Amazon DynamoDB | Pricing Flashcards
I wish to perform security analysis or operational troubleshooting on my DynamoDB tables. Can I get a history of all DynamoDB API calls made on my account?
Pricing
Amazon DynamoDB | Database
Yes. AWS CloudTrail is a web service that records AWS API calls for your account and delivers log files to you. The AWS API call history produced by AWS CloudTrail enables security analysis, resource change tracking, and compliance auditing. Details about DynamoDB support for CloudTrail can be found here. Learn more about CloudTrail at the AWS CloudTrail detail page, and turn it on via CloudTrail’s AWS Management Console home page.
How will I be charged for my use of Amazon DynamoDB?
Pricing
Amazon DynamoDB | Database
Each DynamoDB table has provisioned read-throughput and write-throughput associated with it. You are billed by the hour for that throughput capacity if you exceed the free tier.
Please note that you are charged by the hour for the throughput capacity, whether or not you are sending requests to your table. If you would like to change your table’s provisioned throughput capacity, you can do so using the AWS Management Console, the UpdateTable API or the PutScalingPolicy API for Auto Scaling..
In addition, DynamoDB also charges for indexed data storage as well as the standard internet data transfer fees
To learn more about DynamoDB pricing, please visit the DynamoDB pricing page.
What are some pricing examples?
Pricing
Amazon DynamoDB | Database
Here is an example of how to calculate your throughput costs using US East (Northern Virginia) Region pricing. To view prices for other regions, visit our pricing page.
If you create a table and request 10 units of write capacity and 200 units of read capacity of provisioned throughput, you would be charged:
$0.01 + (4 x $0.01) = $0.05 per hour
If your throughput needs changed and you increased your reserved throughput requirement to 10,000 units of write capacity and 50,000 units of read capacity, your bill would then change to:
(1,000 x $0.01) + (1,000 x $0.01) = $20/hour
To learn more about DynamoDB pricing, please visit the DynamoDB pricing page.
Do your prices include taxes?
Pricing
Amazon DynamoDB | Database
For details on taxes, see Amazon Web Services Tax Help.
What is provisioned throughput?
Pricing
Amazon DynamoDB | Database
Amazon DynamoDB Auto Scaling adjusts throughput capacity automatically as request volumes change, based on your desired target utilization and minimum and maximum capacity limits, or lets you specify the request throughput you want your table to be able to achieve manually. Behind the scenes, the service handles the provisioning of resources to achieve the requested throughput rate. Rather than asking you to think about instances, hardware, memory, and other factors that could affect your throughput rate, we simply ask you to provision the throughput level you want to achieve. This is the provisioned throughput model of service.
During creation of a new table or global secondary index, Auto Scaling is enabled by default with default settings for target utilization, minimum and maximum capacity; or you can specify your required read and write capacity needs manually; and Amazon DynamoDB automatically partitions and reserves the appropriate amount of resources to meet your throughput requirements.
How does selection of primary key influence the scalability I can achieve?
Pricing
Amazon DynamoDB | Database
When storing data, Amazon DynamoDB divides a table into multiple partitions and distributes the data based on the partition key element of the primary key. While allocating capacity resources, Amazon DynamoDB assumes a relatively random access pattern across all primary keys. You should set up your data model so that your requests result in a fairly even distribution of traffic across primary keys. If a table has a very small number of heavily-accessed partition key elements, possibly even a single very heavily-used partition key element, traffic is concentrated on a small number of partitions – potentially only one partition. If the workload is heavily unbalanced, meaning disproportionately focused on one or a few partitions, the operations will not achieve the overall provisioned throughput level. To get the most out of Amazon DynamoDB throughput, build tables where the partition key element has a large number of distinct values, and values are requested fairly uniformly, as randomly as possible. An example of a good primary key is CustomerID if the application has many customers and requests made to various customer records tend to be more or less uniform. An example of a heavily skewed primary key is “Product Category Name” where certain product categories are more popular than the rest.
What is a read/write capacity unit?
Pricing
Amazon DynamoDB | Database
How do I estimate how many read and write capacity units I need for my application? A unit of Write Capacity enables you to perform one write per second for items of up to 1KB in size. Similarly, a unit of Read Capacity enables you to perform one strongly consistent read per second (or two eventually consistent reads per second) of items of up to 4KB in size. Larger items will require more capacity. You can calculate the number of units of read and write capacity you need by estimating the number of reads or writes you need to do per second and multiplying by the size of your items (rounded up to the nearest KB).
Units of Capacity required for writes = Number of item writes per second x item size in 1KB blocks
Units of Capacity required for reads* = Number of item reads per second x item size in 4KB blocks
* If you use eventually consistent reads you’ll get twice the throughput in terms of reads per second.
If your items are less than 1KB in size, then each unit of Read Capacity will give you 1 strongly consistent read/second and each unit of Write Capacity will give you 1 write/second of capacity. For example, if your items are 512 bytes and you need to read 100 items per second from your table, then you need to provision 100 units of Read Capacity.
If your items are larger than 4KB in size, then you should calculate the number of units of Read Capacity and Write Capacity that you need. For example, if your items are 4.5KB and you want to do 100 strongly consistent reads/second, then you would need to provision 100 (read per second) x 2 (number of 4KB blocks required to store 4.5KB) = 200 units of Read Capacity.
Note that the required number of units of Read Capacity is determined by the number of items being read per second, not the number of API calls. For example, if you need to read 500 items per second from your table, and if your items are 4KB or less, then you need 500 units of Read Capacity. It doesn’t matter if you do 500 individual GetItem calls or 50 BatchGetItem calls that each return 10 items.
Will I always be able to achieve my level of provisioned throughput?
Pricing
Amazon DynamoDB | Database
Amazon DynamoDB assumes a relatively random access pattern across all primary keys. You should set up your data model so that your requests result in a fairly even distribution of traffic across primary keys. If you have a highly uneven or skewed access pattern, you may not be able to achieve your level of provisioned throughput.
When storing data, Amazon DynamoDB divides a table into multiple partitions and distributes the data based on the partition key element of the primary key. The provisioned throughput associated with a table is also divided among the partitions; each partition’s throughput is managed independently based on the quota allotted to it. There is no sharing of provisioned throughput across partitions. Consequently, a table in Amazon DynamoDB is best able to meet the provisioned throughput levels if the workload is spread fairly uniformly across the partition key values. Distributing requests across partition key values distributes the requests across partitions, which helps achieve your full provisioned throughput level.
If you have an uneven workload pattern across primary keys and are unable to achieve your provisioned throughput level, you may be able to meet your throughput needs by increasing your provisioned throughput level further, which will give more throughput to each partition. However, it is recommended that you considering modifying your request pattern or your data model in order to achieve a relatively random access pattern across primary keys.
If I retrieve only a single element of a JSON document, will I be charged for reading the whole item?
Pricing
Amazon DynamoDB | Database
Yes. When reading data out of DynamoDB, you consume the throughput required to read the entire item.
What is the maximum throughput I can provision for a single DynamoDB table?
Pricing
Amazon DynamoDB | Database
DynamoDB is designed to scale without limits However, if you wish to exceed throughput rates of 10,000 write capacity units or 10,000 read capacity units for an individual table, you must first contact Amazon through this online form. If you wish to provision more than 20,000 write capacity units or 20,000 read capacity units from a single subscriber account you must first contact us using the form described above.
What is the minimum throughput I can provision for a single DynamoDB table?
Pricing
Amazon DynamoDB | Database
The smallest provisioned throughput you can request is 1 write capacity unit and 1 read capacity unit for both Auto Scaling and manual throughput provisioning..
This falls within the free tier which allows for 25 units of write capacity and 25 units of read capacity. The free tier applies at the account level, not the table level. In other words, if you add up the provisioned capacity of all your tables, and if the total capacity is no more than 25 units of write capacity and 25 units of read capacity, your provisioned capacity would fall into the free tier.
Is there any limit on how much I can change my provisioned throughput with a single request?
Pricing
Amazon DynamoDB | Database
You can increase the provisioned throughput capacity of your table by any amount using the UpdateTable API. For example, you could increase your table’s provisioned write capacity from 1 write capacity unit to 10,000 write capacity units with a single API call. Your account is still subject to table-level and account-level limits on capacity, as described in our documentation page. If you need to raise your provisioned capacity limits, you can visit our Support Center, click “Open a new case”, and file a service limit increase request.
How am I charged for provisioned throughput?
Pricing
Amazon DynamoDB | Database
Every Amazon DynamoDB table has pre-provisioned the resources it needs to achieve the throughput rate you asked for. You are billed at an hourly rate for as long as your table holds on to those resources. For a complete list of prices with examples, see the DynamoDB pricing page.
How do I change the provisioned throughput for an existing DynamoDB table?
Pricing
Amazon DynamoDB | Database
There are two ways to update the provisioned throughput of an Amazon DynamoDB table. You can either make the change in the management console, or you can use the UpdateTable API call. In either case, Amazon DynamoDB will remain available while your provisioned throughput level increases or decreases.
How often can I change my provisioned throughput?
Pricing
Amazon DynamoDB | Database
You can increase your provisioned throughput as often as you want. You can decrease up to four times any time per day. A day is defined according to the GMT time zone. Additionally, if there was no decrease in the past four hours, an additional dial down is allowed, effectively bringing maximum number of decreases in a day to 9 (4 decreases in the first 4 hours, and 1 decrease for each of the subsequent 4 hour windows in a day).
Keep in mind that you can’t change your provisioned throughput if your Amazon DynamoDB table is still in the process of responding to your last request to change provisioned throughput. Use the management console or the DescribeTables API to check the status of your table. If the status is “CREATING”, “DELETING”, or “UPDATING”, you won’t be able to adjust the throughput of your table. Please wait until you have a table in “ACTIVE” status and try again.
