Chapter 6. Writing and Deleting Table Rows

Table of Contents

Write Exceptions
Writing Rows to a Table in the Store
Writing Rows to a Child Table
Other put Operations
Deleting Rows from the Store
Using multiDelete()

This chapter discusses two different write operations: putting table rows into the store, and then deleting them.

Write Exceptions

There are four exceptions that you might be required to handle whenever you perform a write operation to the store. For simple cases where you use default policies, you can probably avoid explicitly handling these. However, as your code complexity increases, so too will the desirability of explicitly managing these exceptions.

The first of these is DurabilityException. This exception indicates that the operation cannot be completed because the durability policy cannot be met. For more information, see Durability Guarantees.

The second is RequestTimeoutException. This simply means that the operation could not be completed within the amount of time provided by the store's timeout property. This probably indicates an overloaded system. Perhaps your network is experiencing a slowdown, or your store's nodes are overloaded with too many operations (especially write operations) coming in too short of a period of time.

To handle a RequestTimeoutException, you could simply log the error and move on, or you could pause for a short period of time and then retry the operation. You could also retry the operation, but use a longer timeout value. (There is a version of the TableAPI.put() method that allows you to specify a timeout value for that specific operation.)

You can also receive an IllegalArgumentException, which will be thrown if a Row that you are writing to the store does not have a primary key or is otherwise invalid.

Finally, you can receive a general FaultException, which indicates that some exception occurred which is neither a problem with durability nor a problem with the request timeout. Your only recourse here is to either log the error and move along, or retry the operation.