Module: Aws::MediaConnect::Waiters
- Defined in:
- lib/aws-sdk-mediaconnect/waiters.rb
Overview
Waiters are utility methods that poll for a particular state to occur on a client. Waiters can fail after a number of attempts at a polling interval defined for the service client.
For a list of operations that can be waited for and the client methods called for each operation, see the table below or the Client#wait_until field documentation for the Client.
# Invoking a Waiter To invoke a waiter, call #wait_until on a Client. The first parameter is the waiter name, which is specific to the service client and indicates which operation is being waited for. The second parameter is a hash of parameters that are passed to the client method called by the waiter, which varies according to the waiter name.
# Wait Failures To catch errors in a waiter, use WaiterFailed, as shown in the following example.
rescue rescue Aws::Waiters::Errors::WaiterFailed => error
puts "failed waiting for instance running: #{error.message}
end
# Configuring a Waiter Each waiter has a default polling interval and a maximum number of attempts it will make before returning control to your program. To set these values, use the ‘max_attempts` and `delay` parameters in your `#wait_until` call. The following example waits for up to 25 seconds, polling every five seconds.
client.wait_until(...) do |w|
w.max_attempts = 5
w.delay = 5
end
To disable wait failures, set the value of either of these parameters to ‘nil`.
# Extending a Waiter To modify the behavior of waiters, you can register callbacks that are triggered before each polling attempt and before waiting.
The following example implements an exponential backoff in a waiter by doubling the amount of time to wait on every attempt.
client.wait_until(...) do |w|
w.interval = 0 # disable normal sleep
w.before_wait do |n, resp|
sleep(n ** 2)
end
end
# Available Waiters
The following table lists the valid waiter names, the operations they call, and the default ‘:delay` and `:max_attempts` values.
| waiter_name | params | :delay | :max_attempts | | ———— | ———————- | ——– | ————- | | flow_active | Client#describe_flow | 3 | 40 | | flow_deleted | Client#describe_flow | 3 | 40 | | flow_standby | Client#describe_flow | 3 | 40 |
Defined Under Namespace
Classes: FlowActive, FlowDeleted, FlowStandby