/**
* Wait for the table to reach the desired status and returns the table description
*
* @param dynamo Dynamo client to use
* @param tableName Table name to poll status of
* @param desiredStatus Desired {@link TableStatus} to wait for. If null this method simply waits
* until DescribeTable returns something non-null (i.e. any status)
* @param timeout Timeout in milliseconds to continue to poll for desired status
* @param interval Time to wait in milliseconds between poll attempts
* @return Null if DescribeTables never returns a result, otherwise the result of the last poll
* attempt (which may or may not have the desired state)
* @throws InterruptedException
* @throws {@link IllegalArgumentException} If timeout or interval is invalid
*/
private static TableDescription waitForTableDescription(
final AmazonDynamoDB dynamo,
final String tableName,
TableStatus desiredStatus,
final int timeout,
final int interval)
throws InterruptedException, IllegalArgumentException {
if (timeout < 0) {
throw new IllegalArgumentException("Timeout must be >= 0");
}
if (interval <= 0 || interval >= timeout) {
throw new IllegalArgumentException("Interval must be > 0 and < timeout");
}
long startTime = System.currentTimeMillis();
long endTime = startTime + timeout;
TableDescription table = null;
while (System.currentTimeMillis() < endTime) {
try {
table = dynamo.describeTable(new DescribeTableRequest(tableName)).getTable();
if (desiredStatus == null || table.getTableStatus().equals(desiredStatus.toString())) {
return table;
}
} catch (ResourceNotFoundException rnfe) {
// ResourceNotFound means the table doesn't exist yet,
// so ignore this error and just keep polling.
}
Thread.sleep(interval);
}
return table;
}
/**
* Waits up to a specified amount of time for a specified DynamoDB table to move into the <code>
* ACTIVE</code> state. If the table does not exist or does not transition to the <code>ACTIVE
* </code> state after this time, then an AmazonClientException is thrown.
*
* @param dynamo The DynamoDB client to use to make requests.
* @param tableName The name of the table whose status is being checked.
* @param timeout The maximum number of milliseconds to wait.
* @param interval The poll interval in milliseconds.
* @throws TableNeverTransitionedToStateException If the specified table does not exist or does
* not transition into the <code>ACTIVE</code> state before this method times out and stops
* polling.
* @throws InterruptedException If the thread is interrupted while waiting for the table to
* transition into the <code>ACTIVE</code> state.
*/
public static void waitUntilActive(
final AmazonDynamoDB dynamo, final String tableName, final int timeout, final int interval)
throws InterruptedException, TableNeverTransitionedToStateException {
TableDescription table =
waitForTableDescription(dynamo, tableName, TableStatus.ACTIVE, timeout, interval);
if (table == null || !table.getTableStatus().equals(TableStatus.ACTIVE.toString())) {
throw new TableNeverTransitionedToStateException(tableName, TableStatus.ACTIVE);
}
}