dynamodb-waiter-delete-fixed-delay-backoff-strategy-duration
--dynamodb-waiter-delete-fixed-delay-backoff-strategy-duration
is a global parameter for the Liquibase DynamoDB Pro extension. It specifies the number of seconds for the DynamoDbWaiter
to wait before trying to poll your table again (between attempts). This interval is used between calls to verify that the table is 20
.
Uses
When you ask Amazon DynamoDB to run an operation on a resource in your database, such as creating, updating, or deleting a table, DynamoDB calls a waiter class first. Waiters are AWS SDK objects that ensure consistency in distributed systems when DynamoDB doesn't perform operations instantly, but some code needs to wait until those operations are fully completed.
The waiter repeatedly checks whether the table is in the correct state (it "polls" the table). If the table is in the correct state (ACTIVE
or non-existent), the waiter approves the operation. Otherwise, if the table status is CREATING
, UPDATING
, or DELETING
, it tries polling again. The waiter repeats this indefinitely or until it times out. For more information, see Poll for resource states in the AWS SDK for Java 2.x: Waiters.
Note: Liquibase does not use Amazon DynamoDB waiters when you create, update, or delete indexes.
When you run Liquibase commands like update
and rollback
, Liquibase runs your changesets sequentially. For every change, it waits a default amount of time for DynamoDB to respond before moving onto the next changeset. The default waiter settings are appropriate for most situations. However, some operations may require custom waiter values to avoid errors or keep your CI/CD pipeline efficient.
You can customize the following behavior with Liquibase waiter parameters:
- Enabled: whether the waiter makes any polling attempts
- Interval: how long to wait between polling attempts
- Attempts: how many times to attempt to poll the resource
- Timeout: the total amount of time to spend polling
- Exit code: whether Liquibase fails after a waiter timeout
- Logs: whether Liquibase tells you about the status of the waiter, and how often to do so
The --dynamodb-waiter-delete-fixed-delay-backoff-strategy-duration
parameter controls the duration in seconds of the interval between polling attempts:
- If your application is more latency-sensitive, set a lower value (shorter interval). This may reduce the amount of time the waiter takes to detect whether your table is in the correct state.
- If your application is less latency-sensitive, set a higher value (longer interval). This may help you avoid making unnecessary server requests.
Syntax
You can set this parameter in the following ways:
Option | Syntax |
---|---|
Liquibase properties file (defaults file) |
|
Global flow file argument (example) |
|
Global CLI parameter |
|
JVM system property (JAVA_OPTS Environment Variable) |
|
Liquibase Environment Variables |
|
For more information, see Working with Command Parameters.