Amazon DynamoDB Advanced Bandwidth (iOS SDK)

Question

I am new to DynamoDB. I am very confused about the prescribed bandwidth. I am creating an iPhone game in which users can chat. I have a chat table. The chat table contains GameID, UserID and Message. How to determine the size of an element for calculating throughput. Is the size of the item completely dependent on the right of the message? How to calculate item size?

Amazon says that we can either change the bandwidth using the UpdateTable API, or manually from the console. If I want to change its form code, how do I know if the throughput has been exceeded for a specific table? How to check this from code?

I am also confused about CloudWatch. What does it mean?

Can anyone help me out? Please do not give me the documentation.

Thanks.

Answer 1

I will do my best to help with the confusion.

• DynamoDB is a database with a key: value
• CloudWatch is a tool for monitoring Amazon products.
• Advanced throughput is roughly the number of items you plan to read / write per second.

If you exceed the set bandwidth,

• DynamoDB throws a ProvisionedThroughputExceededException
• DynamoDB notifies CloudWatch

What is a Cloudwatch is basically records and aggregates of data points. For most applications, it will only track aggregated data for every consecutive 5-minute periods.

You can then access this data for “manual” monitoring or configure “alarms”. There was an interesting question about SO a couple of weeks before the start of automatic scaling of DynamoDB using alarms. You might be interested to read it: http://docs.amazonwebservices.com/amazondynamodb/latest/developerguide/ErrorHandling.html

Knowing this, you can start creating your application.

As with all DynamoDB services, credentials are required to access it. Even if they can be limited to a specific table or many actions, it is very dangerous to link them in an application. Could you provide MySQL or MongoDB or credentials, even read only for untrustworthy people?

May I suggest you create an application to rely on your own server? This server, which you trust and build, you can safely perform any authorization check there and give it full access to your table.

Hope this helps. Feel free to ask more questions.