCost = costStructure.monthlyStorageCost(v).formatted(dollarFmt)
      println(Array(v.getTableName, capacityCost, storageCost, v.getTableStatus,
        (v.getTableSizeBytes / 1024.0 / 1024.0).formatted("%.2f GB"),
        v.getItemCount, v.getTableSizeBytes/v.getItemCount).mkString(delim))
    }
  }
}